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.

Dilation and Curettage

Dilation and curettage, also called a D&C, is a surgical procedure in which the cervix of the uterus is dilated (expanded) and the endometrial lining of the uterus is scraped with a curette (a loop-, ring-, or scoop-shaped instrument with a long handle).

Purpose

This procedure is often used in the diagnosis of diseases of the uterus (such as cancer) and to halt excessive bleeding. It is also used to perform an abortion and may be employed after a miscarriage (involuntary expulsion of a fetus before it is able to live on its own) to remove any remains of tissue and thereby lower the risk of hemorrhage and infection.

Dilation alone may be performed to enlarge the passageway out of the uterus. This might be done if a severely narrowed cervix is causing painful menstruation because of restricted flow of menstrual fluid. For treatment of this problem, multiple dilations may be necessary since the cervix will often become narrow again after several months.

The Procedure

A D&C is a relatively minor procedure, seldom requiring hospital admission. Because the rectum should be empty before the procedure, an enema may be given; the urinary bladder should also be emptied.

The procedure is performed in an operating room under sterile conditions. Anesthesia may be general (the patient is put to sleep) or local. The patient rests on her back with her feet in stirrups. The surgeon inserts metal dilators of progressively larger sizes into the cervix until it is open enough to permit the insertion of the surgical instruments.

A curette is used to remove endometrial tissue. Special forceps may also be used to remove tissue. When the operation is finished, an absorbent pad is placed over the entrance to the vagina. The pad is checked every 15 minutes for two hours, and excessive bleeding is reported to the physician.

Mild painkillers should be enough to control discomfort from the operation. If there is pain in the abdomen that cannot be relieved in this way or that is continuous or sharp, it should be reported immediately. Some difficulty in urinating is to be expected immediately after the procedure.

In most cases, the patient stays in bed for one to two hours after surgery. Most women return home several hours after the procedure or the next day. A return to many daily activities is possible immediately, and in a week all normal physical activities may be resumed. Sexual intercourse and use of tampons are not recommended, however, until after the follow-up visit to the doctor (usually about two weeks after the procedure).

Risks

The principal risks of a D&C are hemorrhage, infection, and perforation (puncture) of the uterus. The latter is more likely during pregnancy, when the uterine walls are especially soft and thin.

Psychosomatic Conditions

Couvade syndrome is currently not a recognized medical condition, although the St. George's University study gave credibility to its existence. It seems logical that the syndrome can be explained as a reaction by the body to an emotional state in the mind. The next step is to find this link between mind and body, but so far, this link has proven rather elusive.

It wasn't until the 18th century that the investigation into the mind's effects on physical illness began in earnest. European physicians looking into female hysteria (which had previously been thought to originate in the uterus), came to believe that it was a medical condition that could be explained as a reaction to a highly charged emotional state. Since then, the intensity of the investigation into psychosomatic conditions has waxed and waned, although it has never been abandoned.

Psychosomatic conditions may manifest in different ways. For example, it may be looked upon as strictly a mental disorder, as in the case of a patient with Munchausen syndrome, in which a person is convinced that he or she is sick in order to gain attention. While the symptoms are strictly in the patient's mind, they may feel quite real to him or her. It can also manifest as the result of fear or anxiety, as in conversion disorder, a mental condition in which emotional distress manifests itself physically, as in a dancer who is afraid to go on stage developing paralysis [source: Mayo Clinic].

But there is also another way of looking at psychosomatic conditions that don't infer a type of mental illness. It is becoming widely accepted in medicine that the mind has a large influence on the health of an individual.

In this sense, psychosomatic conditions can be as simple as stress causing a headache or as complex as an introverted personality contributing to the development of cancer. Voluminous studies have shown a correlation between illness and emotion. One study found that people diagnosed with panic disorder display a higher likelihood for abnormal electrical activity in their heart function. Others have shown that people who suffer from depression following major surgery are more likely to die than those with a positive attitude following the same types of surgery.

But as the research on the correlation between emotional states and physical illness accumulates, the actual links are still being investigated. Like Couvade syndrome, it's evident: The mind affects the body. But science has never been a discipline to be satisfied with mere correlation.

Endocrinology may be the best contender in providing the link between body and mind. Scientists have known for a long time that hormones play a role in both mood and physiology. For example, emotional distress has been shown to have a correlation to the release of the hormone 17-OHCS by the adrenal gland. The possible connection here may be that emotional stress, like anxiety, acts on the central nervous system -- which can influence the functioning of the endocrine system.

As science delves more deeply into the influence of emotion over physiology, the connection between mind and body is becoming increasingly apparent. This connection seems to go both ways: Like the effect emotion can have on glands, other studies have found that electrolytes -- elements such as potassium that create the electrical impulses need for body function -- are correlated to mental illnesses, like depression. Perhaps eventually research like this will yield an explanation for sympathetic pregnancy.

Can I feel pregnant when my wife is?

Men are usually somewhat peripheral during pregnancy. After all, women are the ones who carry the child and endure the process of labor and childbirth. Most men will take advantage of any opportunity to help, and getting up in the middle of the night to head to a drive-thru for french fries and a chocolate shake is often their greatest expression of sympathy for their wives' condition. But for some men, doting is just the beginning.

Imagine your stomach bloating as your wife's grows, or the two of you ill at the same time with morning sickness. Up until recently, the medical establishment has ignored reports of fathers-to-be suffering everything from strange food cravings to backaches and weight gain. But a study in the summer of 2007 went a long way to proving the existence of Couvade syndrome -- or sympathetic pregnancy.

The study conducted at St. George's Hospital, a part of St. George's University in London, England, examined 282 men ages 19 to 55 whose wives were pregnant. A group of 281 men whose wives were not pregnant was used as a control in the study. Researchers found that the majority of the men with pregnant wives displayed a variety of pregnancy-associated symptoms like mood swings and morning sickness.

Stomach cramps were the most commonly reported; one man reported his own labor pains that rivaled his wife's while she was delivering their baby. A few of the men who showed signs of sympathetic pregnancy developed pseudocyesis -- a phantom swollen stomach.

The study found that the symptoms generally followed a similar pattern to the men's wives' pregnancies. The symptoms came on during the early stages of the pregnancy, reached their worst point within the third trimester and cleared up after the wives had given birth. Even more strangely, 11 of the men who sought medical help for their symptoms found that doctors could offer no physical explanation.

Cases of Couvade syndrome (which comes from the French "couver," meaning "to hatch") have been widely documented in different parts of the world. One 1994 study showed that some Thai men also exhibited symptoms of sympathetic pregnancy. Another study, conducted in Italy the following year, says that reports of the incidence of sympathetic pregnancy ranges from 11 to 65 percent [source: Klein]. What's more, a person needn't be a man with a pregnant wife ­to experience Couvade syndrome. In at least one case documented in the United States, a woman began to show sympathetic symptoms similar to her pregnant twin sister who lived in another city [source: Budur, et al].

But why does it happen? Researchers aren't sure. There are, however, a wide variety of suggestions. It may be a man's anxiety over the impending birth of his child that could cause him to show signs of sympathetic pregnancy. Another theory is that Couvade syndrome may be a man's "statement of paternity" or even a sign of envy toward his wife or feelings of rivalry with the baby

Chocolate in pregnancy keeps baby happy

Expectant mothers can take heart this Easter. Tucking into chocolate eggs is good for the baby, according to a study of over 300 women - especially if you are feeling a bit on edge.

Katri Raikkonen at the University of Helsinki, Finland, and her colleagues asked pregnant women to rate their stress levels and chocolate consumption.

After the babies were born, they looked for an association between the amount of chocolate their mothers had eaten and the babies' behaviour. Six months after birth, the researchers asked mothers to rate their infants' behaviour in various categories, including fear, soothability, smiling and laughter.

The babies born to women who had been eating chocolate daily during pregnancy were more active and "positively reactive" - a measure that encompasses traits such as smiling and laughter.

And the babies of stressed women who had regularly consumed chocolate showed less fear of new situations than babies of stressed women who abstained.

The researchers point out that they cannot rule out the possibility that chocolate consumption and baby behaviour are both linked with some other factor.

But they speculate that the effects they observed could result from chemicals in chocolate associated with positive mood being passed on to the baby in the womb.