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Understanding Pregnancy and Childbirth

John Wiley & Sons

Chapter One

Something as natural as being able to have a baby cannot be taken for granted. Planning ahead for childbirth is important. The body cannot be expected to perform on demand without preparation. In the same way that an athlete strengthens her body to run a grueling marathon with a plan of gradual physical training, a woman can ready her body so that pregnancy will be as comfortable and healthy as possible. Women are starting to recognize that planning ahead and preserving fertility are important. Older women facing a first pregnancy often ask us about the possible effects of a long-ago abortion or an infection. Concern and even fear are common.

Women are having children later in life. The number of births in general is going up, rising 3 percent in the year 2000. Fertility rates have increased by 1 to 2 percent, and there has been an increase in the number of twin pregnancies, reflecting the new reproductive technologies. There has been a rise in the birthrate among thirty- to forty-five-year-old women-women who were once thought to be beyond childbearing years. Births to women in their forties to early fifties were up again in the year 2000. The reason for this is twofold: Women are marrying later and waiting to have children until their educations are completed and their careers established; in addition, 37 million of thepostwar babies, the so-called baby boomers, are now older women, whose sheer numbers add clout to any changes that they as a group decide upon. Also, affluence affords many older women access to the advances of reproductive technologies, giving them an opportunity to bear children later in life. In the past, this was not possible.

In these times of women having children later, it has become even more important for you to take care of yourself at an early age. Active participation in your health and well-being is important to maintain fertility later in your life. In our complex society, many factors may affect your future childbearing. They include environmental hazards such as X rays; chemical pollutants in air, water, and food; smoking; and exposure to prescription and nonprescription drugs. Exposure to various illnesses such as rubella and toxoplasmosis can harm a developing fetus. By being informed, you can avoid many potential threats and minimize the impact of possible dangers.

The information in this chapter is intended to give you the best possible chance of having a healthy baby. We will discuss such diverse important areas as genetics, medical history, work environment, medications, eating, and exercises. Planning ahead for a healthy child will help you protect your fertility until the time is right for childbearing and will help you prepare your body and mind once you are ready for pregnancy. Planning ahead will help you get pregnant and help get your baby off to a healthy head start. Years ago not many women thought of having a baby after age thirty-five, but twenty years ago women didn't run twenty-six-mile marathons either. With the right knowledge, the right game plan, and the right care and training, both marathons and healthy pregnancies have become a reality for more women today than ever before.

PRECONCEPTIONAL CARE

Before you become pregnant or stop using birth control, you can begin to maintain a healthy lifestyle, which will help you have a healthier baby and a healthier pregnancy. This includes eating right, exercising, and avoiding alcohol, cigarettes, and exposure to harmful drugs and chemicals. Early medical care and a checkup are also important. All this is part of preconceptional, or prepregnancy, care, ensuring your good health before you become pregnant. Many women do not know they are pregnant until five, six, or even eight weeks after they have conceived. Those early weeks may be some of the most important for the baby because during that time the organs form. Certain substances, such as alcohol, tobacco, chemicals, and some medications, can interfere with that growth. Likewise, medical conditions such as diabetes or high blood pressure should be under special supervision before a woman becomes pregnant.

You should discuss your plans for pregnancy with your doctor. This provides a chance for you to get advice on any questions or concerns you might have. A doctor may also offer suggestions based on your special needs. Women with diagnosed medical problems such as diabetes and anemia have an even greater need for accurate medical advice prior to pregnancy. Find out exactly what the risks are to you and your unborn child, what you can do to reduce them, and what choices you face for risks that can't be entirely predicted or controlled.

Components of Preconceptional Care

The main components of preconceptional care are the same as those of prenatal care: assessing risk factors, promoting good health, and obtaining any necessary medical and psychosocial treatment. The anchor of all other preconceptional care activities is a comprehensive assessment of the risk you and your family carry for a poor pregnancy. You and your doctor can conduct such a comprehensive risk assessment during a special preconceptional visit or as part of a visit for other purposes. It consists of a complete history, a physical exam, and some laboratory tests. You and your physician will both review your health status, identifying any risks for a poor pregnancy outcome, and produce a plan to reduce those risks, revising it later if necessary.

In addition, you should undertake activities designed to promote good health in general. Table 1.1 lists the factors the Expert Panel on the Content of Prenatal Care identified as being important in evaluating preconceptional health. Table 1.2 lists the laboratory tests that may be valuable. Your doctor evaluates preconceptional care and recommends tests based on their potential to improve not only your health but that of your future child as well. Some tests are of little value to you before pregnancy but are important after conception. (They will be discussed in chapter 7.) Others are valuable during the early first trimester of pregnancy, but since many women do not have prenatal care until the second trimester, those should be performed at the preconception visit. For example, such risks as susceptibility to rubella should be identified prior to pregnancy. Your physician can guide you as to which laboratory tests are important for you.

Infectious Risks

When an infection occurs, for the most part, pregnant women have a normal immune system. While some infectious conditions may have only minor or no effects on a pregnant woman, the effects on the fetus can be devastating. Conversely, potentially serious infections may have little or no effect on the fetus.

HIV/AIDS

Frequency of HIV-human immunodeficiency virus-infection among women varies greatly among different population groups. Heterosexual women represent the fastest-growing group of newly diagnosed HIV-positive cases. Although recent studies have shown a decline in the incidence of HIV in high-risk populations, such as those who use IV drugs, identification of HIV-positive pregnant women has become extremely important. In 2001 the U.S. Public Health Service updated the 1995 guidelines for routine AIDS counseling and voluntary testing of all pregnant women. It is now customary at your first prenatal visit for your obstetrician to request a test for the AIDS virus. The reason for this is twofold. First, HIV-positive women are at risk for many different infections, which could put their lives and the lives of their unborn children at risk, and there are now treatments that can minimize the risk of developing such infections. Second, medicines, such as zidovudine (ZDV), have been developed that can fight the AIDS virus. ZDV can be administered to women before and during labor and can be given to babies after birth to prevent children from developing this disease. In recent studies, HIV-positive women were treated with ZDV before delivery, and the babies were given ZDV after birth. As a result, the chance of a baby developing AIDS was reduced to less than 3 percent. Having a C-section, instead of a vaginal delivery, may also reduce the risk of transmitting the virus to the baby. Given this new therapy, pregnancies may be safer in this expanding population of patients with AIDS.

Hepatitis B (HB) and Hepatitis C (HC)

About 0.3 percent of all adults in the United States are chronic hepatitis B carriers. Approximately 300,000 new cases of HB occur annually. Acute HB occurs in 1 to 2 per 1,000 pregnancies, and chronic HB occurs in 5 to 15 of every 1,000 pregnancies. An estimated 18,500 births occur among these women annually. Without the HB vaccine, approximately 4,300 newborns would acquire HB infection from these women each year. Unless treated, about 1 percent of infected infants will develop a fatal infection, and 85 percent to 90 percent will become chronic HB carriers.

To prevent newborn HB infection, doctors must first recognize the mother's infection. Then they can immunize and administer HB immune globulin promptly after delivery. Screening during pregnancy can identify positive cases.

Women at substantial risk of having or acquiring the HB virus include those who have had sexual contact with HB-infected partners, users of illicit injectable drugs, prostitutes, institutionalized women, those with tattoos, and certain immigrant groups, including Southeast Asians. Those with an ongoing risk of acquiring HB infection should have a preventive vaccination.

HB screening is now legally required of all pregnant women in many states. It makes sense to obtain a screening prior to pregnancy.

Hepatitis C (HC) appears to affect as much as 0.6 percent of the pregnant population, and the risk factors are similar to those for HB. Unlike HB, there is no vaccine to prevent infection and no treatment to offer pregnant women to reduce the risk of transmission to the baby. Pregnant women with HC should not breast-feed because there is a 2 to 3 percent risk that the virus can be transmitted this way. Approximately 7 to 8 percent of pregnant women with HC will produce offspring with HC infection.

Rubella (German Measles)

A pregnant woman infected with German measles, particularly during the first sixteen weeks, risks spontaneous abortion, stillbirth, or a baby with congenital rubella syndrome. The incidence of congenital rubella has declined by more than 99 percent since 1969, the year the rubella vaccine was licensed.

All women should be tested for rubella immunity. If you had rubella as a child, you are not necessarily immune as an adult, so routine susceptibility testing should be conducted. Most studies carried out during the early 1980s found that 10 to 20 percent of women of childbearing age had no immunity to rubella. Women considered susceptible to rubella should receive the vaccination prior to conception and then avoid pregnancy for three months. Should conception occur soon after vaccination, however, there is not a great risk of infection from the vaccination.

Toxoplasmosis

Toxoplasmosis is an infection caused by a one-cell parasite named toxoplasma gondii. It can be found in the feces of infected cats and in raw or uncooked meats. Foods that are in contact with these contaminated meats can also be infected. It is not found in raw fish, so fear not, sushi lovers!

About one-third of adult women in the United States have antibodies to toxoplasmosis; the remainder may be at risk for a primary infection during pregnancy, which can result in fetal infection. If a pregnant woman is infected during the first or the second trimester, chances are greater that the fetus will be severely affected than if the woman is infected during the third trimester. Although earlier exposure in the pregnancy has more severe consequences, the actual risk of fetal infection is much less in the earlier trimesters.

If preconceptional testing shows that you lack immunity, you should be advised about the proper cooking of meat and during pregnancy avoid close contact with cats, cat litter, or soil that may contain cat feces.

Acute infection in an adult is often subtle. Symptoms, when present, generally are nonspecific and include fatigue, swollen glands, and fever.

If symptoms develop during pregnancy, prior testing can help your physician identify whether an acute infection is due to toxoplasmosis. If repeated testing during pregnancy shows the presence of toxoplasmosis antibodies in a woman who previously had negative antibodies, then acute infection is indicated. In the absence of such prior information, the interpretation of tests obtained during pregnancy may be confusing. Labs in the United States can now pinpoint the time of exposure to the parasite quite accurately, so that women can be adequately advised. Screening of those women who own or have regular contact with cats, especially outdoor cats, is very important. Probably all women considering pregnancy should be screened.

Fifth Disease

Fifth disease is usually a childhood illness caused by a virus named parvovirus B19. Children who get infected have a rather mild illness, characterized by very red cheeks (slapped cheeks), and they completely recover. Adults who get exposed to this virus often have no symptoms at all. Most adults already are immune to this virus (over 60 percent) and therefore need not worry. When outbreaks of this virus occur (usually in the spring), around 50 percent of people who are exposed and not immune will catch this virus. Typically, the virus can be transmitted five to ten days before the appearance of the rash. If pregnant women were to seroconvert (become infected with parvovirus B19), up to one-third of them would infect the fetus, according to some studies. If fetal infection occurs, there is a small risk of fetal loss (2 to 9 percent), and it may cause a condition known as hydrops fetalis. Long-term development appears to be normal in the fetuses with congenital parvovirus when the fetus does survive. Your doctor has blood tests available that can check your immunity to this virus, should you be exposed, and can test to see if you have become infected.

Varicella Zoster Virus (Chicken Pox)

Most women of childbearing age are immune to chicken pox. Infection during pregnancy is quite rare (0.4 to 0.7 per 1,000 women). If a non-immune pregnant woman develops chicken pox within the first half of her pregnancy, there is a small risk of major birth defects (around 2 percent).

Continues...

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Excerpted from Understanding Pregnancy and Childbirth by Sheldon H. Cherry Douglas G. Moss Excerpted by permission.
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