Tests Done Under Special Circumstances

If problems with the baby's development are detected by other means or the parents have risk factors for various genetic diseases, special tests may be required. For example, if the mother is age 34 or older, she has an increased risk of having a baby with Down syndrome. So, the parents, in consultation with the obstetrician, may elect to sample fluid or tissue from the baby to determine its genetic make-up. These samples can be obtained through three procedures:

amniocentesis
chorionic villus sampling
fetal blood sampling
fetal monitoring

In these tests, the doctor uses a needle or suction tube to sample fluids or the baby's tissue with the aid of ultrasound to see what he/she is doing. The tissue/fluid samples are analyzed in a laboratory to determine the number of chromosomes (karyotype) and other biochemical tests (e.g., AFP). The results from the tests can be used to make decisions about possibly terminating the pregnancy or preparing the parents to deal with any genetic defects (genetic counseling).

Amniocentesis
Amniocentesis is a test in which the doctor samples the fluid (amniotic fluid) that surrounds the growing baby in the uterus. Floating in the amniotic fluid, there are cells from the baby as well as fluids from the baby (urine). The cells can be grown and the fluid analyzed for various biochemical markers.

Amniocentesis is usually done between 15 to 18 weeks and for mothers with two or more risk factors (e.g., older than age 34, and/or family history of Down syndrome or other genetic diseases). If you were to have this test done, you would go into an examination room with your doctor, an ultrasound technician, and your partner or other family member. The procedure goes like this:

The technician swabs your abdomen with an antiseptic (Betadine).

The technician will use ultrasound to determine where the baby is in your uterus and where there are pockets of fluid away from the baby.

Once these areas are located, your doctor will insert a needle through your abdomen and into the uterus. The doctor constantly monitors the ultrasound to avoid poking the baby.

The doctor withdraws about 30 to 60 ml of amniotic fluid, which the baby will replace within a day.

The doctor places this fluid in one or more sterile cups, marks the cups, and sends them off to a laboratory.

The doctor removes the needle and places a bandage over the site.
You may have another ultrasound exam to assess the baby's health after the procedure.

It takes about two to three weeks before the results of the amniocentesis can be reported.

Amniocentesis has a quoted risk of 0.5 percent, meaning that 1 in 200 procedures have some type of complication (e.g., infection, miscarriage or poking the baby with the needle). In most cases, these percentages are much lower, especially since ultrasound has been used to guide the doctor.

Chroionic Villus Sampling
Like amniocentesis, chorionic villus sampling (CVS) is done to obtain a sample of the baby's tissue for determining genetic disorders. In contrast, CVS obtains tissue from the placenta (chorion) instead of fluid. Because the chorion is derived from the baby, not the mother, it bears the genetic characteristics of the baby. The procedure is similar to amniocentesis except that the tissue can be taken by inserting a needle through the abdomen or a sample tube through the cervix.

Like amniocentesis, CVS is done when the mother has one or more risk factors for genetic diseases. CVS can be done earlier than amniocentesis, usually in the latter part of the first trimester ( between weeks nine and 11). The results of CVS can be obtained sooner than amniocentesis because no culturing of the tissue is required. However, because CVS only gets tissue, some of the biochemical tests done with amniocentesis cannot be done with CVS. Also, CVS carries a higher risk (about 1 percent), mostly because it is a newer procedure relative to amniocentesis.

Fetal Blood Sampling
Fetal blood sampling can be done from 18 weeks to full term. In this procedure, fetal blood is obtained from the umbilical cord for analysis. Like amniocentesis, the doctor (aided by ultrasound) inserts a needle through the mother's abdomen into the umbilical cord and withdraws a blood sample. The blood sample is sent to a lab for analysis. The genetic results from fetal blood sampling can be obtained much faster than with amniocentesis because no tissue culturing is involved. In addition, this technique can be used to transfuse the fetus with compatible blood in the event that the baby's and mother's Rh factors do not match. The overall risk of the fetal blood sampling procedure is 0.5 - 1 percent.

Fetal Monitoring
Fetal monitoring is usually done in the third trimester (for high-risk pregnancies, pre-term labor or overdue babies) and during delivery. This test involves strapping an electronic monitor to the mother's abdomen that measures the electrical activities of the following:

fetal heart beat
mother's heart beat
mother's uterine muscle contractions
The baby's movements inside the uterus can be assessed and correlated with its heart rate. There are two types of test done:

Non-stress test - the baby's heart rate should increase when the baby moves (about 15 beats for 15 seconds at least twice in a 20 minute period).

Stress test - the baby's heart rate should increase when the uterus contracts. Uterine contractions are caused by infusing a medication (Pitocin) or by stimulating the mother's nipples.

These tests are used by obstetricians to determine how well the baby will handle the stress of delivery.

As you can see, there are a wide variety of ways to measure your baby's growth and development before it is born. Prenatal testing is completely normal during pregnancy and can often detect problems early, before they progress.

Ultrasound

You may have one or more ultrasound tests during your pregnancy. The first test may be done within the first four weeks to date the pregnancy and determine the due date. This is done by measuring the baby's crown to rump length. Accurate charts are available to determine the age of the fetus from these measurements.
By about weeks 11 to 13, ultrasound may be used to examine various aspects of your baby's developments, such as:

Is the neural tube closed?
Are the internal organs developing properly?
Does the heart beat OK, and at what rate?
By 20 weeks, you may be able to determine the sex of the baby by observing its sex organs with ultrasound.

Swab Tests

At different times during pregnancy, your doctor may take swab samples (Q-tip) from your vagina or rectum. The cells on the swab will be examined under a microscope or cultured to determine various conditions or diseases.

In the first trimester, you may have a Pap smear in which cells from your cervix are examined to look for signs of cervical cancer. Later, when you are closer to delivery (around week 35), your doctor will take swabs from your vagina and rectum. These swabs will be cultured to look for Group B streptococcus bacteria. These bacteria are common in many women and are considered a normal part of an adult woman's reproductive system. For an unborn child, however, these bacteria can spread during delivery and cause several problems:

respiratory distress - problems with breathing that threaten the baby's life
mental retardation
vision problems
hearing loss
Group B strep infections can be treated with IV antibiotics before delivery.

Blood Sampling Tests

In the first trimester of pregnancy, you may have blood drawn to determine the following:

hCG levels (discussed above)
Blood iron content - important for hemoglobin and delivering sufficient oxygen to the growing baby

Blood type and Rh compatibility - assess problems between mother and baby's blood types (see Rh Blood Testing for details)

Presence of antibodies to viruses (e.g., HIV, hepatitis B) or presence of bacteria (e.g., syphilis).

The hCG, viral antibody, syphilis and blood type tests look for and/or quantify the amount of antibodies to these substance in the blood. The iron test directly measures the iron by burning a sample in a high temperature flame and quantifying the amount of light given off at the wavelength of light specific for iron, which is related to the amount of iron present.

Glucose Tolerance Test
Between week 25 to 28 gestation, you will have a glucose screening test for gestational diabetes. You will drink a soda containing high amounts of glucose, or sugar, and will have your blood drawn one hour later. Blood glucose will be measured by a glucose oxidase reaction described in the previous section. If the glucose level is high, you may be asked to take an additional glucose-tolerance test. In this test, you drink a high-glucose solution on an empty stomach and blood samples will be taken at regular intervals (usually every hour) for three hours. Blood glucose levels will be measured again. The timecourse information from a glucose tolerance test is a better indication of your body's response to a glucose load to diagnose gestational diabetes.

Neural Tube Defects
The baby's brain and spinal cord develop from the outer layer of the embryo called the ectoderm. The ectoderm dimples inward along the long axis of the embryo, the two edges come together, the edges seal and the folded portion pinches off to form a tube (neural tube). The nervous system, including the brain and spinal cord, develop from the neural tube. If the neural tube does not close, then a condition called spina bifida develops and the baby's brain and spinal cord do not develop properly, resulting in mental handicaps and even death. Neural tube defects can be prevented by supplementing the mother's diet with folic acid (a major component of prenatal vitamins).

Triple Screen Test
This test is done in the second trimester and measures three parameters:

alpha-fetoprotein (AFP)
hCG
estriol
AFP is produced by the baby and makes its way into the mother's blood. Typically, AFP levels are low. However, high levels of AFP indicate that the baby's neural tube has failed to close (i.e., a neural tube defect). An ultrasound examination may then be done to confirm this finding.

At this time in development, hCG levels in combination with AFP levels can tell us whether the baby has any abnormalities in the number of chromosomes. A high level of hCG in combination with a low level of AFP suggests a chromosomal abnormality. The most common disorder of this type is Down syndrome (extra chromosome #21 -- see Human Chromosomal Abnormalities for more details). If the level of hCG is high and no fetal heartbeat is detected, then there may be a molar pregnancy. A molar pregnancy is when a piece of tissue, usually leftover from a previous pregnancy, grows rapidly, destroys the baby and forms a benign tumor. An ultrasound examination may then be done to confirm this finding.

Estriol is a hormone made by the baby's adrenal glands. The levels of estriol in the mother's blood indicate the health of the baby. If the estriol levels drop, then the baby may be threatened and need to be delivered. Low levels of estriol may also indicate Down syndrome or neural tube defect.

Routine Non-Invasive Tests

These tests are done every time you visit your obstetrician and include:

blood pressure
urine glucose
urine protein
fetal heartbeat - beginning when the baby's heart is developed enough to to be heard
Blood Pressure

The increased blood volume and fetal blood circulation that occurs in pregnancy increases the demands on your cardiovascular system, especially your heart. So, your blood pressure will be measured regularly to detect any signs of high blood pressure or pregnancy-induced hypertension. About five percent of pregnant women experience pregnancy-induced hypertension starting about the 20th week of pregnancy. This condition can can lead to the following complications:

Pre-term labor
Separation of the placenta, leading to bleeding
Reduced kidney function or failure
Reduced blood flow to the baby, which can retard its growth and development
Pregnancy-induced hypertension, along with swelling (edema) and protein in the urine (albuminuria), comprise a condition known as preeclampsia. The cause of pre-eclampsia is unknown and the treatment is premature delivery of the baby, if possible. Sometimes, high doses of magnesium sulfate can be given to delay the symptoms until the baby can be delivered safely; no one knows why this treatment can work.

Your blood pressure will be measured with a blood pressure gauge or sphygmomanometer (read this question about blood pressure gauges for more details).

Urine Glucose
During each doctor's visit, you will be asked to pass a test strip through your urine stream or collect a sample of urine, which will be tested with a strip that measures the amount of glucose in your urine. The presence of glucose in the urine is an indication of gestational diabetes, a form of diabetes that usually develops around the 20th week of pregnancy. Gestational diabetes causes the following complications:

The baby grows larger than normal and develops more fat. Large babies are difficult to deliver.

The baby's pancreas must secrete large amounts of insulin to get rid of the excess sugar coming from the mother. After birth, when the baby is no longer receiving these high amounts of sugar from the mother, the high insulin levels can cause the baby's blood sugar to fall dangerously low (i.e., hypoglycemia).

Some babies from mothers with gestational diabetes have trouble breathing when they are delivered (i.e., respiratory distress).

Gestational diabetes can be treated usually by monitoring the mother's diet. However, sometimes the mother must take insulin to control her blood glucose levels. Gestational diabetes in the mother usually goes away once the baby has been delivered.

The test strip contains two enzymes (glucose oxidase and peroxidase), a chemical (orthotolidine) and a yellow dye impregnated in the paper. The reactions go like this:

Glucose oxidase converts glucose into gluconic acid and hydrogen peroxide.
Peroxidase reacts the hydrogen peroxidase with orthotolidine to produce a blue color.
The yellow dye spreads the color change out over a wider range in proportion to the amount of glucose present.
If no glucose is present, then the test strip remains yellow. If glucose is present, then the color can vary from light green to dark blue, depending upon the concentration of glucose in the urine.

Urine Protein
The presence of protein in the urine indicates a problem in kidney function and is one of the symptoms of pre-eclampsia, as mentioned above. To detect protein in the urine, the test strip has a pH buffer (citrate buffer) and a color indicator (bromphnol blue) impregnated in the paper. At the normal pH of the paper, most of the indicator is not ionized. Proteins can bind to the nonionized form and release hydrogen ions, which changes the pH and the color of the paper. If protein is present, then the color of the paper will change from yellow to green or blue, depending upon the concentration of protein.

Fetal Heartbeat
One of the more emotional times in an early pregnancy may be the first time you hear the baby's heartbeat. The baby's heartbeat can be seen in a Doppler ultrasound as early as five to six weeks of development. By 12 to 13 weeks, your doctor can hear the heartbeat using a specialized ultrasound stethoscope or Doppler stethoscope. The Doppler stethoscope works like a regular ultrasound machine except that it does not give an image. Instead, the echoes are counted and the count is displayed on a LCD readout. If the stethoscope has a speaker, you can hear the baby's amplified heart beat.

The Pregnancy Test

This test is usually the first test conducted when you suspect that you may be pregnant. There are a variety of home testing kits available over-the-counter and all detect a protein hormone called human chorionic gonadotropin (hCG). When an egg is fertilized, the embryo begins to produce hCG. Levels of hCG increase after conception and can be detected in the mother's urine. By 10 days after conception, hCG levels are about 25 milli-International Units (mIU).

Typically, the home test is a urine test for hCG:

You collect a sample of urine. You would usually use the first urine in the morning, when hCG levels are the most concentrated, or wave the test wand through the urine stream.
If you collected the urine, you can either dip the test wand into the cup or place a drop on the test wand.

The test wands or dipsticks have a plastic coating embedded with antibodies to hCG.
The test wands also have a second antibody to hCG linked with some color tag (e.g., colored latex beads, enzyme that produces a color reaction).

If sufficient levels of hCG are present in the urine (more than 25 mIU), then the hCG will bind with the second antibody and cause a color reaction to occur (i.e., a positive test result).

If a positive test occurs, you generally call your doctor and a second test is performed at the office to confirm the pregnancy. The doctor may also order a blood test to determine the precise quantity of hCG present, which can be used to assess the baby's health.

Pregnancy Involves Many Tests

Throughout the course of a pregnancy, an expecting mother will have many tests. They fall into the following categories:
pregnancy test - the first test
routine, non-invasive tests - these occur during each visit to the obstetrician's office
blood pressure
urine glucose/protein
fetal heartbeat
blood sampling tests - usually done once at various times during pregnancy
blood type, Rh Factor
determine iron levels
HIV, Hepatitis B, syphilis
glucose tolerance test
triple screen test
swab tests - usually done once at various times during pregnancy
Pap smear - to check for STDs, various bacteria (varies according to the laws of each state)
Group B streptococcus screening
ultrasound - done at least one time during pregnancy
tests done under special circumstances
amniocentesis
chorionic villus sampling
fetal blood sampling or percutaneous umbilical blood sampling
fetal monitoring
Let's look at the various tests to see how they work and what they can tell us about the developing baby.

Labor

In movies, pregnant women experience a dramatic rush of fluid as their water breaks. But in reality, very few women will have their water "break" (which is actually the breaking of the amniotic sac). Most of the time, the nurse or midwife will break the amniotic sac once labor has already begun.

Signs of labor include:

Contractions that increase in frequency, duration, and intensity
Lower back pain that doesn't go away
Cervical dilation (opening up), revealed during a pelvic examination
A mother has many options when it comes to giving birth. She can deliver in a hospital or birthing center with the help of an obstetrician or midwife, or at home with the help of a midwife. She can also hire a doula -- a trained professional who offers support during the birthing process. Doctors recommend that women with high-risk pregnancies deliver in a hospital, because medical facilities are best equipped to handle emergencies should they occur.

The labor process typically consists of several stages.

During early labor, the mother will feel the first contractions. Her cervix will gradually efface and dilate in preparation for delivery. The contractions will be more frequent and become more painful. For many women, the early stage of labor can last for hours, and doesn't necessarily require an immediate trip to the hospital. The contractions come more frequently during active labor. They are also more painful -- sometimes too painful for the mother to talk through. Once the contractions start coming about every five minutes for an hour, the mother should call her doctor and get ready to go to the hospital. The mother's cervix continues to ripen -- it must stretch from about three centimeters to the full 10 centimeters before delivery can begin. Once she reaches the hospital and is dilated sufficiently, the mother can have medication for her pain if she chooses to do so. Options include an epidural (anesthesia injected into the woman's spinal cord, which blocks sensation in her lower body) and an intravenous pain reliever.

In the transition stage, the cervix reaches its full dilation as contractions become stronger and even more frequent. They may come every three minutes and last up to a minute each. The baby is also descending into the birth canal in preparation for delivery. As the baby moves down, the mother may feel pressure (as if she needs to have a bowel movement), and an urge to push. This stage may last anywhere from a few minutes to a few hours. Labor typically progresses more slowly for first-time moms.

Third Trimester

During the next 12 weeks, the fetus will finish its development and prepare for the difficult birth process. It is now about 15 inches long and weighs between two and three pounds. Its eyes are a definite color (although they may change after it is born) and are fringed with lashes. Its body is rounding out as fat deposits under its skin. This fat will help its body regulate temperature once it is born. Its brain is becoming larger and more defined, and its skull is growing to accommodate it. If it is a boy, his testicles are descending into his scrotum. If the fetus is a girl, her clitoris is developed.

As the mother's belly swells, she may be in more discomfort, especially near the end of her pregnancy. She might experience hemorrhoids and insomnia. The pressure of the growing uterus on her diaphragm may also make her feel short of breath. It can press down on nerves, causing pain in her lower back and legs, and constrict her bladder, making her run to the bathroom constantly. Many women feel tired and have difficulty sleeping because of their increasing girth.


Sometime during the third trimester, the muscles of the mother's uterus begin contracting. These Braxton-Hicks contractions are practice to help the mother's body prepare for labor. Frequent or painful contractions could be a sign of premature labor.

By week 32, the fetus can move its eyes back and forth and tell the difference between light and dark. It is gaining weight quickly -- about a half pound per week. At this stage in the pregnancy, the fetus weighs just over four pounds and measures 15 to 17 inches long. It may have a full head of hair as well as fingernails and toenails.

The mother's uterus is getting very crowded. Although the fetus continues to move, its movements won't be as fervent as they were earlier in the pregnancy.

At week 35, the fetus measures between 15 and 18 inches long and weighs five-and-a-half to 6 pounds. The lanugo starts to fall off. The vernix caseosa, which protected its body in the amniotic fluid, also disappears. Its organs are almost fully developed.

From this point on, the mother will probably visit her doctor every week until the baby is born. The doctor may do a culture of the mother's vagina to test for bacteria called Group B streptococci, or Group B strep. Mothers who test positive for this bacteria will get intravenous antibiotics during labor to reduce their risk of passing the infection to their baby during labor.

By this point in the pregnancy, the fetus has probably rotated so that it is head down in preparation for birth. Babies that are turned the wrong way are called breech deliveries, but there are ways of turning the baby before labor begins. As her baby drops lower in her pelvis, the mother may feel relief from the breathlessness and other symptoms that have plagued her for the last few weeks.

Although delivery is still a few weeks away, at week 37 the fetus is considered full term. This means that if it were delivered now, it would be able to function outside the womb. It should weigh at least 6 pounds and measure between 19 and 20 inches. At any time between now and the onset of labor, the mucus plug which had blocked the entrance to the mother's cervix to prevent bacteria from entering will come out. This is a sign that labor is on its way.


In the last few weeks of pregnancy, the mother's doctor will check to see how far she has "effaced" or "ripened." Effacement is the process by which the cervix softens and thins to prepare for delivery. When the mother is 100-percent effaced, she is almost ready for labor.

Week 40 officially marks the end of the pregnancy, but only a small percentage of women actually deliver on their due date -- many are either early or late. If the baby has still not been delivered by week 41 or 42, the doctor will probably induce labor.


Pregnancy Myths
Myth: If you are carrying low, the baby is a boy. If you are carrying high, it's a girl.
Reality: The fetus' position in the mother's abdomen bears no relation to its sex. There are only two ways to find out if you're having a girl or a boy: amniocentesis or ultrasound.
Myth: If you have heartburn often during pregnancy, your baby will be born with a lot of hair.
Reality: Heartburn is common to all pregnant women, whether their baby is born bald or with a full head of hair.

Myth: Spicy food (or a particular dish) will cause labor.
Reality: There is no evidence that any type of food -- no matter how spicy -- can trigger labor.

Myth: Having sex will trigger premature labor.
Reality: Although sex might be uncomfortable as the mother's tummy grows, no research indicates that it will trigger premature labor. However, if the mother is bleeding during pregnancy, or if her partner has a sexually transmitted disease, her doctor may advise her against having intercourse until the baby is born.

Myth: If the mother holds her arms above her head, the umbilical cord will strangle the baby.
Reality: Although a very small percentage of babies are born with the umbilical cord wrapped around their necks, the placement of the cord has absolutely nothing to do with the way the mother holds her arms.

Second Trimester: Halfway There

At week 20 -- halfway through the pregnancy -- the fetus is about six inches long and weighs about 10 ounces. Its digestive system produces meconium, a black, tar-like substance that will make up its first few bowel movements. The fetus is coated in a white greasy substance called vernix caseosa, which will protect its skin from the amniotic fluid in utero.

To train its digestive system and lungs, the fetus will swallow and "breathe" amniotic fluid. Its lungs produce a substance called surfactant, which will enable the air sacs to inflate for breathing once it is born.

At this point in the pregnancy, the mother may develop acne because of her skin's increased oil production. She may also develop varicose veins, which are caused when valves malfunction and allow blood to pool in the legs. Other changes include larger breasts, skin discoloration, heartburn and constipation. Nasal congestion is common as more blood flows through the mucous membranes, and the mother's legs may cramp as her uterus puts pressure on veins. Some mothers are more prone to bladder infections due to hormonal changes.

Between 24 and 28 weeks, the Ob/Gyn will perform a glucose screening test to check the mother for gestational diabetes, a form of diabetes in which the mother does not produce enough insulin. If she does have gestational diabetes, she will have to control her blood sugar with diet and may need insulin injections.

Placenta previa may also become apparent during this time. Mothers with this condition have a placenta that hangs low in the uterus and blocks the cervical opening to the birth canal. If placenta previa continues into late pregnancy, the mother will have to deliver by caesarean section.

Week 27 marks the end of the second trimester. By now, the fetus has grown to about 14 inches long, and weighs about 2 pounds. It is already starting to look like a newborn baby. If born at this point, the baby may survive, but would face potentially serious problems.

Second Trimester: The Kicking Fetus

For many women, the second trimester is a definite improvement. As the nausea recedes and exhaustion abates, many women feel better and have more energy -- and appetite -- during this period. However, some women develop other unpleasant symptoms, such as heartburn.

Other changes occur in the mother's body. Even though her fetus is just a few inches long, her belly is growing. Mammary ducts inside her breasts prepare to produce milk. During this trimester, the mother's breasts will start to produce a yellowish, nutrient-rich substance called colostrum, which will feed her baby during its first few days of life.

Inside her womb, the rapid activity continues. Although the mother may not be able to feel it yet, the fetus now kicks and moves. Its head -- which just a few weeks ago dwarfed the rest of its body -- is now more proportional. A fine hair called lanugo covers its body. The kidneys and urinary tract start to produce urine and release it into the amniotic fluid. The liver begins secreting bile, and the spleen begins to aid in the production of red blood cells.

By week 15, the fetus is around five inches long and weighs about two ounces. Although its eyelids are fused shut, its eyes are now sensitive to light.

The mother will make her second prenatal doctor visit between weeks 12 and 16 of her pregnancy. At this visit, her Ob/Gyn may perform an ultrasound to look at the baby. Sometimes the doctor can determine the sex during this visit. The doctor will probably also measure the fundus -- the distance between the top of the mother's pubic bone and the top of her uterus. This measurement will allow the doctor to track the fetus' growth throughout the pregnancy.

Tests done during this trimester include an Alpha-Fetaprotein (AFP) or triple test -- a blood test that detects levels of alpha-fetoprotein (a protein produced in the fetus's liver) to identify Down syndrome or spina bifida. If the mother is over age 35, she might also have an amniocentesis, a procedure in which the doctor inserts a thin needle into her abdomen and removes a small sample of amniotic fluid to test for birth defects and chromosomal abnormalities. Between weeks 16 and 20, the fetus begins to hear and may even be able to hear the sound of its mother's voice. It can frown, squint, and make other facial expressions. The fetus' scalp is sprouting tiny hair buds, its skeleton is hardening, and millions of tiny neurons in its brain help its muscles move. Its tiny heart pumps about 25 quarts of blood each day. Its reproductive organs are forming. If the fetus is a girl, her ovaries are beginning to produce the millions of eggs that she will possess for her entire lifetime. During this period, the mother may start to experience "quickening" -- feeling her tiny fetus kick.

The mother's body continues to undergo numerous changes. Often, pregnant women appear to "glow." Although many women are truly suffused with the joy of pregnancy, the glow is often due to increased blood flow to the face. Many women also have a dark line running from their belly button to their pubic bone. This line, called linea nigra, occurs because of an increase in skin pigmentation, or melanin. It should disappear shortly after the baby is born. Some women also develop stretch marks -- thin pink or brown lines on their belly which often fade soon after the baby is born. Another common problem is edema, swelling of the ankles and feet due to fluid retention. Severe swelling in the hands and face could be a sign of a potentially dangerous condition called pre-eclampsia, which prevents the placenta from getting enough blood.

First Trimester: From Embryo to Fetus

Even though the embryo is still the size of a sesame seed, the mother-to-be will probably start feeling the first twinges of pregnancy. Morning sickness, frequent urination, sleepiness, and food cravings or aversions are all common. Her breasts may swell and become tender. Some women start to put on weight, but others actually lose weight from morning sickness. At this point in the pregnancy, the woman will have her first prenatal Ob/Gyn visit. By the fifth week, an ultrasound may be able to pick up a heartbeat.

The mother needs to be especially careful during this first trimester, during the formation of the delicate organs. Pregnant women should avoid alcohol, certain medications, caffeine, and smoking. They should also continue to take prenatal vitamins containing folic acid, eat a healthy diet and exercise regularly.

Between 9 and 12 weeks, women over age 35 and those who have a family history of chromosomal abnormalities will probably have a chorionic villus sampling (CVS). This test detects Down syndrome and other chromosomal abnormalities. Using an ultrasound to guide him, the doctor will remove a small piece of placental tissue and test it for these conditions.

In the last few weeks of the first trimester, the embryo really starts to take shape. The facial structures begin to form and become recognizable. The neural tube, which will form the brain and spinal cord, develops. Little buds emerge and grow into arms and legs.

Around week 8, the embryo becomes a fetus. The kidneys, liver, brain, and lungs are all beginning to function. The fingers and toes are separate and the external genitalia are formed. At 12 weeks, the fetus is about three inches long and weighs about one ounce. At the end of the first trimester, many pregnant women find that their clothes are getting tight, although they may not yet be ready for maternity clothes.


Miscarriage
About 15 percent of pregnancies end in miscarriage -- most within the first trimester [March of Dimes]. As many as 50 percent of pregnancies may end in miscarriage, but most occur so early that the woman did not even realize that she was pregnant.

Most pregnancies end because of a chromosomal abnormality, a problem with either the egg or the sperm. Women who are over the age of 35 are at greater risk for these abnormalities -- and at greater risk of having a miscarriage -- than younger women. Other causes of miscarriage are infections, hormonal problems, or an illness or disease (such as diabetes). Drinking alcohol, smoking cigarettes, and taking certain drugs can also increase the risk. Fortunately, most women who have a miscarriage can go on to have a healthy, problem-free pregnancy in the future.

First Trimester: From Conception to Embryo

A man releases millions of sperm with each ejaculation. Once inside the woman's body, the sperm make a mad dash to find the egg. If one sperm reaches the egg and penetrates it, fertilization occurs.

Then things start progressing rapidly inside the mother's womb. The sperm and egg merge to form a little single-celled organism called a zygote, which consists of the 23 chromosomes from the man's sperm and the 23 chromosomes from the female's egg. These chromosomes will determine the baby's hair color, eye color and whether the baby will be a boy or a girl.

Soon after fertilization, the zygote makes the trip through the Fallopian tubes to the uterus. During this journey, the zygote divides. Within 72 hours, it will have gone from one cell to eight cells.

Pregnancy Tests

Some women know immediately that they're pregnant -- call it a new mother's intuition. However, the only way to know for sure is to take a pregnancy test. All pregnancy tests look for the same thing: the presence of human chorionic gonadotropin (hCG), a hormone produced only during pregnancy.

Home pregnancy tests measure hCG in urine, while a test in the doctor's office will identify hCG in a blood sample The blood test can pick up very tiny amounts of the hormone and identify pregnancy earlier than a home pregnancy test. Still, most home tests are 97 to 99 percent accurate if taken correctly.

Remember the zygote? This little ball of cells divides until it contains about 100 cells. Then it becomes known as a blastocyst. The inner group of cells will form the embryo. The outer group of cells forms the placenta, which will provide nourishment.

Three weeks into the pregnancy, the blastocyst implants itself into the mother's uterine wall and releases hCG. This occurs only a few days after conception. Her doctor will begin counting the 40 weeks of pregnancy from the start of her last period, although conception normally occurs about two weeks after that.


The fertilized egg makes the journey through the Fallopian tube to the uterus, where it will implant.

By the fifth week of the pregnancy, the brain, spinal cord, heart, and other organs begin to form. The embryo is now made up of three layers: the ectoderm, mesoderm, and endoderm. Every organ and tissue will develop out of these three layers. The ectoderm will form the nervous system and backbone; the mesoderm will form the heart and circulatory system; and the endoderm will form the lungs, gastrointestinal tract, thyroid, liver and pancreas. The placenta has already begun to form, as well as the umbilical cord, which will deliver nutrients to -- and remove wastes from -- the growing embryo.

How Pregnancy Tests Work

In the first few weeks after conception, you may notice changes in your body and in the way you feel. A late menstrual period is usually the first pregnancy symptom. However, many other conditions, from stress to certain chronic illnesses, can delay the onset of menses, so a late period is not always a reliable sign until at least two weeks after the date you expect it.

On the other hand, you can have spotting while pregnant, so the presence of some bleeding doesn't eliminate the possibility of pregnancy.

In the first weeks of pregnancy, you may feel more fatigued than usual. You may experience nausea or vomiting, especially in the morning, a week or two after your missed period. Your breasts may have some tingling or tenderness and may even enlarge. The areolae (the dark areas around the nipples) may darken even more. If you have been having trouble getting pregnant and are recording your basal body temperature, the temperature may remain elevated. But just as with a late period, all of these signs and symptoms, if they occur at all, can have other causes. They do not prove you are pregnant.

If you go to see your doctor when your period is two weeks late, he or she may find physical changes that suggest you are pregnant. Your vagina and cervix may be blue to purplish because of increased blood flow. This is known as the Chadwick sign. The uterus may feel softer, larger, and more round.

Many women know they are pregnant before they see their doctor, however, because they perform a pregnancy test themselves at home. Nonprescription home pregnancy tests are available in any pharmacy and cost $10 to $20. These tests are designed to detect the presence in the urine of human chorionic gonadotropin (HCG), a hormone produced by the placenta shortly after fertilization.

Home pregnancy tests on the market today vary in sensitivity. Some can detect HCG one day after the missed period. Others require one to two weeks. Some tests must be done on a urine specimen obtained in the morning, when the concentration of HCG is the highest; others can be performed on a specimen collected anytime. Some tests react within one minute, but others require one to two hours. If you follow the directions carefully, the results are 90 to 95 percent accurate.

The tests are easy to perform. You immerse a trip of paper into a collected urine sample, or you urinate on a strip of paper. Positive tests usually are indicated by the formation of a lone or a plus sign on the paper. Now, there are even digital tests that display the results in a window so that there is no need to interpret lines or plus signs.

Even though these tests are extremely sensitive and accurate, it is possible to receive a false-positive or false-negative result. If you are taking fertility drugs, they may affect the outcome of the test and produce a false-positive result -- that is, the test result is positive even though the woman is not pregnant. However, more common than a false-positive test result is a false-negative one -- that is, the test result is negative even though the woman is pregnant. This usually occurs when the test is done too early after the missed period.

In some cases, the level of HCG is too low to detect, or the embryo hasn't become implanted yet. In approximately ten percent of women, the embryo implants after the first day of the missed period. Low levels of HCG may also be caused by an ectopic pregnancy (a pregnancy that develops outside the uterus). If the first test result is negative and your period doesn't start, repeat the test in five to ten days. If it is still negative, and you believe you may be pregnant, consult your doctor.

Your doctor will probably order a urine pregnancy test similar to the home pregnancy tests. If your doctor needs to know if you are pregnant at a time too early for the urine test to be used or if he or she suspects a false-negative test result, your doctor may order a blood test that is more sensitive and specific. Because it can measure very small amounts of HCG, your doctor can use it to diagnose pregnancy before a missed period (seven to nine days after fertilization) or to diagnose a tubal pregnancy (one that develops in one of the fallopian tubes). The test takes longer (two to three hours) to complete, and it is more expensive because it requires special equipment and personnel. Therefore, it is not used routinely to diagnose pregnancy.

When you finally know for sure that you are pregnant, your next question will undoubtedly be "When will my baby be born?" Delivery usually occurs 280 days after the first day of the last menstrual period. An easier way to calculate the delivery date, or due date, is to add nine months and seven days to the first day of your last normal menstrual period. Most women don't give birth on the exact date, but 80 percent give birth within ten days of this date -- either ten days before or ten days after.

As your pregnancy progresses, your doctor can double-check your due date with the timing of certain events. For example, the baby's heart is usually heard at 10 to 12 weeks. The level at which the top of the uterus can be palpated (felt) by the doctor is another clue; at 20 to 22 weeks, for example, it is usually at the umbilicus (navel). If your physician performs an ultrasound examination, the technician can measure the baby's head and compare the result with standard tables to estimate gestational age.

Discovering that you are pregnant is a thrilling moment. The next nine months will be filled with excitement both for you and your family.

Potty-Training Problems

Accidents happen, whatever method you use and however quickly your child learns. When one does, clean up quickly, making very little of it. Console your child if she is upset, and do not punish, scold, or shame her. If accidents are so frequent you can see training will be unsuccessful, stop at once and put your child back in diapers. Try again in a few weeks or a month, when you think the child is ready.

A child who is completely potty trained sometimes has accidents when she is ill. Sometimes a child regresses -- seems to forget entirely control of bowels or bladder or both. Regression sometimes accompanies or follows an illness.

A child who regresses (or one who can't seem to master the control training requires, though apparently ready) may have a lactose intolerance or other food intolerance or allergy or a urinary infection. The latter is usually accompanied by pain and a burning sensation when urinating and sometimes also by changed color or a foul odor in the urine. If you suspect a physical problem, consult your doctor.

In most cases, regression has an emotional, rather than a physical, cause. It may occur when a new baby comes into the house, when someone close to the family dies, when parents separate or divorce, or at some other stressful time. It's best to go along with it as best you can: Do not show anger or scold, but put your child back into diapers without comment.

Nighttime bladder control usually comes later than daytime control, although some children go through the night dry even before they are daytime-trained. Good control is needed because a child who sleeps through the night may have to wait as long as 12 hours. You may want to encourage nighttime control by holding back on liquids before bedtime and getting her up when you go to bed. Bed-wetting (enuresis) is considered a real problem only after a child is about six years of age.

Potty training is a major milestone in your child's life, but some parents can put too much pressure on the stage and make it harder on their child. If you follow our simple potty training advice, your child will be well on his way to independence.

How to Start Potty Training

The most common order for potty training is bowel control first, then daytime bladder control, and, later, nighttime bladder control, but all children do not follow that pattern. If your child has bowel movements at a regular time most days, you may have him trained in that department long before you try for bladder control; some parents try with good success when their children are about 18 to 24 months old.

A good time to try for a child who is not regular is about 30 minutes after a meal. Sit with your child for a few minutes, perhaps reading a book as you wait, but only as long as the child is willing. Be prepared for your child to feel proprietary about his feces, and be careful not to imply they are dirty or bad in any way. Some children are upset when their feces are flushed away, and some are frightened of the flushing noise. If your child is one of these, you may decide to flush only after he has left the bathroom.

One reason some children have trouble managing bowel control is that they are constipated. Constipation is not so much a matter of infrequency of bowel movements (having as few as three or four normal movements a week is perfectly natural for some children) as it is of hard stools that are painful and difficult for a child to pass. Discomfort makes a child hold back and compounds the problem. To help a constipated child, decrease his intake of milk and milk products and increase whole grain and dried fruit in his diet. Prune juice is helpful for a child who will drink it. If constipation continues, see your doctor for advice.

Summer is the best time to start potty training, if you have a choice, because the fewer clothes a child must bother with, the easier the process is. As often as you can, let your child wear underpants only to cut down the problems of dealing with outer pants or skirts and shirts.

You may find it helpful to plan to concentrate heavily on training for about a week, staying close to home with your child and not trying to accomplish much of anything else. The 24-hour method of training, advanced a few years ago by two psychologists, who designed it first to help persons with mental retardation (Nathan Azrin and Richard Foxx, Toilet Training in Less Than a Day), is championed by some parents and disapproved of by others. It involves very concentrated effort from both child and parent, and some believe it is overly manipulative and somewhat punitive. Potty training in one day may be too good to be true, as reports of the timing of success vary.

Your ultimate objective is to get your child to go into the bathroom alone when he needs to, pull down his pants, clean himself when finished, pull up his pants, empty the pot if one is used, and flush the toilet. Obviously, all this self-care does not occur at first, and you may help and remind your child to use the bathroom, and even lead your child physically to the bathroom for some time. The best times to give reminders or to take a child to the bathroom are when he first wakes in the morning, before and after naps, 30 minutes after meals, and before bed.

Children usually urinate about eight times a day and more often when they are excited or tired. Remember that part of potty training is teaching your child good habits of hygiene -- careful and thorough hand-washing and, for girls especially, wiping from front to back instead of the reverse (to prevent urinary tract infections).

When to Potty Train a Child

You will suspect your child is ready for potty training if wearing a wet or soiled diaper has become uncomfortable and distasteful to him or if he sometimes tells you or lets you know in some other way that urination or defecation is about to take place. Before you start, let the child observe you and any sibling in the bathroom; an older brother or sister is usually a great role model and an enthusiastic one. Get several pairs of underpants -- the looser, the better -- and let your child practice pulling them up and down. Look in your bookstore or library for some of the excellent potty-training books available for children, and read them to your child.

Decide whether your child will use a potty chair or the big toilet, with or without an adapter. The advantages of the potty chair are that it is childsize, close to the floor, and easy to get on and off. The adapter takes no extra space, doesn't need emptying, and allows your child to skip the middle step of changing from the chair to the big toilet. Simply teaching your child to use the big toilet is, of course, easiest of all, if the child is large enough and not frightened.

If you choose the potty chair, look for one in which the pot removes easily for emptying; you want your child to take over this task as soon as possible. If you opt for the seat adapter, consider one that folds up conveniently for travel. If your child is a boy, you need a shield, either built-in or attachable, to deflect the flow of urine because boys do not stand up to urinate at first. Do not use a chair or adapter that has a shield for a little girl; instances of injury to the labia have been reported. If you decide on the potty chair, set it up some time before you start training your child so it becomes familiar. Let the child sit on it, fully clothed, if he or she wishes, when you are in the bathroom together.

Another decision you must make concerns terminology. Children can handle the words for body parts easily enough, but the words urinate and defecate are more difficult, and they or substitutes for them will, of course, be used far more frequently. Most families settle on more casual words, such as pee and BM. Remember, there is a fine line between the acceptable and the crude; a word or term that sounds cute coming from a two year old may not be so at all from a five year old.

Still another decision to make regards rewards for successful performance during potty training. Parents disagree; some disapprove heartily of using material rewards for the accomplishment of what they see as a natural and normal step in development, while others see no harm in the practice and think it helps inspire a child to earlier success.

Among the latter, there are those who reward their children with treats, such as cookies, nuts, or raisins, and those who prefer to use small, inexpensive presents instead of food. One material gift all children get is a supply of "big girl" or "big boy" pants, often introduced with some fanfare by parents and usually thrilling to a child. Some parents who don't believe in any kind of concrete reward other than potty-training pants like to mark a child's progress with colored stars on a calendar.

All parents do agree that praise is a highly suitable and effective reward. Praise generously, they say, but not so lavishly your child begins to think of bowel and bladder control as earth-shaking achievements, more important than they really are and, possibly, as tools to manipulate their parents.

Hopefully now you've assessed that you and your child are ready to start potty training. In the next section, we will learn how to begin the process.

Potty-Training Overview

Potty training is a developmental skill your child cannot master until he is physically and mentally ready, however anxious you may be to have a "grown-up" child and be through with diapers. Actually, the process of potty training is perhaps more properly called potty learning, since your child teaches himself. Your part is to provide the setting and materials, a description of the methods used, and the necessary encouragement.

Among parents who keep close track of such events and brag a bit, the age at which their children were potty trained is almost as important as the age at which they slept through the night. Some studies show the average child is usually potty trained at about 30 months, but comparing your child with another is a waste of time; the differences among children in mastering this skill are vast. Girls are usually potty trained before boys of the same age, but a boy may be trained at age two and a girl not until age four.

The advantages of having a potty-trained child are obvious, and many parents consider starting training when their child is about the age of two, if the child seems ready. It's advisable to back off quickly, however, if your timing seems to be wrong. The self-esteem of a child who cannot yet succeed in this test of control suffers, and the anxiety engendered may lead to extended bed-wetting problems. In this article, we will answer your potty-training questions and offer you some potty-training tips over the following sections:

When to Potty Train a Child

There's a lot of debate around when you should potty train a child. Some parents take pride in having their child potty trained as soon as they possibly can. The truth is, pressuring your child to begin potty training before he is ready can only cause emotional pain and trauma that is completely unnecessary. In this section, we will show you how to read some of the signs that your child may be giving you that it is time to begin potty training.


How to Start Potty Training

Though your child might begin to display signs that he is ready to move on from diapers, this does not mean they are ready to embrace potty training. The concept might be strange or even scary to your child, and it is up to the parent to create an atmosphere that is encouraging and comfortable. On this page, we will offer some tips to make starting potty training easier. We will show when to begin toilet training, how you should arrange you time while training, and how you should prompt your child to go to the bathroom.


Potty-Training Problems

Potty-training accidents are bound to occur. Just like any of the new skills that your child will master over the years, toilet training takes patience and time. On this page, we will look at common potty-training problems and show you how to deal with them. Most accidents usually take place at night while the child is sleeping or when they are sick. However, in some cases, potty-training regression may have an emotional, instead of a physical, cause.

How to Prevent a Miscarriage

The first, and perhaps most important, step in a healthy pregnancy is getting prenatal care. This means finding an obstetrician right after a positive pregnancy test. The doctor will recommend prenatal vitamins, which are rich in many nutrients expectant mothers need, like calcium, iron and folic acid. Folic acid is especially important in the first few weeks of pregnancy, when the fetus is developing its neural tube, which eventually develops into the brain and spinal cord. A lack of folic acid during this period can result in birth defects. The recommended daily amount is 400 micrograms. There is enough folic acid in prenatal vitamins, and even in some multivitamins, but you can't get too much of it, so a healthy diet with foods rich in folic acid is recommended as well.

Between doctor's visits, pregnant women should follow a healthy diet, exercise on a regular basis, keep their "baby weight" within healthy limits, and try to manage stress levels. Many doctors believe that good health should begin before you even conceive in order to ensure the healthiest pregnancy possible. In fact, taking folic acid even before you get pregnant can help prevent birth defects.

­While there are plenty of vitamins and foods that you should ingest, there are a few things expectant mothers should avoid. They shouldn't smoke or even be around smoke. Either of these behaviors doubles the risk of placental problems and low birth weight. It also increases the risk of having a premature baby. However, there is good news. If a woman quits smoking during her first trimester, the risk returns to that of a woman who never smoked. Other things to avoid while pregnant include excessive amounts of caffeine, exposure to X-rays and, of course, contact sports or other dangerous physical activities.

It's also important for any woman who may suffer from a chronic health condition to take extra special care of herself. Women with high blood pressure should start checking their pressure at home and discussing medication changes with their doctors. Also, women with diabetes should check their blood sugar several times a day and adjust their insulin or oral medications as needed. Finally, pregnant women should treat any bacterial or viral infections. Some viral infections, like chlamydia or herpes, can determine if baby will be born vaginally or via Caesarean section.

Treating the Emotional Pain of a Miscarriage

A woman's physical health is important during and after a miscarriage, but her emotional health should not be ignored. The loss of a pregnancy can be felt just as strongly as a loss of a child. Women can also experience postpartum depression after a miscarriage. There is a wide variety of emotional treatments, including grief counseling, depression or anxiety medications, or simply opening up to friends and family. There are plenty of resources out there to help both the expectant mother and her partner.

Here are a few common tips for dealing with the loss of pregnancy:

Decide for yourself. Well-meaning friends and family will suggest ways to deal with your pain, but right after the miscarriage, don't do anything that makes you feel uncomfortable, such as returning baby clothes.
Take your time. There is no set time limit on how long you can grieve. As the cliché says, take it one day at a time and do things on your schedule.
Know your triggers. Seeing a baby, going to a baby shower or even walking past the Baby Gap could cause a swelling of emotion. It's OK to avoid these situations until you feel strong enough to handle them.

Postpone major decisions. When you're experiencing an especially emotional time, big decisions -- like buying a house, selling a car or changing your career -- should be delayed.

Don't cut your partner off. Keep the lines of communication open.
Set up a support network. While some friends and family may not understand the degree of your grief, and many are sure not to know what to say, they will all probably offer support. Many women also find comfort in going to support groups or joining an online chat group­.­

What Doesn't Cause a Miscarriage

There are many mixed signals out there about what may cause a miscarriage. Should women err on the side of safety and give up any type of physical activity, including sex? Happily, the answer is no. Here is a quick list of five things that DON’T cause miscarriage in uncomplicated pregnancies.­­

exercise
sex
working or lifting heavy objects
a minor fall or injury
stress

Miscarriage Treatment

Post-miscarriage treatment focuses on preventing further blood loss or infection. Of course, the goal of therapy is different for women who have suffered a threatened miscarriage. In these cases, prevention of further complications is key and may include bed rest or a reduction of activity.

Treatment depends on the type of miscarriage and when in the pregnancy it occurred. If it was early, additional treatment isn't usually required because all of the fetal tissue is usually expelled by the body. When a woman has suffered an incomplete or missed miscarriage, a procedure known as a dilation and curettage, or D&C, is performed to retrieve the tissues from the womb and stop any further bleeding or infection.

If a woman is in the process of having an inevitable miscarriage, she can have a D&C or wait and let the miscarriage occur naturally. She can choose the latter option if she was in the first trimester of pregnancy, has no signs of infection and has stable vital signs. Her body will usually expel the tissues within two weeks. Patients who prefer to miscarry this way should return to their doctor to confirm that all the tissues have been expelled. Another option is medication that helps the uterus expel the pregnancy, which usually works within a few days.

Even though a live birth has not taken place, women do need to receive certain medications after a miscarriage that relate to the fetus. For example, if the mother and the fetus have incompatible blood types, this could cause complication in any later pregnancies. If the mother is Rh factor negative, she will receive a shot called RhoGAM, which works to prevent any blood-type interaction between the woman and her miscarried pregnancy. This will protect a future fetus. If the mother doesn't get the shot, her Rh-negative blood can cross over to the fetus and cause complications. Antibiotics are also often used to reduce the chance of infection or to fight a current infection. Finally, the mother could require medication if she has been bleeding for a prolonged period -- and she should also be aware of symptoms of an infection, which can occur as late as six weeks after the miscarriage. These signs include fever, severe pain, heavy bleeding and chills.

After a miscarriage a women is usually encouraged to avoid putting anything in the vagina, like tampons or douches. Also, sex is discouraged immediately following a miscarriage. However, contraception, including IUDs, can be used again immediately, and a woman's period usually returns within four to six weeks. Studies are not clear on a safe waiting period between a miscarriage and a new pregnancy, but doctors usually advise waiting two to three months

Types of Miscarriage

Health care providers use the blanket term "miscarriage," so it may be surprising to learn that there are several different types.

Threatened: Sometimes a woman will experience vaginal bleeding in the early months of pregnancy. This bleeding is usually mild and may be accompanied by cramps or backaches. But the cervix remains closed and, as the name suggests, the miscarriage is not successful. In fact, the majority of pregnancies continue successfully after a threatened miscarriage.

Inevitable: This occurs when a woman experiences vaginal bleeding in conjunction with back or abdominal pain. In this type, the cervix is open, or dilated, and some of the uterine membranes may be ruptured. In these cases, the miscarriage has already begun.

Incomplete: An incomplete miscarriage results when only part of the pregnancy has been miscarried, leaving some products of conception in the womb. Symptoms often include heavier bleeding and severe abdominal pain after tissues have expelled from the womb. An ultrasound usually reveals the remaining tissue.

Complete: A complete miscarriage includes the expulsion of all products of conception, including the fetus and the placenta. While symptoms are similar to those seen in incomplete miscarriages, they subside quickly after the tissue is expelled. An ultrasound is often performed to ensure that no tissues remain and the womb is empty.

Missed: Basically, this is a miscarriage that the woman wasn't aware even happened. In these cases, there is embryonic death but the woman's body does not expel the tissues. So, cramping, bleeding and back aches are not present, and the only symptoms are loss of pregnancy symptoms such as nausea, weight gain and breast tenderness. These types of miscarriages are generally discovered when the fetal heartbeat isn't located during a routine doctor's visit.

Recurrent: Only about 1 percent of women have three or more first-trimester miscarriages.

Septic: A septic miscarriage can risk the health, and sometimes life, of the expectant mother. This type of miscarriage occurs as a result of either a missed or incomplete miscarriage. After the miscarriage, some or all of the remaining pregnancy tissue becomes infected. This tissue then infects the uterus, which can result in the spread of the infection throughout the body. Symptoms of this type of miscarriage can include vaginal bleeding, abdominal pain, fever, chills, exhaustion and a thick, foul-smelling vaginal discharge.

Miscarriage Warning Signs

There are often warning signs before a miscarriage actually occurs. It is important for pregnant women, as well as those planning to get pregnant, to know the most common of them.

Bleeding can range from mild to severe and can be brown or bright red in color. In some cases, women may have several bouts of bleeding. But it doesn't always mean that a miscarriage will soon follow. Up to 30 percent of all pregnancies involve some level of bleeding. In fact, studies have shown that as long as there is fetal cardiac activity, approximately 96 percent of pregnancies in which the mother experiences vaginal bleeding between seven and 11 weeks do not miscarry.

Mild to severe back pain and cramping is another common warning sign. The location of the cramps can vary widely and can be felt on one or both sides or in the middle of the abdomen. They usually occur in the lower abdomen but can move to the lower back.

Both mucus and clotlike vaginal discharge are symptoms of a miscarriage. The mucus is usually white to pink in color. Again, this is not necessarily a sign of inevitable miscarriage, but any tissue that passes through the vagina should be saved in a sterile container and brought to the doctor's office for examination.
Oftentimes, one of the first warning signs of a miscarriage is a decrease in pregnancy side effects. This can mean weight loss, absence of nausea or breasts that are no longer tender. A word of caution should be used here -- some of these symptoms, like weight loss in early pregnancy, may be normal for some women. But any woman experiencing these symptoms should consult her doctor.

Contractions are extreme pains that usually occur every five to 20 minutes.
If a woman does experience one of these symptoms, her doctor will usually perform an examination to determine how the pregnancy is progressing. This exam can consist of an internal pelvic examination, an ultrasound and blood tests. The internal exam is performed to establish if the cervix is dilated. If it isn't, the pregnancy usually continues. But if the cervix is dilated, a miscarriage is normally inevitable. An ultrasound can find a fetal heartbeat and assess if the fetus is developing normally. Finally, blood tests can determine if pregnancy hormones are still at the expected levels.

Causes of Miscarriage

A miscarriage doesn't necessarily mean that there's a problem with the mother's reproductive function. The most common -- and unpreventable -- cause of first-trimester miscarriage is an abnormality in the fetus's chromosomes. This is usually a result of a mishap in the division process or an abnormal egg or sperm cell. But a miscarriage that occurs in the second trimester of pregnancy is usually related to an issue in the mother's reproductive system. Remember, though, this is just a general rule.

Hormonal factors include illnesses that involve an imbalance in the mother's hormone levels. Such illnesses include Cushing's syndrome, thyroid disease and polycystic ovary syndrome.

Not surprisingly, a poorly controlled chronic condition can have adverse effects on a pregnancy. Conditions like diabetes, if they're not taken care of properly, can increase the risks of miscarriage and birth defects. High blood pressure, lupus and an underactive or overactive thyroid can also cause problems.

Certain acute infections can be passed to the fetus or placenta and also put the mother at risk. In developing countries, malaria is a main cause of miscarriages. In these areas, pregnant women are two to three times more likely to get malaria than nonpregnant women [source: ­MedScape]. Malaria can also cause low birth weight, premature delivery and stillbirth. In developing countries, common infections include walking pneumonia, rubella, chlamydia, gonorrhea, herpes and toxoplasmosis, which can acquired from being around cat feces.

Abnormalities in a woman's reproductive anatomy can also cause a miscarriage. For example, some women may have a septum (dividing membrane) that separates the uterus into sections. Because this septum has poor blood supply, the placenta will have trouble growing, depriving the embryo of nourishment. Lack of muscle tone at the cervix (the opening of the uterus into the vaginal canal) also makes a miscarriage more likely. Many women develop uterine fibroids. Although they're benign, a poorly placed fibroid -- like one that blocks the embryo's implantation and blood supply -- can cause a miscarriage.

Lifestyle factors are also an important factor. Smoking has been shown to increase the risk of miscarriage. And it doesn't have to be the mother's smoking -- one study focused on fathers who smoke. It found that if the father smokes 20 or more cigarettes a day, the mother's risk of miscarriage increases by 81 percent [source: American Journal of Epidemiology]. Alcohol consumption during pregnancy is also harmful. One study showed that a mother who drinks more than 30 ounces of alcohol a month doubles her miscarriage risk. Another study showed that women who have more than three drinks a week in the first trimester had an increased risk of miscarriage. It is important to note that it has not been determined how much alcohol is safe during a pregnancy, and most American doctors recommend complete abstinence. And not surprisingly, the use of illicit drugs greatly increases the chance of miscarriage and birth defects [source: UpToDate Patient Information].

Some (not as conclusive) studies have shown an increased risk of miscarriage in women who drink excessive amounts of caffeine. Many doctors recommend limiting caffeine intake to 200 milligrams or less per day, which equals about two cups of coffee.

It's just as important to consume the right things as it is to avoid the wrong things. Malnourished mothers also have an increased chance of miscarriage. Severly underweight women are often not healthy enough to get pregnant. And certain conditions that develop during pregnancy -- such as the rare illness hyperemesis gravidarum, which may result in severe malnutrition and dehydration -- can cause a woman to have excessive vomiting,

Finally, trauma can cause a miscarriage. It is important here to distinguish between physical trauma and emotional trauma. There is little proof that emotional trauma -- fear, grief, anger or stress -- results in an increased risk of miscarriage. However, physical trauma does greatly increase the risk. This includes surgeries that could possibly compromise the safety of the uterus. These types of procedures are usually performed only in emergency situations.

How Miscarriage Works

A miscarriage -- a pregnancy that ends spontaneously before the fetus can survive -- is an often devastating event. About 15 to 20 percent of recognized pregnancies end in miscarriage, but almost 75 percent of those are attributed to chemical pregnancy. This type of miscarriage occurs very soon after the egg has implanted into the uterus. It can go unnoticed because the resulting bleeding often occurs at the time of a woman's period, and she may not realize she had been pregnant at all.

Miscarriages usually occur within the first 13 weeks of pregnancy. While the chance of a miscarriage in all pregnancies is approximately 15 to 20 percent, studies show that once a fetal heart function has been noted, the chance of miscarriage falls to less than 5 percent [source: MedicineNet]. Unfortunately, the miscarriage rate can change with the mother's health and age. Women between 35 and 45 have a 20 to 35 percent chance of a miscarriage, while women over the age of 45 have a 50 percent chance. Having a miscarriage also increases your chance of having another, but only slightly. A woman under 35 who has had one previous miscarriage carries a 25 percent chance of having another one.

Other Assisted Reproductive Technology Treatments

IVF is only one of the assisted reproductive technology (ART) treatments. Here are some of the others:

Gamete intrafallopian transfer (GIFT)
This method is very similar to IVF, but the fertilization process takes place in the woman's fallopian tubes. The downsides are that it requires laparoscopic surgery and fertilization can't be visually confirmed like it is in IVF. Women with damaged fallopian tubes can't use this procedure, so they usually go with IVF. GIFT accounts for about 2 percent of all ART procedures in the United States [source: American Society for Reproductive Medicine].

Zygote intrafallopian transfer (ZIFT)
ZIFT procedures comprise a mere 1 percent of all ART cases in the United States [source: ASRM]. Fertilization takes place in the laboratory, and the embryo is transferred to the fallopian tube (not the uterus) using laparoscopy.

While neither GIFT nor ZIFT is as successful as IVF, they may be the first option for women who have tried other methods but whose infertility problems are not yet considered severe. Couples can try GIFT and ZIFT after six unsuccessful intrauterine insemination cycles. One advantage of GIFT is that the embryo isn't developed in the lab. This eliminates the moral dilemma of choosing how many embryos to transfer and how many to destroy. But ZIFT has a higher success rate because the egg is fertilized before being placed in the fallopian tube.

Intracytoplasmic sperm injection (ICSI)
ICSI is an adjunctive treatment used in more than 40 percent of all ART procedures [source: ASRM]. The use of ICSI is indicated when fertilization rates are expected to be lower than normal, usually because of problems with the sperm. ICSI is a micromanipulation technique -- ­doctors inject a single sperm into the egg to ensure fertilization.

Embryo cryopreservation
This process involves the freezing embryos for future use in IVF. Frozen embryos can be stored for many years, which allows couples to skip steps in future cycles, saving them money and cutting down on invasive procedures.

Risks of In Vitro Fertilization

The stages of IVF have different risks associated with them. During ovarian stimulation, women can get ovarian hyperstimulation syndrome (OHSS), which causes swollen, painful ovaries. Nearly 30 percent of IVF patients experience at least a mild case of OHSS. Mild cases can usually be treated with over-the-counter pain medication and a reduction in activity level -- OHSS generally resolves on its own in the absence of pregnancy. In moderate cases, which are less common, ovaries swell and fluid accumulates in the abdominal cavities. Symptoms of moderate OHSS include heartburn, gas, nausea, vomiting and loss of appetite. About 1 to 2 percent of women undergoing IVF develop severe OHSS, which may require hospitalization and involves sudden and excessive weight gain, severe abdominal pain with nausea or vomiting, and shortness of breath.

During egg retrieval, risk depends on the retrieval process. Transvaginal ultrasound aspiration carries a small risk of bleeding and infection and, sometimes, damage to surrounding structures like the bowel and bladder. The risks associated with laparoscopy include difficulty breathing, chest infection, allergic reactions to medications and nerve damage -- the same as with any surgery in which anesthesia is required.

When more than one embryo is transferred, there is always the risk of a multiple pregnancy. An infertile couple may take this as good news, but the presence of more than one embryo increases the risk to the embryos and to the mother. The most common is premature delivery. The babies could develop complications after birth or be born too early to survive. About 5 percent of IVF pregnancies are ectopic, which means that the fertilized egg develops outside the uterus, usually in the fallopian. This complication, unfortunately, requires immediate destruction of the fetus.

The In Vitro Process

The saying "nothing worth having comes easy" could refer to the process of trying to conceive via IVF. An IVF cycle takes four to six weeks to complete and usually costs about $12,000. Some women may have to endure multiple cycles before getting pregnant. In fact, in the United States, women under the age of 35 have only a 30 to 35 percent chance of having a baby after an IVF cycle, with the chance dropping to 20 to 25 percent in women between 35 and 40. Women over 40 have a 6 to 10 percent chance of a live birth per cycle of treatment

Ovarian stimulation. This step involves the use of ovulation, or fertility, drugs. These hormones, taken over a period of eight to 14 days, stimulate a woman's ovaries to produce several eggs per menstrual cycle instead of one. Successful IVF usually requires the fertilization of multiple eggs -- some may not fertilize or develop normally after fertilization. During this process, the physician will use ultrasounds or blood testing to determine when the eggs are ready for retrieval.

Egg retrieval. Once the eggs are deemed ready for retrieval, the doctor performs a transvaginal ultrasound aspiration. This is a simple surgical procedure that uses a small amount of anesthesia, such as a mild sedative. Once the ultrasound locates the mature follicles in the ovary, the doctor inserts a needle into the follicles and removes the eggs with suction. If the ultrasound can't find or access the ovaries, doctors might have to perform laparoscopic surgery. This technique -- in which doctors cut a small incision in the abdomen and locate the ovaries with a tiny fiber-optic lens -- is still simple and short, but it requires stronger anesthesia.

Insemination­. After retrieval, doctors examine the eggs and decide which of them hold the most potential for a successful pregnancy. They place these eggs in an IVF culture medium to await insemination. Meanwhile, they separate the father's sperm from his semen. The most motile sperm (the "best swimmers") are then added to the eggs in the incubator.

Fertilization and embryo culture. Usually within a matter of hours, a sperm cell penetrates an egg and fertilizes it. The following day, doctors visually confirm fertilization if they can see two pronuclei. These pronuclei are the basis of the embryo formation -- ­they will unite to form the nucleus of the zygote, which divides to become an embryo. A two- to four-cell embryo appears approximately two days after fertilization. On the third day, a six- to 10-cell embryo is seen. Five days after fertilization, the embryo can be called a blastocyst, which means it has formed a fluid cavity that results in the formation of fetal tissues and placenta. However, many embryos are not observed for this long. They can be placed in the uterus as early as one day and as late as six days after fertilization. In most cases, they're observed for two to three days to determine if the development is normal. ­

Embryo transfer. About two to three days after fertilization, the resulting embryo or embryos are transferred to the woman's uterus. Doctors suspend them­ in a drop of fluid and draw it into a transfer catheter -- a long, thin, flexible tube that has a syringe on one end. They then guide the catheter into the vagina, past the cervix and into the uterus. The patient is encouraged to remain in a resting position for an hour or two to prevent any stress on the body. If the embryo or embryos do attach to the uterine wall, a positive pregnancy test will result. ­

Coping With a Child Who Has a Hereditary Illness

Until two centuries ago, the death of a baby was an accepted, although tragic, risk of childbirth. Infectious diseases claimed many young lives. In mid-seventeenth century Europe, only one in four children survived to celebrate his fifth birthday. As recently as the late nineteenth century in the United States, one in five children died before the age of one year. Largely due to improved hygiene, immunizations, and antibiotics, babies in developed nations now die infrequently.

Although infant death is an uncommon occurrence, families sometimes have to cope with babies who have serious, chronic, and even fatal illnesses. Parents may walk an emotional tightrope between hope and despair for the long months that their child is ill.

Upon facing the diagnosis of serious illness in their infant or child, parents may at first feel nothing except shock and disbelief. Grief follows as a response to any loss. This loss may be the dissipation of their dreams of a healthy child. If the disease is expected to be fatal, parents may mourn in anticipation of the child's death. Despair, fear, anger, remorse, and loneliness are all emotions of the normal grieving reaction.

Dealing With Guilt

Guilt is another emotion many parents feel when they learn their infant is gravely ill. Parents can torment themselves or each other with feelings of responsibility for the illness. If the baby has a hereditary disease, feelings of self-blame may be especially overwhelming.

Self-reproach can be destructive. Negative feelings about oneself make it difficult for a parent to nurture the sick baby and the other members of the family. Guilt-ridden parents may either lavish excessive attention on the baby or turn away from her. Both responses amplify an older infant's or toddler's sense that something is wrong with her.

Parents may suffer further if communication between husband and wife is impaired. Their coping styles may be incompatible. Resentments may arise if one parent quits working to undertake the care of the sick child.

Sadly, having a child with a chronic or fatal disease can add enormous stress to a marriage. While it is safe to say that no marriage is the same after a child is diagnosed with a serious illness, families that recognize this stress are better equipped to cope. Marriage or family counseling is a vital part of coping with the stress, and your child's doctor or nurses can refer you to a therapist.

Helping Siblings to Cope

Parents often wonder whether their other children are too young to be told about the fatal illness or death of their sibling. Most psychologists feel it is crucial that the other children be told the truth in a straightforward manner that they can understand. Children who are not informed will still know something is frightfully wrong and may invent their own fantastic explanations.

A child's ability to comprehend death and dying depends on his age and prior experience with death (of a friend, family member, or pet). Before the age of two years, infants and toddlers are unable to grasp the concept of death. However, even very young children do react with distress to prolonged separations from loved ones.

After two years of age, given proper assistance from an adult, children are able to achieve a basic and concrete understanding of death. Still, they may have difficulty comprehending the permanence of death. Active imaginations lead to wild fantasies about where the deceased has gone. Because it is normal for children to have occasional negative feelings about their siblings, they may worry that their own thoughts or actions caused the illness. This sort of magical thinking and self-blame is especially common in children between the ages of five and eight.

A young child's response to the death of a sibling may be exasperating for parents. Using denial as a defense, he may act overtly as though nothing were wrong. Clues to inner turmoil include demanding, clinging behavior; regression to infantile behavior, such as lapses in toilet training; and increased aggression. Your warmth, understanding, and sharing of thoughts and feelings help him to grieve in a more appropriate fashion.

By 8 to 12 years of age, a child's understanding of death is similar to an adult's. However, the severe illness or death of a sibling may make him overly fearful of his own mortality.

Caring for Your Baby

As the family grapples with the serious illness and perhaps imminent death of the baby, the infant must also cope with the consequences of her ill health. An infant's need to be cuddled is just as great as her requirement for food. She thrives on consistent care from her parents. A baby quickly comes to know and love these special people.

Separations, such as during hospitalizations, can be very distressing for an infant. Parents of children with chronic diseases can sometimes arrange to care for the child at home with or without the assistance of a nurse. Should parents decide to bring their dying baby home, many communities have resources to assist them during this period (such as visiting nurses, home care nursing, and hospice care).

During necessary hospitalizations, most hospitals allow parents unrestricted visiting privileges and often provide facilities for parents to room-in with the child. This gives parents the opportunity to participate in the care of their sick baby. Caution must be exercised not to spend so much time with the ill child that the well-being of the parents and other family members suffers.

To help you cope with an ill or dying baby, do the following:

Tell the physician and other hospital staff about your needs and your baby's needs.


Provide the hospitalized baby with her favorite toys and food. Display pictures of the family where she can see them. The entire family should visit the baby as often as is feasible.


Obtain counseling with a skilled professional. Ask your doctor or contact the hospital for a referral.


Read about the subject. Most bookstores and libraries have many books for all age groups about coping with the illness or death of a loved one.


Search out support groups, which exist for many types of chronic illnesses of childhood. There are also support groups to help parents adjust to the death of an infant.


Allow siblings to visit the baby in the hospital.


Attending funeral services that are brief and not morbid help all family members to understand and accept the finality of their loss.


Keep lines of communication open between family members. Families that can share their feelings and console each other learn that even an enormous loss can be mastered.

However, it is important for new parents to keep in mind that this is the worst-case scenario. The overwhelming majority of children are born health or with only minor genetic fluctuations that are easily corrected. While it is a good idea to stay informed to all of the possibilities, there is also no reason to focus on the negative.

Genetic Diseases

There are several different categories of genetic diseases that are divided by the type of gene or chromosome that transmits the disease.

Autosomal Recessive Diseases

In most cases, a woman who inherits a defective recessive gene from one parent and a normal dominant gene from the other parent does not exhibit any symptoms of that illness but is a carrier of that abnormal gene. However, if she has children with a man who is also a carrier, their children have a 50 percent chance of inheriting one defective gene and being nonsymptomatic carriers, and a 25 percent chance of inheriting two defective recessive genes and expressing the disease. This pattern is called autosomal recessive inheritance. The better-known of these disorders include sickle cell anemia, Tay-Sachs disease, and cystic fibrosis.

Sickle cell anemia: Anemia is sometimes caused by a deficiency of hemoglobin. Hemoglobin is the substance in red blood cells that carries oxygen to the other cells in the body. In sickle cell disease, the hemoglobin is abnormal. People who carry only one defective recessive gene usually have no symptoms of the disease. People who inherit two sickle cell genes develop many problems due to the structure of their abnormal hemoglobin.

This defective hemoglobin molecule causes the normally round blood cell to sickle (assume a crescent shape). Anemia occurs because sickled red blood cells are more fragile, hence more easily destroyed. Sickled cells are also less able to bend as they squeeze through tiny blood vessels. Thus, these cells become trapped and obstruct small vessels.

Episodic clogging of the vessels with sickled blood cells causes tissue damage and pain, especially in the hands, feet, joints, and abdomen. Children with sickle cell anemia are prone to more frequent infections than children without the condition.

At present, no cure for sickle cell anemia exists. Treatment includes administration of painkillers and antibiotics as necessary. Children with sickle cell anemia who develop a fever should be seen by their doctor as soon as possible to determine treatment, which may include hospitalization for intravenous fluids and antibiotics. More children with sickle cell anemia are surviving into adulthood because of improved therapy and new, effective vaccines for many illnesses. Such vaccines are vital because children with sickle cell anemia are at increased risk for certain bacterial infections.

Because sickle cell anemia is most common among black persons, black adults are encouraged to undergo screening to determine if they are carriers of sickle cell anemia. Carriers can be identified by means of a simple blood test. Approximately eight percent of black people in the United States are carriers.

If both parents are carriers, they have a one in four chance of giving birth to a child with sickle cell disease. Sickle cell disease can be diagnosed before birth with the use of amniocentesis (see page 14 for an explanation of this procedure). In many states, most newborn babies are screened for sickle cell disease at birth by means of a blood test.

Tay-Sachs disease: Tay-Sachs disease is a metabolic disorder marked by the accumulation of a type of fatty acid in the liver, spleen, and brain. It is caused by a deficiency in the enzyme that normally degrades this fatty acid. After four to six months of normal development, children with Tay-Sachs exhibit deterioration in neurologic development. The disease progresses to mental retardation, blindness, and convulsions. Death usually occurs by age three or four. No treatment exists.

Preventive measures are available. The Ashkenazim, the Jews of eastern Europe, are disproportionately affected by Tay-Sachs, with nearly 100 times the rate of occurrence as other groups. Carriers have no symptoms of the disease and sometimes have no family history of the disease. It is recommended that all Jewish couples of eastern European descent undergo screening for the Tay-Sachs gene before they start their families. If both parents are carriers, diagnosis of Tay-Sachs disease in the baby can be made during pregnancy with the use of amniocentesis.

Cystic fibrosis: Cystic fibrosis is a serious childhood illness that causes the glands of the body to secrete abnormal sweat and mucus. The sweat glands secrete too much salt. The abnormally thick, sticky mucous secretions accumulate in and obstruct the lungs and pancreas. Since the pancreas is an important organ for digestion, these children fail to grow properly. The thick mucus in the lungs makes breathing difficult and leads to infections. Death is usually due to respiratory failure. Although no cure exists, improved treatment has brightened the prognosis of children with cystic fibrosis, giving them a good chance for survival into adulthood.

Cystic fibrosis is much more common in white people of northern European extraction. In the United States, approximately 1 in 29 white people are carriers. One infant in every 3,000 live births has cystic fibrosis. Traditionally, the disease has been diagnosed on the basis of sweat test results obtained only after the appearance of the symptoms. However, now diagnosis can be made before birth with amniocentesis.

Phenylketonuria: Phenylketonuria (PKU) is a rare disorder that can cause severe mental retardation. It is caused by an inability to convert an amino acid called phenylalanine into another amino acid called tyrosine. (Amino acids are the building blocks of proteins.) At elevated levels, phenylalanine damages brain cells, causing retardation.

In the United States, all newborns are screened for PKU by means of a blood test. Early detection and prompt treatment can prevent the mental retardation. Treatment consists of limiting a child's dietary intake of phenylalanine. If this dietary regimen is followed, children with PKU can have essentially normal development. Pregnant women who have PKU need to stick to this special diet to protect the baby's developing nervous system. All people with PKU must completely avoid the artificial sweetener aspartame, which contains phenylalanine. New research is in progress to help identify carriers of PKU and to diagnose PKU prenatally.

Autosomal Dominant Diseases

Another category of hereditary disease is called autosomal dominant disease. Because the defective gene is dominant, the disease is expressed even if only one gene is defective. A normal gene cannot mask the harmful effects of an abnormal gene as it can in autosomal recessive disease. If one parent has an autosomal dominant disease, the chances are 50 percent that each child will inherit the disorder.

Huntington chorea: An example of an autosomal dominant disease is Huntington chorea, a brain disease marked by abnormal body movements and mental deterioration beginning in middle age.

Although a few medicines have been found to make the symptoms more tolerable, the disease has no cure. Researchers have been able to identify carriers in families with Huntington chorea with a genetic test. It is hoped this procedure will be perfected and also extended to prenatal diagnosis.

Sex Chromosomes and Sex Determination

As previously stated, most cells in the body have 46 chromosomes, consisting of 22 pairs of autosomes and 2 sex chromosomes. The sex chromosomes determine whether a person is male or female. Women have two X chromosomes. Men have one X and one Y chromosome.

The sex cells (eggs and sperm) contain only 23 chromosomes -- 22 autosomes and 1 sex chromosome. Each ovum (egg) contains one X chromosome. Half of a man's sperm cells carry an X chromosome; the other half carry a Y chromosome. During fertilization, the genetic material of the egg and sperm unite to create the full complement of 46 chromosomes. If the ovum is fertilized by a Y sperm, the baby will be a boy; fertilization by an X sperm results in a girl.

X-Linked Recessive Diseases

In sex-linked inheritance, the gene responsible for the disease is located on the X chromosome. Usually, the abnormal gene is recessive. For these reasons, the resultant disorder is called an X-linked recessive disease. In a woman with such a defective gene, the effects of the abnormal gene are masked by those of the normal gene on the other X chromosome. Although she does not have the disease herself, she is a carrier, capable of transmitting the defective gene to her children.

In X-linked recessive disease, the Y chromosome lacks the corresponding normal gene to mask the harmful effects of the abnormal gene on the X chromosome. Thus, all male offspring of a woman who is a carrier of an X-linked recessive disease have a 50 percent chance of having the condition. All female offspring have a 50 percent chance of being carriers. Following are examples of X-linked recessive disorders:

Color blindness: A person with the most common form of color blindness cannot distinguish red from green hues.

Hemophilia: In hemophilia, the blood does not clot properly. Persons with hemophilia bleed excessively, even from minor cuts. There are several forms of hemophilia, each caused by a deficiency of a different protein called a clotting factor. The disease is managed by giving transfusions of the deficient clotting factor and of whole blood to replace blood losses. Research continues toward the accurate identification of carriers and prenatal diagnosis of this disease.

Duchenne muscular dystrophy: Muscular dystrophy refers to a group of rare diseases characterized by progressive muscular weakness. Duchenne type muscular dystrophy is the most common. Between the ages of two and six years of age, children with this condition develop weakness first in their legs, then in their arms and trunk. The weakness rapidly worsens. Most children die during their second decade, usually as a result of severe weakness of the muscles of respiration. The disease has no cure. Treatment includes physical therapy, braces, and, occasionally, surgery.

Newer techniques and better understanding of the genes involved have made prenatal testing possible. Advances in genetic testing are soon likely to make it possible to detect the recessive trait in carriers as well.

Multifactorial Genetic Diseases

Multifactorial genetic diseases are illnesses that tend to run in families. These diseases are not due simply to the inheritance of a single defective gene. Rather, a cluster of faulty genes is inherited, which predisposes the person to a disease. Given the appropriate environmental factors, the person may actually develop that disease. Examples of illnesses that run in families include such chronic adult diseases as coronary heart disease, high blood pressure, and stomach ulcers, as well as birth defects, such as cleft lip and palate and spina bifida.

Cleft lip and palate: In cleft lip, the upper lip is divided by a vertical fissure. In cleft palate, the roof of the mouth is split by a longitudinal fissure. These two birth defects can occur alone or together. They are the result of incomplete fusion of the components that form the lip and mouth during fetal development.

Spina bifida: Spina bifida is a failure in the closure of the bony vertebral column with or without protrusion of the nerve tissue of the spinal cord. Paralysis below the defect often accompanies spina bifida if the spinal cord does protrude. When the spinal cord does not protrude, the vertebral defect may go unnoticed. Clues to indicate the presence of this form of spina bifida are abnormalities of the skin and tufts of hair overlying the spine in the lower part of the back.

During pregnancy, spina bifida in the fetus can be diagnosed by means of ultrasound study and detection of elevated levels of a substance called alpha-fetoprotein in the mother's blood and in the amniotic fluid that bathes the fetus. Spina bifida can be caused by a folate deficiency in the mother during pregnancy or exposure of the pregnant woman to certain drugs that interfere with folate.

Chromosomal Abnormalities

Sometimes the structure or the number of chromosomes is not normal. The risk of having a child with chromosomal abnormalities increases with increasing maternal age (and to some extent with increasing paternal age as well). If chromosomal abnormalities occur in the sex cells (eggs and sperm), the offspring may have physical and mental disorders.

Down syndrome: Formerly called mongolism, Down syndrome is a condition caused by a chromosomal abnormality. Due to the failure of the chromosomes to divide evenly during cell division, the person with Down syndrome has an extra chromosome (a total of 47). The presence of this extra chromosome causes a characteristic physical appearance and delayed physical and mental development. Other ailments, such as defects in the heart and digestive system, can accompany this syndrome. Despite their disabilities, children with Down syndrome usually have pleasant dispositions and can do quite well if given special therapy.

The cause of the chromosomal abnormality leading to Down syndrome is unknown. A genetic predisposition may exist. The incidence of Down syndrome increases with increasing maternal age. The condition can be diagnosed prenatally with the use of amniocentesis. For these reasons, women who have previously given birth to a baby with a chromosomal abnormality or who are older than 35 years of age are encouraged to undergo amniocentesis.

Genetic Counseling

In recent years, tremendous progress has been made in the development of genetic tests to diagnose heritable diseases. You may wish to consult your physician about genetic counseling if any of the following risk factors apply to you:

You have a family history of a hereditary disease or of mental retardation of unknown origin.


You are a woman older than 35 years of age.


You have had a previous child with a chromosomal or other genetic disorder or any birth defects.


You have had three or more miscarriages or a stillbirth.
If you have any concerns or questions regarding heritable diseases, ask your physician. If you are considered to be at risk for passing on a hereditary disease to your children, you can receive genetic counseling. A genetic counselor asks you about your personal and family medical history. Blood tests may be necessary to help determine whether you are a carrier of a heritable disorder. You are advised about the chances of transmitting hereditary illness to your offspring.

If you are pregnant, the well-being of your fetus can be assessed by several procedures:

Ultrasound: High-frequency sound waves are used to produce images of the placenta and fetus. It can detect gross defects, especially of the heart, bones, brain, and spinal cord.


Amniocentesis: A small amount of amniotic fluid, the liquid that bathes the baby inside the uterus, is withdrawn and analyzed. Many genetic diseases can be diagnosed prenatally with the use of am-niocentesis.


Chorionic Villus Sampling (CVS): A few fetal cells from the chorionic villus, a part of the placenta, are withdrawn and analyzed for the presence of select diseases.


Fetoscopy: The fetus is directly observed within the uterus by means of special lenses. During fetoscopy, fetal blood can be sampled. It is rarely used today.


Radiography: X-ray films are occasionally obtained because they can depict certain skeletal abnormalities in the fetus.
Remember that the diseases described in this section are rare. Most expectant parents can look forward to the arrival of a healthy baby. If you are pregnant or hope to be and have any worries about the well-being of your child, don't hesitate to address them with your doctor.

If your child does have a hereditary disease, however, it's important to confront and accept the realities of this challenge. Keep the lines of communication open within your family, seek out support groups, and avoid bearing all the guilt for your child's disease.