IN THIS CHAPTER
Taking a look at your baby’s development
Looking — and feeling — like you’re going to have a baby
Heading to prenatal visits
Knowing when to be concerned
The second trimester, which encompasses the three months between weeks 13 and 26, is often the most enjoyable part of pregnancy. The feelings of nausea and fatigue so common during the first trimester are usually gone, and you feel more energetic and comfortable. The second trimester is a very exciting time because you can feel the baby moving within you and you’re finally starting to show. During the second trimester, blood tests, prenatal tests, and ultrasound (sonogram) can confirm that the baby is healthy and growing normally. And many women find they can finally grasp the concept that they’ll soon be having a baby. The second trimester is often the time you start sharing the exciting news with family, friends, and coworkers.
Following Your Baby’s Development
Your baby grows rapidly during the second trimester, as you can see in Figure 2-1. The fetus measures about 3 inches (8 centimeters) long at 13 weeks. By 26 weeks, she’s about 14 inches (35 centimeters) and weighs about 2¼ pounds (1,022 grams). Somewhere between weeks 14 and 16, the limbs begin to elongate and start to look like arms and legs. Coordinated arm and leg movements are observable on ultrasound, too. Between 18 and 22 weeks, you may begin to feel fetal movements, although they don’t necessarily occur regularly throughout the day.
Illustration by Kathryn Born, MA
FIGURE 2-1: During the second trimester (13 to 26 weeks), your baby grows and develops at an astounding rate.
The baby’s head, which was large in relation to the body during the first trimester, becomes more proportional as the body catches up. The bones solidify and are recognizable on ultrasound. Early in the second trimester, the fetus looks something like an alien (think E.T.), but by 26 weeks, she looks much more like a human baby.
The fetus also performs many recognizable activities. She not only moves but also undergoes regular periods of sleeping and wakefulness and can hear and swallow. Lung development increases markedly between 20 and 25 weeks. By 24 weeks, lung cells begin to secrete surfactant, a chemical substance that enables the lungs to stay expanded. Between 26 and 28 weeks, the eyes — which had been fused shut — open, and hair (called lanugo) appears on the head and body. Fat deposits form under the skin, and the central nervous system matures dramatically.
At 23 to 24 weeks, the fetus is considered viable, which means that if she were born at this time, she would have a chance of surviving in a center with a neonatal unit experienced in caring for very premature babies. A premature baby born at 28 weeks (nearly three months early) and cared for in an intensive care unit has an excellent chance of survival.
Most mothers begin to feel their babies move at about this time. Knowing for sure when you first feel your baby moving inside you is difficult. Many women sense fluttering movements (called quickening) at about 16 to 20 weeks. Not every woman can tell that sensation is actually the baby moving. Some think it’s just gas (and maybe you did eat too much chili), but most likely, it’s the baby. Around 20 to 22 weeks, the fetal movements are much easier to identify, but they still aren’t consistent. Over the course of the next four weeks, they fall into a more regular pattern.
Different babies have different movement patterns. You may notice your baby tends to move more at night — perhaps to prepare you for all the sleepless nights you’ll have after she’s born! Or you may simply be more aware of the baby’s movements at night because you’re more sedentary at that time. If this is your second (or third or fourth …) child, you may start to feel movements a couple of weeks earlier.
Just because you haven’t felt your baby move at all by 22 weeks doesn’t mean you need to worry. A common explanation for not feeling the baby’s movements is that the placenta is implanted on the anterior (front) wall of the uterus between the baby and your skin. The placenta acts as a cushion and delays the time when you first feel movements. Just let your practitioner know. He may recommend an ultrasound, especially if you haven’t had one already, to check the baby.
After 26 to 28 weeks, if you stop feeling the baby move as much as usual, call your practitioner. By 28 weeks, you should feel movement at least six times an hour after you eat dinner. If you aren’t sure whether the baby is moving normally, lie down on your left side and count the movements. If the baby moves — any movement counts — at least six times in an hour, be reassured that the baby is okay. On the other hand, if you feel that the baby’s movements are still less than they should be, call your practitioner.
CLOTHING YOURSELF IN MATERNITY GARB
Thank goodness the fashion industry has recognized that women continue to care about looking chic and professional when they’re pregnant — which doesn’t necessarily mean wearing those choir-boy blouses with big bows at the neck. Many women look forward to shopping for maternity clothes, while others aim to stay in their usual clothes for as long as possible. Keep in mind that you’re going to need maternity clothes only for a few months, and they’re not cheap. So don’t be shy about accepting hand-me-downs (your friends are probably happy to see their clothes get more use) and check out consignment shops, secondhand stores, and garage sales, where you can often buy inexpensive, gently used maternity clothes. Or forgo maternity clothes altogether: You can often go a long way through your pregnancy in regular leggings and big shirts or sweaters.
Perhaps the most important items to buy are comfortable shoes and roomier bras. Both shoe size and bra size can increase during pregnancy. (And you don’t have to wear special maternity underwear — unless you find it especially comfortable. Many kinds of regular underwear, especially the bikini kind, fit well under a bulging belly.)
Understanding Your Changing Body
By 12 weeks, your uterus begins to rise out of your pelvis. Your practitioner can feel the top of the uterus through your abdominal wall. By 20 weeks, the top of your uterus reaches the level of your navel. Then each week, your uterus grows by about 1 centimeter (½ inch). Your doctor may run a tape measure from your pubic bone to the top of your uterus to measure the fundal height (see Book 1, Chapter 2) to see that your uterus and the baby are growing appropriately. Many women begin to show at 16 weeks, although looking pregnant varies a great deal. Some women look pregnant at 12 weeks; others aren’t obvious until 28 weeks.
Many of the changes you experience have little to do with your belly’s size. Rather, they involve your baby’s development and your body’s continuing adaptation to pregnancy. You may experience some, none, or all of the symptoms in this section.
FOR PARTNERS: WATCHING MOM GROW
“Honey, do you think I’m fat and ugly now?” You may start to hear this question during the second trimester when the mother’s body really begins to change. Tread lightly when making comments about your partner’s belly size. Maybe you’re just being observant, but it’s a great way to get the cold shoulder without intending it! Here’s a tip: It’s not a multiple-choice question. You have only one answer, and you may as well commit it to memory so that you can answer without hesitation: “Absolutely not, honey. You’re the most beautiful woman I’ve ever laid eyes on.”
Enjoy the second trimester. Often, it’s the most fun part of pregnancy for both parents. Morning sickness fades away, fatigue subsides, and your partner begins to feel the baby move around inside her. Often, you, too, can feel the baby move by placing your hand on the mom’s abdomen.
During this trimester, many mothers get an ultrasound exam to check the baby’s anatomy. Try to go along to see the ultrasound exam; it’s one of the most enjoyable prenatal tests. You get to see the baby’s hands, feet, and face, and you get to watch the baby move around. For the first time, you see the living, moving, growing little human inside, and suddenly the whole enterprise seems so much more real!
By the end of the second trimester, you may begin prenatal classes. Don’t make excuses! Go with your partner. The classes are designed for both the partner and mother. During this time, you can find out how to be useful during labor and delivery. And you can also ask questions about what to anticipate — to relieve some of your own anxiety.
Forgetfulness and clumsiness
You may have heard that misplacing keys, bumping into furniture, and dropping things are side effects of pregnancy. Although there seems to be no medical explanation for these effects, some women do feel they’re more scatterbrained and clumsy. If it happens to you, don’t worry. You’re not losing your mind. Look at it this way: Now you have an excuse for having forgotten your best friend’s birthday. And rest assured you’ll go back to being your brilliant, coordinated self after your baby is born.
Gas
You may find that you develop the annoying and embarrassing tendency to burp and pass gas at inopportune times during this trimester. If it’s any consolation, you’re not the first pregnant woman to run into this problem. Unfortunately, though, you can do very little about it — besides getting a dog to blame it on. Try to avoid becoming constipated (see Book 2, Chapter 1) because that can make things worse. Also avoid eating large meals that may leave you feeling bloated and uncomfortable or foods that you know make the problem even worse.
Hair and nail growth
While you’re pregnant, your fingernails and toenails may become stronger than they’ve ever been before and grow at an unprecedented rate. Manicures are safe when done in a reputable, clean salon, and they often relieve stress, so sit back and enjoy your beautiful nails!
Pregnancy also speeds up hair growth. Unfortunately, some women find hair also begins growing in unusual places — on their face or stomach, for example. Waxing, plucking, or shaving the unwanted hair is safe, but hair removal creams (depilatories) contain chemicals that haven’t been extensively studied. Because safer alternatives are readily available, avoid these creams. Take comfort in the likelihood that the unwanted hair will disappear after your baby is born.
Heartburn
Heartburn — the burning sensation you feel when stomach acids rise into your esophagus — is common during pregnancy. Heartburn has two basic causes (neither of which validates the myth that heartburn means your baby will have a lot of hair):
· The high level of progesterone your body is producing can slow digestion and relax the sphincter muscle between the esophagus and the stomach, which normally prevents the upward movement of stomach acids.
· As the uterus grows, it presses upward on the stomach, which can push stomach acids into the esophagus.
For tips on how to avoid or manage heartburn, refer to Book 1, Chapter 4. And if it becomes intolerable, talk to your doctor about taking a prescription treatment. Many effective heartburn treatments are considered safe for use during pregnancy. The use of famotidine (Pepcid), ranitidine (Zantac), and omeprazole (Prilosec/Nexium) in the first trimester has been studied, and researchers found no increased risk for birth defects, preterm labor, or problems with fetal growth. (The first trimester is the period of greatest risk, so medications proven safe for use in the first trimester are presumably safe in the second trimester, too.)
Lower abdominal/groin pain
Between 18 and 24 weeks, you may feel a sharp pain or a dull ache near your groin on either or both sides. When you move quickly or stand, you may notice it worsen, and it may fade if you lie down. This pain is called round ligament pain. The round ligaments are bands of fibrous tissue on each side of the uterus that attach the top of the uterus to the labia. The pain occurs because as the uterus grows, the ligaments stretch. The pain can be quite uncomfortable and sometimes can stop you in your tracks, but it’s normal. The good news is that it usually goes away — or at least lessens considerably — after 24 weeks.
Sometime in the middle of the second trimester (the exact time varies), you may start to feel mild, short-lived contractions or cramps. These are referred to as Braxton-Hicks contractions and are nothing to worry about. They often are more noticeable when you’re walking or physically active and then go away when you get off your feet. If they become uncomfortable and regular (more than six in an hour), call your practitioner.
Nasal congestion
The increased blood flow that occurs during pregnancy can cause stuffiness and some swelling of the mucous membranes inside your nose. This, in turn, can lead to postnasal drip and, ultimately, a chronic cough. Nasal saline drops may provide some relief and are perfectly safe to use during pregnancy. Keeping the air in your home or office well humidified also helps. Nasal sprays and decongestants work, too, but avoid using these medications for more than a few days at a time.
You (or your partner, especially) may notice that suddenly you’re snoring like never before! This common symptom again relates to the increase in nasal congestion. To treat this? Lovingly suggest that your partner buy a good set of earplugs!
Nosebleeds and bleeding gums
Because of the higher volume of blood coursing through your body to support your pregnancy, you may experience some bleeding from small blood vessels in your nose and gums. This bleeding usually stops by itself, but you can help by applying slight pressure to the point of bleeding. If bleeding becomes particularly heavy or frequent, call your doctor.
Using a softer toothbrush may help minimize bleeding when you brush your teeth.
Skin changes
The hormones coursing through your body at soaring levels may make strange things happen to your skin. These changes, illustrated in Figure 2-2, don’t occur in all women, and if they do happen to you, rest assured they usually fade away after the baby is born.
· You may notice a dark line, called the linea nigra, on your lower abdomen running from your pubic bone up to your navel. This line may be more noticeable in women with relatively dark skin. Fair-skinned women often don’t develop this line at all.
· The skin on your face may darken in a masklike distribution around your cheeks, nose, and eyes. This darkening is called chloasma or the mask of pregnancy. Sun exposure makes it even darker. Use a facial cream with sunblock to minimize the effects of the sun on chloasma.
· Red spots, called spider angiomas, may suddenly appear anywhere on your body. Press on them, and they probably turn white. These spots are concentrations of blood vessels caused by the high level of estrogen in your body. They’ll probably disappear after delivery.
· Some women notice a reddish coloring on the palms of their hands known as palmar erythema. This coloring is another estrogen effect, and it, too, will go away.
· Skin tags (small, benign skin growths) are a common occurrence, although it isn’t totally clear why they develop. Fortunately, they, too, fade away or disappear after pregnancy. Because they’re likely to resolve in time, you don’t need to rush to the dermatologist to have them removed, unless they’re really bothersome.
Illustration by Kathryn Born, MA
FIGURE 2-2: Some common skin changes associated with pregnancy.
Checking In: Prenatal Visits
In the second trimester, you’re likely to see your practitioner about once every four weeks. At each visit, he checks your weight, your blood pressure, your urine, and the fetal heart rate. You may want to bring up any questions you have about fetal movement, childbirth classes, your weight gain, and any unusual symptoms or discomfort you have.
As your baby grows and changes, so does the range and scope of possible prenatal tests. In the second trimester, you’ll likely undergo a blood test or two and an ultrasound for a general scan of your baby’s anatomy, growth, and well-being. At this point, you can find out the sex of your baby. Amniocentesis may also be performed in the second trimester. This section outlines the tests you may undergo.
Second-trimester blood tests
The blood tests covered in this section usually yield normal results, but if yours are at all unusual, you may need further testing — an ultrasound examination, perhaps. But keep in mind that further testing doesn’t necessarily mean that anything is wrong — only that your practitioner is being careful to ensure that everything is okay.
Alpha-fetoprotein screen
MSAFP stands for maternal serum alpha-fetoprotein, a protein made by the fetus that also circulates in the mother’s bloodstream. Doctors use a simple blood test to check the level of MSAFP, usually sometime between 15 and 18 weeks. The test result is affected by weight, race, and preexisting diabetes, so it has to be adjusted for those factors. An elevated MSAFP is expressed as more than 2.0 or 2.5 multiples of the median, or MOMs, for women carrying only one baby and more than 4.0 or 4.5 MOMs for mothers of twins. (In triplets and quadruplets, the measurement hasn’t been well studied.)
Abnormal MSAFP can usually indicate whether a pregnancy is at risk for certain complications and may indicate
· Underestimation of the fetus’s age (how far along you are)
· The presence of twins or more
· Bleeding that may have occurred earlier in the pregnancy
· Neural tube defects (spina bifida, anencephaly, and others)
· Abdominal wall defects (protrusion of the fetus’s abdominal contents through a defect in the abdominal wall)
· Rh disease (see Book 6, Chapter 2) or other conditions associated with fetal edema (abnormal fluid collection in the fetus)
· Increased risk for low birth weight, preeclampsia, or other complications (see Book 6, Chapter 2)
· A rare fetal kidney condition known as congenital nephrosis
· Fetal death
· Other fetal abnormalities
Remember that the MSAFP test is only a screening test. Most women with an elevated MSAFP have a normal fetus and continue to have a completely normal pregnancy. Only about 5 percent of women with a positive maternal serum screen actually have a fetus with a neural tube defect. On the other hand, the test isn’t perfect, and therefore it can’t identify all abnormal fetuses. To reduce the risk of getting a false positive result (that is, an abnormal test result but a normal fetus), a positive test should be repeated (especially if it’s only mildly elevated or under 3.0 MOMs), and an ultrasound should be performed to confirm the fetus’s age. If a test comes back elevated a second time or if it’s greater than 3.0 MOMs on the first screen, a detailed ultrasound exam should be done to look for abnormalities.
If you have two elevated MSAFP tests, a very high single test, or a questionable ultrasound for spine and head defects, you may want to have an amniocentesis to check the level of AFP in the amniotic fluid (see the section “Testing with amniocentesis” later in this chapter). Your practitioner can also check the amniotic fluid for a substance called acetylcholinesterase, which is present if the fetus has an open neural tube defect (see the nearby sidebar “Understanding neural tube defects”).
In most cases, the amniotic fluid AFP is negative and the pregnancy continues normally. Some studies suggest, however, that women who have an abnormal MSAFP and then a normal amniotic fluid AFP may be at risk for preterm delivery, low birth-weight babies, or hypertension. If you fit the pattern, your doctor may suggest that you and your baby be closely observed, either with ultrasound or with other tests of fetal well-being, such as nonstress tests (see Book 2, Chapter 3). Specific protocols for fetal monitoring vary from doctor to doctor.
UNDERSTANDING NEURAL TUBE DEFECTS
The baby’s central nervous system begins as a flat sheet of cells that rolls up into a tube as it matures. The front of the tube, which closes at about day 23 of life, becomes the brain. The other end of the tube, which closes at about day 28 of life, becomes the lower end of the spinal cord. If either end fails to close for some reason (nobody knows why it sometimes doesn’t), a neural tube defect occurs. The most common neural tube defects are spina bifida (an opening in the spine), anencephaly (absence of the skull), and encephalocele (an opening in the skull). These defects cause abnormalities in the nervous system such as paralysis, extra fluid in the brain, or mental retardation. Fetuses with anencephaly usually don’t survive more than a few days after birth.
This all sounds pretty scary, but fortunately, these defects are rare. In the United States, a neural tube defect occurs about once in every 1,000 babies born. The incidence in the United Kingdom is higher: 4 to 8 cases in every 1,000 babies. In Japan, the incidence is quite low, at about 1 case per 2,000 babies. No one knows exactly why the incidence varies among countries, but it has something to do with the interaction between the environment and one’s genetic makeup. If you or your baby’s father has a family history of neural tube defects, let your practitioner know at your first visit, because that slightly raises your risk of having a baby with a neural tube defect, and you can discuss your options for prenatal diagnosis (ultrasound or amniocentesis).
You can reduce the likelihood of having a baby with a neural tube defect by taking folic acid before you conceive and by getting your blood sugar under control if you have diabetes. If you had a previous pregnancy in which a neural tube defect was diagnosed or if you have a family history of this condition, increase the amount of folic acid you take at the beginning of pregnancy to 4 mg per day. The earlier in pregnancy you start taking it, the better it is at preventing neural tube defects.
The quadruple test for Down syndrome
Another test that can be performed with the same sample of blood that’s used for the MSAFP during the second trimester is a screening test for Down syndrome — the most common chromosomal abnormality in babies. This test can also help identify women at risk of having babies with other chromosomal abnormalities, like trisomy 18 or trisomy 13 (an extra copy of the number 18 or 13 chromosome). These particular chromosomal abnormalities are associated with severe birth defects and are often incompatible with life.
Your practitioner performs this test by measuring four substances in the blood: MSAFP, hCG (human chorionic gonadotropin), estriol (a form of estrogen), and inhibin A (a substance secreted by the placenta).
Your practitioner uses the results of these tests to calculate risk for Down syndrome. In women under the age of 35, the test detects Down syndrome in about 80 percent of the cases where it’s present. (In other words, if 100 women carrying fetuses with Down syndrome had the test, the condition would be diagnosed in about 80 of them.) This test is only a screening, so even if the result is abnormal, the fetus is normal in the majority of cases. If your test is abnormal, your practitioner will discuss with you the possibility of having an amniocentesis to check the baby’s chromosomes. The quad test is often combined with the first-trimester tests described in Book 2, Chapter 1 to improve the detection of Down syndrome.
Unlike the screen for neural tube defects, which yields a high MSAFP and is often repeated when abnormal, the screens for Down syndrome should not be repeated, because doing so will only provide a less accurate result.
Cell-free fetal DNA
If abnormalities are suspected on your baby’s ultrasound, your doctor may recommend sending off a sample of your blood to check the baby’s chromosomes. This test examines the cell-free fetal DNA that circulates in your blood and is the same test that is discussed in Book 2, Chapter 1.
Glucose screen
The glucose screen is a test to identify women who may have gestational diabetes. Your practitioner conducts the test by first having you drink a super-sweet glucose mixture (it tastes like flat soda) and then, exactly one hour later, drawing a sample of blood. He checks this sample for the level of glucose (sugar). High levels indicate that you’re at risk for gestational diabetes. To understand why treating gestational diabetes is important, go to Book 6, Chapter 3.
The one-hour screening test is usually performed between 24 and 28 weeks, though some doctors do it twice — once early in the pregnancy and again at 24 to 28 weeks. About 25 percent of obstetricians test only those women who are at risk for gestational diabetes. The risk factors, which follow, are broad, and about 50 percent of all pregnant women have one of them:
· Maternal age greater than 25 years
· Previous birth of a large infant
· Previous unexplained fetal death
· Previous pregnancy with gestational diabetes
· Strong family history of diabetes
· Obesity
If your initial glucose screening test is abnormal, you don’t necessarily have gestational diabetes. (Remember, it’s only a screening test.) Only about 5 percent of pregnant women actually develop gestational diabetes (although 15 percent may screen positive). Your practitioner will recommend another test that tells whether gestational diabetes is really present. This three-hour test involves drawing blood after you fast overnight, having you drink a different glucose mixture, and then drawing blood three more times, at one, two, and three hours later. Some practitioners recommend eating an extra helping of pasta or rice for the three days before the test (called carbohydrate loading) in order to get your body ready for the test.
A test is considered positive — or abnormal — if two (or more) of the four blood levels are in the abnormal range. If you test positive for gestational diabetes, your doctor will put you on a special diet and check your glucose levels throughout the remainder of your pregnancy. If you have elevated glucose levels despite adhering to this special diet, you may need to be on insulin or an oral medication to keep your sugars well controlled. (See Book 6, Chapter 3 for more on this topic.)
Complete blood count (CBC)
Many obstetricians check a complete blood count at the same time that they do your glucose test in order to see whether you’ve developed significant anemia (iron deficiency) or a variety of other (less-common) problems. Anemia is common during pregnancy, and some women need to take extra iron. A CBC also gives your physician a platelet count (platelets help with clotting).
Looking at sound waves: Ultrasound
An ultrasound (also referred to as a sonogram) exam is an incredibly useful tool that allows you and your doctor to see the baby inside your uterus. A device called a transducer emits sound waves. The sound waves are reflected off the fetus and converted into an image that appears on a monitor. You can see almost all the structures in the fetus’s body, and you can see the fetus moving around and performing all her normal activities — kicking, waving, and so on. The best time to view the baby’s anatomy is around 18 to 22 weeks.
An ultrasound exam doesn’t hurt. Your practitioner spreads gel or lotion over your abdomen and then moves the transducer around through the gel (see Figure 2-3). A full bladder isn’t necessary, because the amniotic fluid surrounding the fetus provides the liquid needed to transmit the sound waves to create a clear or detailed picture. Picture quality varies, depending on maternal fat, scar tissue, and the fetus’s position.
Illustration by Kathryn Born, MA
FIGURE 2-3: An ultrasound test performed during the second trimester.
A doctor (an obstetrician, a perinatologist, or a radiologist) or an ultrasound technologist may perform the ultrasound. Sometimes a technologist does a preliminary exam, and the doctor comes in later to check on images or review the printed pictures.
What an ultrasound can reveal
Ultrasound is like a checkup for the fetus. It can provide information about the following:
· Number of babies
· Gestational age
· Rate of fetal growth
· Fetal position, movement, and breathing exercises (the fetus moves her chest and abdomen as if she were breathing air)
· Fetal heart rate
· Amount of amniotic fluid
· Location of placenta
· General fetal anatomy, including the identification of some birth defects
· The baby’s sex (after 15 to 16 weeks), although depending on the position of the fetus, the sex may be difficult to discern
Typically, the examiner measures the fetus first and then studies her anatomy. The extent and degree of detail of the exam varies from woman to woman and doctor to doctor. A detailed ultrasound can examine these structures:
· Arms and legs
· Bladder
· Brain and skull
· Face
· Genitalia
· Heart, chest cavity, and diaphragm
· Kidneys
· Spine
· Stomach, abdominal cavity, and abdominal wall
The technology used in ultrasounds has been in widespread use for more than 40 years, and overwhelmingly most studies show no harmful consequences for the baby or mom. In addition, the information provided by an ultrasound examination has been shown to have many health benefits. For example, certain conditions (such as bladder outlet obstruction) may be treated during the pregnancy, and the diagnosis of others (such as a congenital heart defect) allow for careful planning for delivery. Detection of problems with fetal growth or amniotic fluid volume lets your doctor know that close surveillance of the pregnancy may be indicated.
Reasons for having an ultrasound
Whether and how often you need an ultrasound depends on your particular risk factors, your doctor’s preferences, and your insurance coverage. Some doctors recommend that all women have an ultrasound exam at about 20 weeks; others feel that it’s unnecessary if your risks are low. Multiple ultrasound examinations may be needed if any of the following conditions arise:
· You’re carrying twins or more.
· Your doctor suspects that the baby is too small or too large for her age.
· Your doctor suspects that you have too little or too much amniotic fluid.
· You’re at risk for preterm labor or incompetent cervix (find out more later in this chapter and Book 6, Chapter 2).
· You have diabetes, hypertension, or other underlying medical conditions (see Book 6, Chapter 2).
· You’re bleeding.
· Your doctor wants to do a biophysical profile, which is an assessment of fetal well-being that looks at movement, breathing exercises, amniotic fluid volume, and fetal tone (ability to flex the muscles).
Recently, doctors have also used ultrasound to get an accurate measurement of the cervix (the uterus’s opening) in women at risk for preterm delivery or incompetent cervix. Your practitioner places a transducer in the vagina to measure the cervix’s length and check the appearance of the lower part of the uterus.
3-D AND 4-D ULTRASOUND
Most perinatal ultrasound centers now have special machines with the capability of showing three-dimensional images of the fetus, known as 3-D ultrasound. 4-D ultrasound is similar, but instead of seeing a still (static) 3-D picture, you can see the fetus move. These high-tech ultrasound machines aren’t available everywhere, and no medical data has shown that a 3-D or 4-D ultrasound is better at detecting problems than the usual 2-D image. However, you may see certain features in the fetus better, such as the face, hands, and feet. Also, many women experience a real bonding with the fetus, seeing it three-dimensionally. If a 3-D or 4-D ultrasound is available, you may enjoy and benefit from the experience. If not, don’t feel bad; you’ll have the baby — all four dimensions of it — in real life soon enough.
Testing with amniocentesis
Amniocentesis is a test performed by inserting a thin, hollow needle into the amniotic fluid and then withdrawing some of the fluid through the needle into a syringe (see Figure 2-4). The amniotic fluid can then be tested in a variety of ways. If your practitioner performs a genetic amniocentesis — a check of fetal chromosomes — he usually conducts it at 15 to 20 weeks. Your practitioner may perform amniocentesis for other reasons, like checking for lung maturity in the baby, at any time later in the pregnancy.
Illustration by Kathryn Born, MA
FIGURE 2-4: An amniocentesis procedure.
During the amniocentesis procedure, you lie flat on your back on top of a table. Your doctor cleans your abdomen with an iodine solution. Using ultrasound to locate an area of amniotic fluid that is away from the baby, your doctor inserts a thin needle through your abdomen and uterus into the amniotic sac. After withdrawing enough amniotic fluid (usually about 15 to 20 cc, or 1 to 2 tablespoons), he removes the needle.
A common misconception is that the needle is inserted through the navel. The exact point of insertion depends on where the fetus, the placenta, and the amniotic sac are located within the uterus. You may have heard that the amniocentesis needle is exceptionally long, and you may be afraid of long needles. But the needle’s length, which enables it to reach the amniotic sac, doesn’t make it painful. A needle’s thickness determines how uncomfortable it is, and an amniocentesis needle is very thin.
The procedure, which typically lasts no longer than one to two minutes, is mildly uncomfortable but not terribly painful. Many women feel a slight, brief cramping sensation as the needle goes into the uterus and then a weird pulling sensation as the fluid is withdrawn through the needle. Some women worry about moving too much during an amniocentesis. This usually isn’t a problem. If you really are flinching or moving too much, your doctor will let you know. Also, it’s a common misconception that the risk of an amniocentesis is that the needle may hurt the baby. Your doctor will place the needle in a place well away from the baby. Sometimes a fetus moves toward the needle, but this doesn’t cause any harm. Your doctor will simply reposition the needle to a safe place and wait for the baby to stop moving.
Afterward, your doctor may advise you to rest and avoid strenuous activity and sex for one to two days. Most women cramp a bit the day of the procedure, which is expected and normal.
A genetic amniocentesis primarily tests to see that 23 chromosome pairs are present and that their structure is normal. It doesn’t routinely test for all possible genetic diseases or birth defects. The amniotic fluid cells must be incubated before your doctor can read the results of a genetic amniocentesis. Results are usually available in one to two weeks.
If prenatal blood studies show that you’re Rh-negative, your doctor will give you an injection of Rh-D immune globulin (such as Rhogam or Rhophylac), which helps prevent Rh sensitization.
Risks and side effects of amniocentesis
Following are some side effects that may occur, although not all patients have these symptoms or problems after an amniocentesis:
· Cramping: Some women experience cramping for several hours after the procedure. The best treatment for this cramping is rest. Some practitioners recommend a single glass of wine to help ease the discomfort.
· Spotting: This may last one to two days.
· Amniotic fluid leak: A leakage of 1 to 2 teaspoons of fluid through the vagina occurs in 1 to 2 percent of patients. In the great majority of these cases, the membrane seals over within 48 hours. Leakage stops and the pregnancy continues normally. If you experience a large amount of leakage or persistent leakage, call your doctor.
· Fetal injury: Injury to the fetus is extremely rare, given the use of ultrasound guidance.
· Miscarriage: Although amniocentesis is considered very safe, it’s still invasive and is associated with a small risk of pregnancy loss. Recent studies have shown that the risk of pregnancy loss after amniocentesis is much less than the 0.5 percent risk previously quoted and is probably closer to about 1 in 1,000.
An amniocentesis performed later in the pregnancy — later than 20 weeks — doesn’t carry the same increased risk of miscarriage. It carries only a very small risk of infection, rupture of membranes (breaking the water), or onset of labor.
Your decision to undergo the procedure must weigh both risks and benefits, which vary according to the individual. For example, a 40-year-old woman with a history of infertility may not want to undergo any test that carries an increased risk of miscarriage, even though she stands a higher risk of carrying a fetus with a chromosomal abnormality. On the other hand, a 32-year-old maternal–fetal medicine specialist who sees patients with a multitude of problems every day may opt to undergo an amniocentesis even though her risk of having a fetus with a chromosomal abnormality is relatively low — lower, in fact, than her risk of miscarriage because of the test. The peace of mind may be worth the small increased risk of miscarriage.
Reasons for having an amniocentesis
Your practitioner may recommend a genetic amniocentesis for the following conditions or situations:
· Your age is 35 or more at your due date. This age recommendation also depends on the number of babies you’re carrying. For example, if you’re carrying twins, your practitioner may offer an amniocentesis at age 33.
· You had an elevated MSAFP (see the “Alpha-fetoprotein screen” section earlier in this chapter).
· You had abnormal results from Down syndrome screening (during either your first or second trimester).
· Your ultrasound exam was abnormal, indicating, for example, poor fetal growth or suspected structural abnormalities.
· You had a previous child or previous pregnancy with a chromosomal abnormality.
· You’re at risk of having a baby with a certain genetic disease.
· You and your partner have concerns and want to confirm that the chromosomes are normal.
Your practitioner may perform amniocentesis for other reasons:
· Infections leading to preterm labor: An infection within the amniotic fluid may be a cause of preterm labor. Your practitioner can send the fluid to a lab for tests to look for any such infection. If an infection is present, your doctor may want to deliver your baby right away to minimize harm to you and the baby.
· Other infections: Some patients may find that they’re at risk of developing infections such as toxoplasmosis, CMV (cytomegalovirus), or parvovirus (see Book 6, Chapter 3). The amniotic fluid can be tested for evidence of such problems in patients at risk.
· Rh sensitization: Patients with Rh sensitization are sometimes monitored with a test known as delta OD-450, in which the amniotic fluid is examined for evidence of broken-down fetal red blood cells. However, most doctors instead perform a special type of Doppler ultrasound called an MCA (middle cerebral artery) Doppler (see the section “Doppler studies” later in this chapter). Go to Book 6, Chapter 2 for info on Rh sensitization.
· Lung maturity studies: Sometimes your doctor needs to find out whether the fetus’s lungs are mature enough for the baby to be delivered. Certain tests on the amniotic fluid can determine the maturity of the lungs.
Other prenatal tests and procedures
Not all the tests or procedures in this section are performed in all pregnancies — only when a specific problem is present. In fact, most of these tests are rarely done and are usually done in centers that specialize in fetal medicine. If needed, they’re usually performed in the second or third trimester.
Fetal blood sampling
For fetal blood sampling — also known as PUBS (percutaneous umbilical blood sampling) or cordocentesis — a doctor withdraws fetal blood from the umbilical cord. This test lets your doctor obtain blood for rapid chromosomal diagnosis when time is critical, although testing cell-free fetal DNA in the mother’s blood can also be used in this situation (see the earlier section “Cell-free fetal DNA”).
Your doctor may do fetal blood sampling in order to diagnose fetal infections, detect evidence of fetal anemia, or diagnose and treat a condition called nonimmune hydrops, in which fluid accumulates abnormally in the fetus. A maternal–fetal medicine specialist performs the procedure under ultrasound guidance. The procedure is similar to an amniocentesis, except that the doctor directs the needle into the umbilical cord rather than into the amniotic fluid. Risks are low but include infection, rupture of the membranes, or fetal loss. (The risk of fetal loss is about 1 percent.)
Some fetuses develop anemia, which can be treated in utero (within the womb) with a blood transfusion directly into the umbilical cord. Conditions that may lead to anemia include certain infections (like parvovirus), genetic diseases, or certain blood group incompatibilities (see Book 6, Chapter 2).
Fetal echocardiogram
A fetal echocardiogram is basically a sonogram focused on the fetal heart. A maternal–fetal medicine specialist, a pediatric cardiologist, or a radiologist usually performs this procedure. You may need a fetal echo if you have a history of diabetes or a family history of congenital heart disease, or if an ultrasound shows any signs of a heart abnormality. Sometimes your practitioner recommends a fetal echo if he sees any structural problem on ultrasound, because heart abnormalities are often associated with other birth defects.
Doppler studies
Ultrasound can be used to perform Doppler studies of fetal and umbilical blood flow. These studies are a way of assessing blood flow to various organ systems and also within the placenta. A Doppler study is sometimes used as a test of well-being in fetuses with IUGR (intrauterine growth restriction) — see Book 6, Chapter 2 for more on IUGR. MCA Dopplers measure the blood flow through a major blood vessel in the fetal brain and can detect fetuses who may be anemic from an infection or a blood group incompatibility.
Recognizing Causes for Concern
This section covers certain problems that can develop during the second trimester and symptoms that you should discuss with your practitioner.
The following is a list of second-trimester symptoms that require some attention. If you experience any of them, call your practitioner:
· Bleeding
· An unusual sense of pressure or heaviness
· Regular contractions or strong cramping
· A lack of normal fetal movement
· High fever
· Severe abdominal pain
Bleeding
Some women experience bleeding in the second trimester. Possible causes include a low-lying placenta (placenta previa), premature labor, cervical incompetence, or placental abruption (all covered in Book 6, Chapter 2). Sometimes the doctor can’t find a cause. If you do experience bleeding, it doesn’t necessarily mean you’ll have a miscarriage, but you should call your doctor. He’ll probably recommend you have an ultrasound exam and be monitored to make sure that you’re not contracting. Bleeding may increase the risk for premature delivery, so your doctor may recommend that your pregnancy come under extra-close surveillance.
Fetal abnormality
Although the vast majority of pregnancies proceed normally, about 2 to 3 percent of infants are born with some abnormality. Most of these abnormalities are minor, although some do lead to significant problems for the newborn. Some are due to chromosomal problems, and others stem from abnormal development of organs and structures. Many of these problems, though not all of them, can be diagnosed on a prenatal ultrasound exam (see the earlier section “Looking at sound waves: Ultrasound”). When confronted with any such problem, the most important first step is to gather all the available information about it so you know what to expect and what the treatment options are. Keep in mind that even specialists may not be able to tell you everything to expect until your baby is born and they can further evaluate the situation.
Cervical insufficiency/incompetent cervix
During the second trimester, usually between 16 and 24 weeks, some women develop a problem known as cervical insufficiency or incompetent cervix. The cervix opens up and dilates, even though the woman feels no contractions. This condition may lead to miscarriage. A woman who develops this condition ordinarily doesn’t notice any symptoms, although sometimes she may report feeling pelvic heaviness or pressure that’s out of the ordinary, or she may notice some spotting. Most women who experience cervical insufficiency do so for no identifiable reason. Others may have one of the following risk factors:
· Cervical trauma: Some evidence suggests that multiple D&Cs (dilation and curettage; see Book 2, Chapter 1) or procedures called cervical cone biopsy or LEEP (in which a cone-shaped portion of the cervix is removed in the diagnosis or treatment of cervical abnormalities) can increase the risk of cervical insufficiency. A significant tear of the cervix during a prior delivery may also increase the risk for this disorder.
· Multiple gestations: Some obstetricians believe that carrying multiple babies, especially triplets or more, may increase the risk for cervical insufficiency and advocate that all patients with triplets or more have a cerclage (a stitch in the cervix) put in. Some patients who have undergone a procedure called multi-fetal pregnancy reduction (see Book 6, Chapter 1) may also be at increased risk for incompetent cervix, although routine cerclage placement isn’t recommended for them at this time.
· Prior history of cervical insufficiency: After you’ve had a cervical insufficiency, your risk of having it again in a subsequent pregnancy is increased.
In cases in which a cervical insufficiency is diagnosed before the pregnancy is lost, attempts can be made to hold the cervix shut with a stitch, called a cerclage, around the cervix. The cerclage is usually placed at 12 to 14 weeks, although it’s occasionally performed as an emergency procedure later in the pregnancy. Doctors most commonly perform the procedure in the hospital under spinal or epidural anesthesia, but the woman is usually discharged later the same day.
Some women with a cerclage notice they have a heavy discharge throughout pregnancy. If you need to have a cerclage, talk to your doctor about how active you can be — whether you can have sex and how much exercise is advisable. Complications associated with emergency cerclage include infection, contractions, rupture of membranes, bleeding, and miscarriage. The same complications can occur with elective cerclage, but they’re unusual.
Many doctors are now using a pessary, a plastic/rubber device that is inserted into the vagina to take some of the pressure off of the cervix. The device is easily inserted and removable, so it doesn’t carry the same risks as a cerclage because no needles are involved.
FOR PARTNERS: HAVING SEX IN THE SECOND TRIMESTER
For many women, the libido is back on the ascent during the second trimester, which is a big sigh of relief for any guy who has patiently waited through her nausea, exhaustion, discomfort, and lack of sexual energy for some long-awaited sex. In fact, some women become very sexual during this time because they’re flush with hormones and feeling in touch with their bodies. So forget what you may have heard — sex during pregnancy is safe as long as your partner is having a normal pregnancy. Your baby is protected by an amniotic sac and the cervix, which is sealed tightly by a thick mucus plug, which keeps out foreign and unwanted intruders. (So, no, your penis isn’t long enough to hit or poke the baby during sex. The baby can’t see your penis when you’re having sex and isn’t afraid of your penis during sex. Your semen won’t get all over the baby upon completion of sex.)
Don’t be surprised if your partner needs to take it slowly in the beginning. Stop at any signs of discomfort. As the baby bump continues to expand, you’ll likely find yourselves exploring new positions that offer support for your partner’s stomach. Many women are most comfortable on their sides or even up on their knees and can use pillows for stomach support. Spotting and cramping that can last up to 24 hours can occur after sex. If you or your partner has any questions or concerns about either, call her medical practitioner.
One warning: If your partner desires oral sex, it’s absolutely safe. Just make sure not to blow air into the vagina because this can cause an embolism, which can be fatal for the baby and the mother-to-be.
In a few instances, sex during pregnancy isn’t recommended. Talk with your partner’s doctor or midwife prior to having sex if your partner has dealt with any of the following issues:
· Bleeding: Sometimes vaginal bleeding ranging from normal to potentially life-threatening can occur during the early months of pregnancy, and sex can cause the cervix to bleed.
· Leaking amniotic fluid: Any time amniotic fluid is leaking, the sterile barrier between the baby and the outside world is broken, and infection can enter into the uterus and infect the baby. No sex after her water breaks!
· Miscarriage: If your partner has ever had a miscarriage, or if a medical professional has said that she’s at risk for having one, check before having sex.
· Multiple pregnancy: Because multiples often deliver early, you need to avoid anything that can upset the delicate balance between no children and two (or more) children — sex included. Semen contains substances that may bring on labor if the tendency for preterm delivery exists. Besides, your partner probably has enough going on in there already.
· Placenta previa: With the placenta close to or overlying the cervix in placenta previa, having sex can cause life-threatening bleeding.
· Preterm labor: If your partner gave birth to a previous child prematurely, get clearance to make sure having sex is safe.
· Weakened cervix: Sometimes called an incompetent cervix, this condition can lead to the cervix dilating before the baby is full term, which can lead to miscarriage. A stitch is often placed into the cervix to keep it closed. Sex can cause uterine contractions that disrupt the stitch.
A female orgasm during low-risk pregnancy won’t cause your partner to go into labor prematurely. Contractions of the uterus associated with sex aren’t the same as those experienced during labor (and your partner is very thankful for this!). However, orgasm achieved by any method can start contractions that can lead to preterm labor in high-risk pregnancy, so put the vibrator away for the duration as well.
Some medical practitioners recommend avoiding sex during the final weeks of pregnancy because of the prostaglandins in semen, which are hormones that can stimulate contractions. On the flip side, if your partner is overdue, you may get a “prescription” for sex to jump-start the contractions.