IN THIS CHAPTER
Getting a glimpse of your baby’s development in the first trimester
Coping with the physical symptoms of early pregnancy
Understanding what happens at your first prenatal appointment
Addressing genetic concerns that may affect your baby
Knowing what constitutes cause for concern
The first trimester of your pregnancy is an exciting time, full of many changes for you and especially for your baby, which — in just 12 short weeks — grows from a single cell to a tiny being with a beating heart and functioning kidneys. With all that change going on in your baby, you can certainly expect many changes in your own body — from fatigue and nausea to newly voluptuous (va-va-voom!) but tender breasts. Through it all, you need to know what’s normal and what’s worth a call to your practitioner, whom you begin visiting regularly at this point. This chapter gives you a snapshot of what to expect.
Weeks in this chapter refers to menstrual weeks, which means weeks from the last menstrual period, not weeks from conception. So at eight weeks, the baby is really six weeks from conception. We describe how doctors calculate the timing of pregnancy in Book 1, Chapter 1.
Following the Numbers: How the Embryo Grows
Pregnancy begins when the egg (or oocyte) and sperm meet, which happens in the fallopian tube. At this stage, the egg and sperm together form the zygote — a single cell. The zygote divides many times into a cluster of multiple cells called a blastocyst, which travels down the fallopian tube and into the uterus (also called the womb). When it reaches the uterus, both you and your baby begin to experience major changes.
On or about the fifth day of development, the blastocyst attaches to the blood-rich lining of the uterus during a process called implantation. Part of the blastocyst grows to become the embryo (the baby in the first eight weeks of development), and the other part becomes the placenta (the organ that implants into the uterus to provide oxygen and nourishment to the fetus and eliminate its waste products).
From the blastocyst, the embryo develops into three tissue layers: the endoderm, mesoderm, and ectoderm. These three layers, which ultimately give rise to all the structures of the body, are initially organized into a flat disk. Around the beginning of the fourth week of embryonic development, the flat disk begins to fold and form a cylinder. At this point, the embryo begins to take on the form of the general body plan, with a mouth region and an anal region. Between weeks four and eight, all the organ systems that you find in an adult will be forming.
After the eighth week of your pregnancy, the developing embryo is referred to as a fetus. Amazingly, by this time, almost all the baby’s major organs and structures are already formed. The remaining 32 weeks allow the fetus’s structures to grow and mature. The brain, although also formed very early, isn’t mature at birth; rather, it continues to develop into adulthood.
Your baby grows within the amniotic sac in the uterus. The amniotic sac is full of clear fluid, known as amniotic fluid. This water balloon–like structure actually comprises two thin layers of membrane called the chorion and amnion (which together are known as the membranes). When people talk about water breaking, they’re referring to the rupturing of those membranes that line the uterus’s inner walls. The baby “swims” in this fluid and is attached to the placenta by the umbilical cord. Figure 1-1 shows a diagram of an early pregnancy, including a developing fetus and the cervix, which is the uterus’s opening. The cervix opens up, or dilates, when you’re in labor.
Illustration by Kathryn Born, MA
FIGURE 1-1: An early pregnancy.
The placenta begins to form soon after the embryo implants in the uterus. Maternal and fetal blood vessels lie very close to one another inside the placenta, which allows various substances (such as nutrients, oxygen, and waste) to transfer back and forth. The mother’s blood and the baby’s blood are in close contact, but they don’t actually mix.
The placenta grows like a tree, forming branches that in turn divide into smaller and smaller ones. The tiniest buds of the placenta are called the chorionic villi, and it’s within these villi that small fetal blood vessels form. About three weeks after fertilization, these blood vessels join to form the baby’s circulatory system, and the heart begins to beat.
By the end of the eighth week, arms, legs, fingers, and toes begin to form, and the embryo begins to perform small, spontaneous movements. If you have an ultrasound examination performed in the first trimester, you can see these spontaneous movements on the screen. The brain enlarges rapidly, and ears and eyes appear. The external genitalia also emerge and can be differentiated as male or female by the end of the 12th week, although sex differences are not yet detectable by ultrasound.
By the end of the 12th week, the fetus is about 4 inches long and weighs about 1 ounce. The head looks large and round, and the eyelids are fused shut. The intestines, which protruded slightly into the umbilical cord at about week 10, are by this time well inside the abdomen. Fingernails appear, and hair begins to grow on the baby’s head. The kidneys start working during the third month. Between 9 and 12 weeks, the fetus begins to produce urine, which you can see within the small fetal bladder on ultrasound.
TAKE TWO: HOW TWINS FORM
Twins can form in two ways: Either two eggs are produced (ovulated) and two sperm fertilize the eggs, or one egg is fertilized by one sperm and the embryo splits into two very early in development (early in the blastocyst stage). If two eggs are fertilized, the genetic information contained in each embryo is different from the other, just like any other siblings. These twins are called fraternal twins. If one egg is fertilized and splits, the resulting two embryos are genetically identical, and you have identical twins.
Twins (or higher-order multiples) are more common in women who undergo in vitro fertilization (IVF), most often because two (or more) embryos fertilized in a petri dish are placed in the uterus and implanted. It’s still possible, however, to have identical twins when a single blastocyst is transferred to the uterus and it splits into two embryos later.
Adapting to Your Body’s Changes
Your baby isn’t the only one growing and changing during your pregnancy. Your body also has to adjust, and the adjustments it makes aren’t always the most pleasant and comfortable for you. Being prepared for what lies ahead can help ease your mind. The following sections let you know what’s in store for you during the first trimester.
Breast changes
One of the earliest and most amazing changes in your body happens to your breasts. Even during the first month of pregnancy, most women notice that their breasts grow considerably larger and feel very tender. The nipples and areolae (the circular areas around the nipples) also grow bigger and may begin to darken.
Breast changes are caused by the large amounts of estrogen and progesterone your body produces during pregnancy. These hormones cause the glands in your breasts to grow and branch out in preparation for milk production and breastfeeding after the baby is born. Blood supply to the breasts also increases markedly. You may notice large, bluish blood vessels coursing along your breasts.
Plan to go through several bra sizes while you’re pregnant — and don’t skimp on buying new bras. Good support helps reduce stretching and sagging later on. Although some women like the way they look with larger breasts, others feel self-conscious. Whichever way you feel, we guarantee other pregnant women feel the same way, so don’t be embarrassed about it.
Fatigue
During the first trimester, you’re likely to feel overwhelming fatigue. This fatigue may be a side effect of all the physical changes your body is experiencing, including the dramatic rise in hormone levels. Rest assured your exhaustion will probably go away somewhere around the 12th to 14th week of your pregnancy. As your fatigue lessens, you’ll probably feel more energetic and almost normal, until about 30 to 34 weeks into your pregnancy, when you may tire out again. In the meantime, remember that fatigue is nature’s way of telling you to get more rest. If you can, try to catch a short nap during the day and go to bed earlier than usual at night.
Any-time-of-day sickness
For some women, the nausea that can strike during the first trimester is worse in the mornings, maybe because the stomach is empty at that time of day. But ask anyone who’s had morning sickness, also known as nausea and vomiting of pregnancy (NVP), and she’ll tell you it can hit at any time. It often starts during the fifth or sixth week of pregnancy and goes away, or at least becomes much less severe, by the end of the eleventh or twelfth week. It can last longer, and in fact about 10 percent of women have symptoms up to 16 weeks! If you’re carrying twins or more, don’t be surprised if the NVP is worse than expected, because the higher hormone levels make the nausea even more extreme.
Fortunately, there are things you can do to ameliorate your symptoms. If you’re less than six weeks pregnant and experiencing NVP, you can take folic acid alone instead of your prenatal vitamin. Folic acid is the main supplement that you need early in your pregnancy, and it’s much less likely to upset your stomach than the multivitamin is. Check with your doctor for the correct dose for you, and head to Book 1, Chapter 4, which has other suggestions on ways to keep nausea at bay. Above all, don’t compound the problem by worrying about it. The nausea is harmless — to you and the baby. Your optimal weight gain for the first three months is only 2 pounds. Even losing weight probably isn’t a big problem.
If you’re really bothered by the nausea, talk to your doctor about over-the-counter or prescription medications. Occasionally, the nausea and vomiting are so severe that you develop a condition called hyperemesis gravidarum. The symptoms include dehydration and weight loss. If you develop hyperemesis gravidarum, you may need to be given fluids and medications intravenously. Again, talk to your doctor.
You may hear some women say that morning sickness is a sign that you’re experiencing a “normal” pregnancy, but that claim is a myth — and so is the reverse. If you’re not having morning sickness, or if it suddenly disappears, don’t worry that your pregnancy isn’t normal; just enjoy your good fortune. Similarly, you may hear that the severity of your queasiness indicates whether you’re having a girl or a boy. But that’s also a myth, so don’t buy those pink or blue outfits just yet.
Bloating
Well before the baby is big enough to stretch out your stomach, your belt may begin to feel uncomfortable, and your belly may look bloated and distended. This side effect of the hormone shift starts happening as soon as you conceive. Progesterone, one of the two key pregnancy hormones, causes you to retain water. Plus it slows down the bowels, causing them to enlarge and thus increase the size of the abdomen. Estrogen, the other key pregnancy hormone, causes your uterus to enlarge, which also makes your abdomen feel bigger. This effect is often more pronounced in second or third pregnancies because the first pregnancy causes your abdominal muscles to relax to a greater degree.
Frequent urination
From early on in your pregnancy, you may feel as if you’re spending your whole life in the restroom. During pregnancy, you need to urinate more frequently for a variety of reasons. At the beginning of your pregnancy, your uterus is inside your pelvis. But toward the end of your first trimester (at around 12 weeks), your uterus expands enough to rise up into your abdominal cavity. Your enlarging uterus may compress your bladder, which both decreases its capacity and increases the feeling that you need to urinate. Also, your blood volume rises markedly during pregnancy, and that means the rate at which your kidneys produce urine also increases.
Drink plenty of fluids during pregnancy to avoid dehydration, but try to drink more during the day and less in the evening so you aren’t up all night going to the bathroom. Caffeine is a diuretic, which increases the flow of urine, so also try decreasing the amount of caffeine you consume.
If you find yourself urinating even more than your pregnancy norm or if you feel any discomfort or burning or notice blood during urination, talk to your practitioner. When you’re pregnant, bacteria are more likely than usual to cause a urinary tract infection (UTI; see Book 6, Chapter 3).
Headaches
Many pregnant women notice that they get headaches more often than they used to. These headaches may be the result of nausea, fatigue, hunger, the normal physiologic decrease in blood pressure that starts to occur at this time, tension, or even depression. Simple pain relievers like acetaminophen (for example, Tylenol) or ibuprofen (such as Motrin or Advil) in recommended doses are often the best treatment for headaches, including migraines. Some women find that a little caffeine can also alleviate symptoms of a headache. Food and rest can usually cure headaches that are caused by nausea, fatigue, or hunger, so try eating and getting some extra sleep. If neither of those tactics works, something else is probably causing your headaches.
Some women find relief from occasional headaches by taking a combination of acetaminophen and caffeine (such as Excedrin Tension Headache). Although this combination is fine to take once in a while, don’t use it on a regular basis. Each tablet contains 65 mg of caffeine, and the package recommends two tablets every six hours — that’s a whopping 520 mg of caffeine per day and way beyond the maximum 200 mg recommended for pregnant women. This much caffeine taken on a regular basis could cause problems with your baby’s growth or, if consumed early in pregnancy, may increase your risk for miscarriage.
Avoid taking regular doses of aspirin unless recommended by your practitioner. Adult doses of aspirin can affect platelet function (important in blood clotting).
If over-the-counter medications don’t relieve your headaches, talk with your practitioner about taking a mild tranquilizer or antimigraine medication. Base your decision on whether to use migraine medications on the severity of your problem. If your headaches are chronic or recurrent, you may be better off taking medications, despite their potential effects on your fetus, because feeling bad all the time is likely more harmful to your baby’s development than any potential risks from the various medications available. As always, consult with your practitioner before taking these medications.
If your headaches are severe and unremitting, you may need a thorough medical evaluation or a referral to a neurologist. Later on in pregnancy, a headache may signal the onset of preeclampsia (covered in Book 6, Chapter 2). In that case, your headache may be accompanied by swelling of your hands and feet and by high blood pressure. If you suffer a severe headache in the late second or third trimester, call your practitioner.
Constipation
About half of all pregnant women complain of constipation. When you’re pregnant, you may become constipated because the large amount of progesterone circulating in your bloodstream slows the activity of your digestive tract. The iron in prenatal vitamins may make matters worse.
Eating plenty of high-fiber foods, drinking plenty of water, and exercising regularly can provide relief. Taking stool softeners is another option. A stool softener isn’t a laxative; it just keeps the stool soft. Stool softeners are safe during pregnancy, and you may take them two to three times a day. Head to Book 1, Chapter 4 for details on these remedies and to Book 4 for safe exercise options.
Avoid laxatives, because they can cause abdominal cramping and, occasionally, uterine contractions. For any person, pregnant or not, chronic laxative use should be avoided. If you’re extremely constipated, though, and aren’t at risk for preterm labor, you may want to talk to your practitioner about the short-term use of a very mild laxative, like a glycerin suppository or milk of magnesia.
Cramps
You may feel a vague, menstrual-like cramping sensation during the first trimester. This symptom is very common, so don’t worry. The cramping is probably related to the uterus growing and enlarging.
If you experience cramping along with vaginal bleeding, give your practitioner a call. Although the majority of women who experience bleeding and cramping go on to have perfectly normal pregnancies, sometimes these two symptoms together are associated with miscarriage. Cramping alone, without bleeding, is unlikely to be a problem.
GETTING USED TO STRANGE NEW MATERNAL HABITS
At times, you may look at your partner and wonder who this woman actually is. The sweet-tempered woman you once knew may have been replaced by someone whose head appears to be rotating at times, and the woman who used to party all night long barely makes it into the living room to collapse on the couch after work. You knew having a baby was going to change your life, but you probably didn’t expect things to change this much so early in the game.
Take heart: These are temporary changes. After her body adjusts to the new hormone levels, many of the symptoms will decrease, and your original partner will start to emerge again.
In the meantime, some of her new habits may be affecting you in a big way, and you may need to find ways to cope with them. Here are some suggestions to help you deal with a few of your least favorite early pregnancy things.
· Vomiting: Although she’s the one vomiting, sometimes you may not be far behind, and staying supportive while holding onto your own cookies can be difficult. If the sight, sounds, and smell of vomiting are getting to you, try dabbing something under your nose that smells good to you, like peppermint oil, and stay cool. People are less likely to vomit when cool air is blowing on them.
· Gaining weight: When the nausea ends, your partner may start eating like food is going to be taken off the market next week. This can be bad for her waistline, sure, but it can also be not-so-good for yours, because you may find yourself overeating just to keep up with her and matching her weight gain pound for pound. For both of your sakes, try to put a stop to the madness.
You don’t have to remind her how hard this weight is going to be to lose later. Just talk about your own weight gain and how you’re afraid you’re not going to be able to play Frisbee on the beach with the kid if you keep eating like this. Don’t turn into the food police; no one responds well to being told what they should and shouldn’t eat.
· Coping with your cravings: Sex may be the last thing on your partner’s mind in the first trimester. And some types of sex may trigger her gag reflex, which is the last thing you want to associate with a previously enjoyable activity! Although turning into a monk may not be on your list of fun things, you can cope with the words “Not tonight, honey” by being flexible. Be ready to perform when your partner is ready, because the window of opportunity can be slammed shut before you’ve had a chance to look outside.
Also experiment with touching: Depending on how open your partner is to experimentation, you can do a lot to pleasure each other that doesn’t involve intercourse. You can also practice self-release: Masturbation isn’t something most adults like to talk about, but if you have a voracious sexual appetite, and both you and your partner are okay with the idea, there’s no shame in taking the matter into your own hands, so to speak.
Going to Your First Prenatal Appointment
After the at-home pregnancy test reveals the news, set up an appointment with a practitioner. Make visits to your practitioner a regular part of your pregnancy, not only to ensure your health but also to ensure your baby’s health. Your first prenatal visit may be your first meeting with the practitioner who will guide you through your pregnancy. (If you don’t already have a practitioner selected, see Book 1, Chapter 2 for information on the kinds of care available and tips for choosing a healthcare provider.) Or you may have a long-standing relationship with an OB/GYN or family-practice doctor with whom you’ve already discussed many of the topics that are typically covered at an initial prenatal visit.
If possible, bring the father-to-be for this initial visit. His family medical history and ethnic roots are important, too. If the father isn’t part of the picture, bring your life partner or anyone else who may be helping you through the pregnancy process to the appointment. That person should have a chance to ask questions, address concerns, and find out what to expect in the coming months.
Your first prenatal visit usually lasts 30 to 40 minutes or more because your doctor has so much information to provide and so many topics to discuss. Subsequent visits are usually much shorter, sometimes only 5 to 10 minutes long. The frequency of your visits depends on your particular needs and any special risk factors you may have, but in general they’re about every four weeks during the first trimester. At these visits, the nurse or practitioner checks your urine, blood pressure, and weight and the baby’s heartbeat.
TAKING ON YOUR EMERGING SUPPORT ROLE
Don’t think of yourself as your partner’s personal assistant or as the pregnancy police. She may become a diva in her pregnancy, but it’s not your responsibility to do it all. And try to avoid becoming overprotective of your partner’s physical capabilities, especially early in the pregnancy. If everything goes well with the pregnancy, she won’t have many restrictions on her activities. But that doesn’t mean she’s going to be up for taking care of everything she’s always managed.
For the first several months — and for the last few — your partner may be too tired/nauseated/hot and so on to make dinner, walk the dog, or perform many of the household chores you used to split. Pick up the slack until she feels good enough to contribute again. When she’s back in the swing of things, she can move around and help again. After all, physical activity is beneficial for both mom and baby.
One of your main roles is ensuring that she eats healthfully and exercises if and when possible, but the way to do this is by example, not with a whip and chain in hand and bathroom scales placed in front of the refrigerator. Ask her to take walks with you, and help by preparing meals that settle her stomach and feed baby’s growing systems.
Pregnancy doesn’t turn your partner into a child, even though she’s carrying one around with her. She still gets to make her own choices about what she eats and when (or if) she exercises, and you may have to bite your tongue if she starts exceeding the weight limit for your delicate Queen Anne chairs.
In addition to supporting your partner physically, you need to support her emotionally. She’ll likely be weepier and more sensitive than normal. If you’re not the kind of guy who likes to talk about feelings, try to become that guy for a month or so.
As hormones surge and wane, roll with the punches. Let the little things go without a struggle, because your partner won’t always be able to control her reactions the way she used to. Let her dictate what’s for dinner, and if her stomach turns when you plate the exact dinner she asked for, don’t take it personally.
Understanding the consultation
During your first visit, your practitioner discusses your medical and obstetrical history with you. She asks about various aspects of your physical health as well as elements of your lifestyle that may affect your pregnancy.
Lifestyle
Your practitioner asks about your occupation to find out whether your job is sedentary or active, whether you spend your days standing or lifting heavy objects, and whether you work nights or long shifts. She also asks you about your general lifestyle — for example, smoking, heavy alcohol use, dietary restrictions, and exercise patterns.
Date of your last menstrual period
Your practitioner questions you about the start date of your last menstrual period to determine your due date. (For information on calculating your due date, see Book 1, Chapter 1.) If you don’t know exactly when your last period began, try to remember the exact date of conception. If you’re unsure about either of these dates, your practitioner may want to check on how far along you are by scheduling an ultrasound exam.
Obstetrical and gynecological history
Your provider will ask you about your obstetrical and gynecological history, including any prior pregnancies and any experiences with fibroid tumors, vaginal infections, and other gynecological problems. Your history can help determine how best to manage this pregnancy.
If you conceived with infertility treatments, inform your practitioner of this during your first prenatal visit because it brings up several points that need to be addressed. Most of the impact of infertility treatment on pregnancy outcomes is related to the higher incidence of multifetal pregnancies — twins and more. In general, children born to couples who have gone through in vitro fertilization (IVF) are as healthy as those who were conceived spontaneously. Recently, some controversy has cropped up in medical literature about an increase in certain birth defects in children born after IVF, as well as an increase in certain chromosomal abnormalities after intracytoplasmic sperm injection (ICSI). Although some studies suggest the incidence may be slightly higher, other studies document no increase at all.
Medical problems
Your practitioner asks you about any medical problems you’ve had and any surgeries you’ve undergone, including problems that aren’t gynecological in nature. Certain medical conditions may affect pregnancy, and others don’t. She also asks you about any allergies to medications you may have. Tell your practitioner so she can know everything about you and your health.
Family medical histories
The family medical histories of both you and the baby’s father are important for two reasons. First, your practitioner can identify pregnancy-related conditions that can recur from generation to generation, like having twins or exceptionally large babies. The other reason is to identify serious problems within your family that your baby can inherit. Blood tests can screen for some of these problems, such as cystic fibrosis.
Other available genetic screening tests include the following:
· Fragile X: Fragile X syndrome is the most common inherited form of mental retardation (which can vary from mild to severe disabilities) and is also the most common known cause of autism or autistic-like tendencies. Although many practitioners recommend screening all women for fragile X, the American Congress of Obstetricians and Gynecologists guidelines suggest screening only those women with a family history of fragile X syndrome or undiagnosed mental retardation, developmental delay, autism, or ovarian insufficiency. Certainly, talk with your doctor or healthcare provider if you’re interested in fragile X screening.
· Spinal Muscular Atrophy (SMA): Spinal Muscular Atrophy (SMA) is an autosomal recessive neurodegenerative disorder that occurs due to degeneration of nerve cells in the spinal cord. The disease is caused by mutations in a gene known as SMN1 (survival motor neuron gene 1). SMA is not very common (1 in 10,000 live births), although it is thought to be the most common genetic cause of infant death. Currently, couples with a family history of SMA are being offered carrier screening, although many obstetricians offer routine screening. In fact, the American College of Medical Genetics has recently recommended offering carrier testing to all couples, regardless of race or ethnicity.
· Expanded Carrier Screening for other genetic diseases: Several companies have come out with tests to screen for over 100 different genetic disorders (including the ones that are mentioned in the following section for certain ethnic groups). Almost all are autosomal recessive, meaning that you and your partner would have to be carriers for there to be a 1 in 4 chance of the fetus inheriting the disease. You may want to discuss the option of screening with your healthcare provider, as the test has to be ordered by a healthcare professional.
· Cystic fibrosis (CF): Cystic fibrosis is one of the most common genetic diseases in the United States, with an incidence of about 1 in 3,500. CF is also a recessive condition, and it’s more common among the non-Hispanic white population compared with other racial and ethnic groups. Obstetricians and geneticists recommend that CF screening, through a blood test, be offered to all pregnant couples. Speak to your doctor about CF screening during your first prenatal visit.
Ethnic roots
Even if you and your partner have family histories that are free of any known genetic disorders, your ethnic backgrounds are important because some genetic disorders occur more frequently in one ethnic group than others:
· Tay-Sachs: Jewish people of Eastern European descent are ten times more likely than others to carry the rare gene for Tay-Sachs, a disease of the nervous system that is usually fatal in early childhood. French Canadians and Cajuns (from Louisiana) also have a higher-than-normal risk of carrying this gene. Most of the time, a simple blood test can determine whether you’re a carrier of this disease.
Although Tay-Sachs and some other conditions are found more frequently among the Jewish population, individuals from other ethnic groups can still be carriers (but that’s much less common). For this reason, even if only one member of a couple is Jewish, both should still be tested, if possible.
· Sickle-cell anemia: This blood disorder is especially prevalent among people with African or Hispanic ancestors. This condition, too, is recessive, so both members of a couple must be carriers for the baby to be at risk of inheriting the disease.
· Beta-thalassemia (also known as Mediterranean anemia or Cooley’s anemia) and alpha-thalassemia: People whose ancestors come from Italy, Greece, and other Mediterranean countries are at an elevated risk of having — and passing to their children — genes for beta-thalassemia, a blood disorder. Among Asians, the analogous blood problem is alpha-thalassemia. Both of these disorders produce abnormalities in hemoglobin (the protein in red blood cells that holds onto oxygen) and therefore result in varying degrees of anemia. Both parents have to carry the gene in order for their baby to be at risk of having the disease.
The risks of inheritable diseases overlap from one ethnic or geographic group to another. Genes get passed around among the various populations whenever the parents are from different ethnic groups. But you can roughly gauge whether your ancestry puts you at an elevated risk of carrying genes for certain diseases.
Some people don’t know very much about their ethnic background or family medical history, perhaps because they were adopted or haven’t had much contact with their biological families. If this is your situation, don’t worry. Keep in mind that the chances of both you and your partner carrying a gene for a particular disorder are extremely low.
OTHER TESTS FOR THOSE OF JEWISH DESCENT
Here’s a list of genetic disorders for which screening is available to couples of Jewish descent (although at this time, the American Congress of Obstetricians and Gynecologists recommends only Tay-Sachs, cystic fibrosis, Canavan disease, and familial dysautonomia testing):
· Tay-Sachs
· Cystic fibrosis
· Canavan
· Familial dysautonomia
· Gaucher
· Neimann-Pick
· Mucolipidosis IV
· Fanconi anemia
· Bloom syndrome
· Familial hyperinsulinemia
· Lipoamide dehydrogenase deficiency
· Maple syrup urine disease
· Glycogen storage disease 1a
· Nemaline myopathy
· Usher syndrome
Although recommended for the Ashkenazi Jewish population, these tests are available to everyone.
Considering the physical exam
At your first prenatal visit, your practitioner examines your head, neck, breasts, heart, lungs, abdomen, and extremities. She also performs an internal exam. During this exam, your practitioner evaluates your uterus, cervix, and ovaries and performs, if due, a Pap test (cervix cancer and pre-cancer screening). Also, in many (if not all) states, screening for sexually transmitted infections (STIs) is mandated by law. If your state isn’t one in which this screening is required, be sure to let your physician know if you feel you also should be tested for the possibility of sexually transmitted diseases.
After the exam, you and your practitioner will discuss the overall plan for your pregnancy and talk about any possible problems. You can also discuss what medications you can take while you’re pregnant, when you should call for help, and what tests you can expect to undergo throughout your pregnancy.
Eyeing the standard tests
Brace yourself: You’re probably going to be stuck with a needle and have to pee in a cup during your first prenatal visit. Here’s a look at the standard procedures, including blood and urine tests.
Get ready for the prick: Blood tests
On your first prenatal visit, your practitioner will draw your blood for a bunch of standard tests to check your general health as well as to make sure you’re immune to certain infections. The following tests are routine:
· A standard test for blood type, Rh factor, and antibody status: The blood type refers to whether your blood is type A, B, AB, or O and whether you’re Rh-positive or Rh-negative. The antibody test is designed to tell whether special blood-group antibodies to certain antigens (like the Rh antigen) are present. (See Book 6, Chapter 2 for more about the Rh factor and the implications of blood incompatibilities.)
· Complete blood count (CBC): This test checks for anemia, which refers to a low red blood cell count. It also checks your platelet count (a component of blood important in clotting).
· VDRL or RPR: These tests check for syphilis. They’re very accurate, but sometimes they produce a false positive result if the patient has other conditions, such as lupus or antiphospholipid antibody syndrome (see Book 6, Chapter 3). However, these kinds of false positive results are usually weakly positive. These tests are nonspecific, so in order to confirm the diagnosis of syphilis, another, more specific blood test should be performed. Because it’s essential that syphilis be adequately treated, make sure you receive a test. In fact, most states require it. Unfortunately, the incidence of syphilis is on the rise in the United States.
· Hepatitis B: This test checks for evidence of the hepatitis viruses. These viruses come in several different types, and the hepatitis B virus can be present without producing actual symptoms. In fact, some women are diagnosed only during a blood test, such as the one performed during pregnancy.
· Rubella: Your practitioner also checks for immunity to rubella (also called German measles). Most women have been vaccinated against rubella or, because they’ve had the illness in the past, their blood carries rubella antibodies, which is why contracting German measles during pregnancy is so rare. Most practitioners test to see that the mother is immune to rubella during the very first prenatal visit. Any woman who isn’t immune is counseled to be careful to avoid contact with anyone who has the illness. A practitioner also advises these women to get vaccinated against rubella soon after they deliver so that they aren’t susceptible in subsequent pregnancies.
· HIV: Some states require that healthcare providers routinely ask whether you want to be checked for HIV, the virus that causes AIDS. Because medication is available to reduce the risk of transmission to the baby as well as to slow disease progression in the mother, being aware of your HIV status is very important. A doctor can usually perform this test at the same time as the other prenatal blood tests.
Doctors sometimes need to perform other tests during your first prenatal visit. These additional tests include the following (head to Book 6, Chapter 3 for information on many of the conditions and illnesses identified in this list):
· Glucose screen: You usually get this test around 24 to 28 weeks, but your doctor may administer it in the first trimester if you’re at a high risk of developing gestational diabetes.
· Varicella (chickenpox): Your doctor may conduct this test to check for immunity to varicella. If you’re unsure whether or not you’ve had chickenpox or you know that you haven’t had it, let your practitioner know so you can be tested for immunity.
· Toxoplasmosis: Sometimes a doctor administers a test in order to check for immunity to toxoplasmosis, a type of parasitic infection. In the United States, testing for toxoplasmosis isn’t considered routine unless you’re at a higher risk for contracting it. For example, if you have an outdoor cat and you’re the one who changes the litter box, your practitioner is likely to send off a test to check for past or recent exposure. If you’re in France, where the incidence of toxoplasmosis is much higher, your practitioner will probably recommend that you be tested.
· Cytomegalovirus (CMV): Testing for CMV, a common childhood infection, isn’t routine during pregnancy. However, if you have a lot of contact with school-age children who may have the infection, your practitioner may suggest you have this test. As with toxoplasmosis, the blood test looks for evidence of past or recent infection.
· Vitamin D: Vitamin D deficiency is more common in pregnancy than previously thought. In fact, it’s quite common in certain high-risk groups, including vegetarians, women who have limited sun exposure, and ethnic minorities. Babies born to vitamin D-deficient moms are also at risk of vitamin D deficiency. When severe, this can lead to problems in the development of the bones in the newborns. A simple blood test for 25-OH-D can indicate vitamin D status. If you do find that you’re vitamin D-deficient, your provider may recommend a supplement (in addition to your prenatal multivitamin).
· Lead screening: Prenatal lead exposure has been linked to a variety of adverse outcomes for mom and baby. Recently, the Centers for Disease Control and Prevention (CDC) and the American Congress of Obstetricians and Gynecologists (ACOG) have addressed the issue of screening for elevated lead levels in maternal blood. Although they don’t recommend routine screening, they do suggest evaluating pregnant women for risk factors and testing those women at high risk. Some risk factors for lead exposure include the following:
· Recent emigration from a place where lead contamination is high
· Living near a high source of lead, such as land mines or battery recycling plants
· Being in close contact with someone who works with lead
· Eating nonfood substances such as soil or paint containing lead or glazed ceramic pottery (pica is a disorder where individuals eat nonnutritive substances)
· Using home remedies or certain therapeutic herbs traditionally used by East Indian, Indian, Middle Eastern, West Asian, and Hispanic cultures that may be contaminated with lead
· Having a history of previous lead exposure or living with someone identified as having an elevated lead level
If testing shows you have a high lead level, you need to speak with your doctor about treatment. A diet containing adequate amounts of calcium, iron, zinc, and vitamins C, D, and E is also known to help decrease lead absorption.
Take a quick trip to the bathroom: Urine tests
Each time you visit your practitioner during your pregnancy, including the first prenatal visit, you’re asked to give a sample of urine. Your practitioner uses the urine sample to check for the presence of glucose (for a possible sign of diabetes) and protein (for evidence of preeclampsia) and to screen for a UTI.
Sneak the first look at your baby: Ultrasound
An ultrasound uses sound waves to create a picture of the uterus and the baby inside it. Ultrasound examinations don’t involve radiation, and the procedure is safe for both you and your baby. Your practitioner may suggest that you undergo a first-trimester ultrasound exam. Often, this ultrasound is performed transvaginally, which means that a special ultrasound probe is inserted into the vagina. The advantage to this technique is that the probe, or transducer, is closer to the fetus, so a much clearer view is attained than with a standard transabdominal ultrasound examination.
Some women worry that a probe inserted into the vagina could harm the baby. Although understandable, you don’t need to worry. The probe is completely safe.
The following are evaluated during a first-trimester ultrasound exam:
· The accuracy of your due date: An ultrasound can show whether the fetus is any larger or smaller than the date of your last menstrual period would suggest. An ultrasound in the first trimester is actually more accurate than a later ultrasound in confirming or establishing your due date.
· Fetal viability: By five to six weeks into your pregnancy, an ultrasound can detect a fetal heartbeat. After a fetal heartbeat has been identified, the risk of miscarriage drops significantly (to about 3 percent). Prior to five weeks, the fetus itself may not be visible; instead, the ultrasound may show only the gestational sac.
· Fetal abnormalities: Although a complete ultrasound examination to detect structural abnormalities in the fetus usually isn’t performed until about 20 weeks, some problems may already be visible by 11 to 12 weeks. Much of the brain, spine, limbs, abdomen, and urinary tract structures can be seen with a transvaginal ultrasound. In addition, the presence of a thickening behind the neck of the fetus (known as increased nuchal translucency) may indicate an added risk for certain genetic or chromosomal conditions (see Book 2, Chapter 2).
· Fetal number: An ultrasound shows whether you’re carrying more than one fetus. In addition, the appearance of the membrane separating the babies, as well as the placental locations, helps indicate whether the babies share one placenta or have separate placentas. Book 6, Chapter 1 goes into greater detail about this topic.
· The condition of your ovaries: An ultrasound can reveal abnormalities or cysts in your ovaries. Sometimes an ultrasound shows a small cyst, called a corpus luteal cyst, which forms at the site where the egg was released. Over the course of three or four months, it gradually goes away. Two other types of cysts, called dermoid cysts and simple cysts, are unrelated to the pregnancy and may be found incidentally during an ultrasound exam. Whether removal of these types of cysts is necessary and when they should be removed depends on the size of the cyst and any symptoms you may be having.
· The presence of fibroid tumors: Also called fibroids, these are benign overgrowths of the muscle of the uterus. Book 6, Chapter 3 goes into more details about these.
· Location of the pregnancy: Occasionally, the pregnancy may be located outside the uterus, which is called an ectopic pregnancy (see the “Ectopic pregnancy” section later in this chapter for more information).
Detecting Genetic Abnormalities in the First Trimester: Your Options
With the explosion of genetic technology, there’s a whole menu of options for detecting genetic abnormalities in your baby, and many of them can be done in the first trimester. The options fall mainly into two categories: screening tests and diagnostic tests:
· Screening: A screening test collects bits of information about the developing fetus that can be used to estimate the probability that your baby has certain genetic abnormalities; the odds are usually expressed as a ratio (1/100, 1/1,000, 1/10,000, and so on). The bits of information can be substances produced by the placenta that can be measured in the mother’s blood, measurements on an ultrasound, or fragments of fetal DNA that circulate in Mom’s bloodstream.
· Diagnostic: A diagnostic test uses tiny pieces of placental tissue (chorionic villus sampling, or CVS), fetal skin cells that have flaked off the surface of the baby (amniocentesis), or fetal lymphocytes (fetal blood sampling) to directly look at the tissue to see whether the genetic makeup is normal or abnormal. CVS is the only diagnostic test performed in the first trimester.
The diagnostic tests involve checking the developing baby’s chromosomes. Chromosomes carry the genetic information (DNA) that determines what a person is like. People normally have 46 chromosomes — 23 inherited from their mother and 23 from their father. The 23 from each side are paired inside the nucleus of each human cell. Twenty-two of these pairs are autosomes, which are the chromosomes that aren’t sex-related. The 23rd pair of chromosomes are the sex chromosomes, which can be either XX (girl) or XY (boy).
Certain abnormalities in chromosome number or structure can lead to problems in the baby. For example, Down syndrome, one of the more common chromosomal abnormalities associated with severe mental retardation, may occur if the fetus has an extra copy of chromosome 21. (The condition is also known as trisomy 21, because the fetus has three copies of the chromosome.)
Amniocentesis, CVS, and other tests detect abnormalities in chromosome number and structure by yielding a karyotype, which is an enlarged picture of the individual chromosomes. In addition, if you and the baby’s father have a known risk for carrying a genetic disease that runs in your family or ethnic group (Tay-Sachs or cystic fibrosis, for example), your practitioner can use the material obtained during these procedures to test for such diseases. However, unless you’re specifically at risk for one of these rare genetic disorders, your practitioner won’t routinely administer this testing; the chromosomes are checked only for number and structure.
LOOKING AT MATERNAL AGE
In the past, women who were going to be age 35 or older at their due date were offered the chance to undergo prenatal diagnosis to check the fetal chromosomes. Age 35 was chosen as the target age because a woman’s risk of having a baby with a chromosomal abnormality increases significantly after she reaches that age. The cutoff age of 35 is somewhat arbitrary, however, and not followed in all countries. In Great Britain, for example, women are offered prenatal chromosomal testing at age 37 or after.
When nuchal translucency testing became available, the American Congress of Obstetricians and Gynecologists recommended that doctors stop using age to determine who should have a diagnostic test. The current practice is to offer every woman the same thing and allow her to choose which test or tests she wants to undergo.
Even among women at risk for a chromosomal problem, some choose not to be tested, either because they don’t want to run any risk of miscarriage associated with the test or because of their personal beliefs about terminating a pregnancy. Even if pregnancy termination isn’t something you would consider, prior knowledge of a fetus’s abnormalities can give you time to make preparations for a child who may have special needs.
Chorionic villus sampling (CVS)
Chorionic villi are tiny, budlike pieces of tissue that make up the placenta. Because they develop from cells arising out of the fertilized egg, they have the same genetic makeup as the developing fetus. By checking a sample of chorionic villi, the laboratory can see whether the chromosomes are normal in number and structure, determine the fetal sex, and test for some specific diseases (if the fetus may be at risk for these diseases).
Your doctor performs a chorionic villus sampling (CVS) by withdrawing placental tissue (containing chorionic villi) either through a hollow needle inserted through the abdomen (transabdominal CVS) or through a flexible catheter inserted through the cervix (transcervical CVS, seen in Figure 1-2), depending on where the placenta is located within the uterus and the uterus’s general shape and position. Your doctor uses ultrasound equipment as a guide as she performs the procedure. She then examines the tissue under a microscope, and the cells are cultured in a laboratory.
Illustration by Kathryn Born, MA
FIGURE 1-2: In transcervical CVS, your doctor uses a flexible catheter inserted into the cervix to withdraw a tiny amount of placental tissue, using ultrasound as a guide.
Like amniocentesis, CVS raises the risk of miscarriage slightly — about 1/1,000. Neither CVS method is riskier than the other. The person performing the test should have plenty of experience doing the procedure, and experience reduces the risk.
CVS results are typically available in seven to ten days. The main advantage that CVS has over amniocentesis is that it can provide information earlier in the pregnancy. This time factor may be important to women who feel that termination is an option if severe abnormalities are present.
If you undergo CVS and are Rh-negative, you should receive an injection of Rh-immune globulin (such as Rhophylac or Rhogam) following the procedure to prevent you from developing Rh disease (see Chapter 2 in Book 6).
Noninvasive screening in the first trimester
CVS and early amniocentesis (which is no longer recommended due to concerns about causing birth defects) are the only tests that can give definitive information about fetal chromosomes during the first trimester. There are two screening tests now available in the first trimester.
First Trimester Screen
The First Trimester Screen uses a combination of a special ultrasound measurement, called nuchal translucency, and two substances found in Mom’s blood. Eighty to 90 percent of fetuses with Down syndrome may be detected through this type of screening.
These first-trimester screening tests are usually performed between the approximate gestational ages of 10 weeks, 4 days and 13 weeks, 6 days. Here’s how they work:
· Nuchal translucency (NT): This test uses ultrasound to measure a special area behind the fetal neck. Only physicians specially trained in the procedure should conduct a nuchal translucency test. Combining measurements of nuchal translucency with blood screening tests probably increases the accuracy of these tests.
· Serum screening: Tests that check the levels of PAPP-A, a substance produced by the placenta, and hCG, a hormone in the mother’s blood, may help screen for Down syndrome in the first trimester. Usually, this blood test is done around the same time as the ultrasound to measure the nuchal translucency.
The equation to calculate the risk for Down syndrome takes into account the nuchal translucency, the two blood components mentioned previously, a measurement of the length of the embryo called the crown to rump length (CRL), and your age at your expected due date. The results come as a risk ratio — like 1/310.
· If the screening shows your chances of having a baby with Down syndrome are high, your doctor will recommend that you have a diagnostic test. CVS (see the preceding section) can be done in the first trimester, but for amniocentesis, you have to wait until the second trimester.
· If your results are good (for example, if they show that you have a low risk for Down syndrome), you may want to wait until the second trimester and have a Quad Test (see Book 2, Chapter 2). The results of this test will be integrated with the First Trimester Screen to even further refine your risk for Down syndrome. Doing the tests this way will detect almost 96 to 98 percent of fetuses with Down syndrome.
NIPS (noninvasive prenatal screening)
The newest way of screening for Down syndrome is called NIPS, or noninvasive prenatal screening. For this procedure, a sample of blood is drawn from Mom and sent to the lab, where tiny fragments of the baby’s DNA (which are normally present in small quantities in Mom’s blood) are isolated and analyzed. This method can detect about 98 to 99 percent of babies with Down syndrome.
The sample of blood can be drawn and sent anytime during pregnancy, but it’s best to do it in the first trimester so you can get the results back in time to make reproductive choices that are right for you. You can also predict the gender with this test. NIPS also detects many cases of trisomy 13 and 18 (which are disorders similar to Down syndrome, but different chromosomes are involved) but not at the same detection rate as for Down syndrome.
The original studies on NIPS were done on high-risk women (women over the age of 35, with a family history of chromosomal abnormalities, or with high-risk First Trimester Screen results), so that’s whom the test was recommended for. Recently, however, data suggests that NIPS may be useful in low-risk women too.
Recognizing Causes for Concern
In each trimester, a few things may go less than smoothly. This section describes some of the things that can happen during the first trimester of your pregnancy and what they may mean to you.
Bleeding
Early in pregnancy, around the time of your missed period, experiencing a little bleeding from the vagina isn’t uncommon. The amount of bleeding is usually less than what you’d expect with a period and lasts for only one or two days. This is called implantation bleeding, and it happens when the fertilized egg attaches to the uterus’s lining. Bleeding due to implantation isn’t a cause for concern, but many women may be confused by it and mistake it for their period.
Bleeding also may occur later in the first trimester, but it doesn’t necessarily indicate a miscarriage. About one-third of women experience bleeding during the first trimester, and the majority of them go on to have perfectly healthy babies. Bleeding is especially common in women carrying more than one fetus — and again, most go on to have normal pregnancies. Bright red bleeding usually indicates active bleeding, while dark staining usually indicates old blood that is making its way out from the cervix and vagina. Most of the time, an ultrasound exam doesn’t show any evidence of the source of the bleeding. However, sometimes a collection of blood, known as a subchorionic or retroplacental hemorrhage or collection, is visible and indicates an area of bleeding from behind the placenta. It usually takes several weeks for this blood to be reabsorbed. During this time, some dark blood continues to pass out through the cervix and vagina.
In some cases, bleeding can be the first sign of an impending miscarriage (see the next section for more information). In this case, the bleeding often accompanies abdominal cramping. However, keep in mind that the vast majority of women who experience bleeding go on to have a completely normal pregnancy.
If you notice some bleeding, let your practitioner know. If the bleeding is a small amount and not associated with a lot of abdominal cramping, it isn’t an emergency. However, if you’re bleeding heavily (much more than a period), call your practitioner as soon as you can. She may want to do an ultrasound and perform a pelvic exam to investigate the cause of the bleeding and see whether the pregnancy is still viable and located inside the uterus. Most of the time, your practitioner can do very little about the bleeding. Some doctors may suggest that you rest at home for a few days and avoid exercise and sex. No scientific data supports these instructions, but given that no really good alternatives exist, they certainly don’t hurt.
Miscarriage
The great majority of pregnancies proceed normally. But about one in five ends in early miscarriage, often before a woman even knows she’s pregnant. If a miscarriage occurs early in a pregnancy, you may mistake it for a regular menstrual period. About half the time, chromosomal abnormalities in the embryo cause the miscarriage. In another 20 percent of cases, the embryo may have structural defects that are too small to be detectable by ultrasound or pathological examination. Note: Having one miscarriage doesn’t mean that you have an increased chance of its happening again. Also, no routine everyday activities can cause a miscarriage.
Miscarriage may lead to cramping and bleeding. You may feel abdominal pains that are stronger than menstrual cramps, and you may pass fetal and placental tissue. In cases where all the tissue is passed, your practitioner doesn’t need to do anything else. Often, though, some tissue remains in your uterus, and you may need medication to encourage its passing or have a D&C (dilation and curettage) procedure, designed to empty the uterus. Your doctor dilates, or gently opens, the cervix with surgical instruments and then empties the remaining contents of the uterus with a suction device and/or a scraping of the uterus. A D&C can be performed either in the doctor’s office or in an operating suite, depending on the doctor, the gestational age, and any other important medical problems.
Sometimes, you may have no overt signs of miscarriage. Your practitioner may discover during a routine prenatal visit that the fetus is no longer alive, which is known as a missed abortion. If you have a missed abortion very early in your pregnancy, a D&C may not be necessary. But if it happens later in the first trimester, you may need to have a D&C to reduce the risk of heavy bleeding or incomplete passage of tissue. Depending on your obstetrical history and your desire to try to determine the cause of the miscarriage, you may decide to have the tissue sent for genetic analysis (to find out whether the chromosomes were normal or abnormal). Because half of all miscarriages are due to chromosomal abnormalities, it may be useful to find out whether this was the cause.
Unfortunately, most miscarriages can’t be prevented. Many, if not most, of them may simply be nature’s way of handling an abnormal pregnancy. However, having a miscarriage doesn’t mean that you can’t have a perfectly normal pregnancy in the future. In fact, even in women who have had two consecutive miscarriages, the chances are very good (about 70 percent) that the next pregnancy will be successful without any special treatment.
Any woman who experiences two or three consecutive miscarriages may have some underlying condition that can be identified and possibly treated. She should have a complete physical examination and undergo special tests to look for causes. Some women who have even one miscarriage may want to be examined. If you miscarry, discuss with your practitioner the possibility of undergoing certain tests or sending fetal or placental tissue to a laboratory for chromosomal analysis.
Ectopic pregnancy
An ectopic pregnancy occurs when the fertilized egg implants outside the uterus — in one of the fallopian tubes, the ovary, the abdomen, or the cervix. An ectopic pregnancy is a serious threat to the mother’s health. Fortunately, ultrasound has advanced to the point that it can detect ectopic pregnancies very early.
Signs of an ectopic pregnancy include vaginal bleeding, abdominal pain, pelvic pain, dizziness, and feeling faint. You may not have any symptoms, in which case your doctor identifies the condition during an ultrasound. Your doctor can treat the problem in one of several ways, depending on the location of the embryo or fetus, how far along the pregnancy is, and the symptoms you’re experiencing. Unfortunately, a doctor can’t move the embryo or fetus to the uterus so that the pregnancy can continue as normal.