Tutoring at home

Childbirth is the period from the onset of regular uterine contractions until expulsion of the placenta. The process by which this normally occurs is called labor—a term that in the obstetrical context takes on several connotations from the English language. According to the New Shorter Oxford English Dictionary (1993), toil, trouble, suffering, bodily exertion, especially when painful, and an outcome of work are all characteristics of labor and thus implicated in the process of childbirth. Such connotations all seem appropriate to us and emphasize the need for all attendants to be supportive of the laboring woman’s needs, particularly in regard to effective pain relief.
At Parkland Hospital in 2003, only 53 percent of 12,139 women with singleton cephalic presentations at term had a spontaneous labor and delivery. The remainder had ineffective labor requiring augmentation (29 percent) or other medical and obstetrical complications requiring induction of labor. It seems excessive to consider almost 50 percent of parturients as “abnormal” because they did not spontaneously labor and deliver. Hence, the distinction between normal and abnormal is often subjective. This high prevalence of labor abnormalities, however, can be used to underscore the importance of labor events in the successful outcome of pregnancy.

Practitioners providing routine health maintenance for reproductive-aged women have the best opportunity to provide preventive counseling. Gynecologists, internists, family practitioners, and pediatricians can do so at the annual examination. The occasion of a negative pregnancy test is a good time for counseling. Jack and associates (1995) administered a comprehensive preconceptional risk survey to 136 women who had a negative pregnancy test in an ambulatory general practice clinic. Almost 95 percent of these women reported at least one problem that could affect a future pregnancy. These included medical or reproductive problems (52 percent), a family history of genetic diseases (50 percent), increased risk of contracting HIV (30 percent), increased risk of contracting hepatitis B and use of illegal substances (25 percent), alcohol use (17 percent), and nutritional risk (54 percent).
Basic preconceptional advice regarding diet, alcohol use, smoking, illicit drug use, vitamin intake, exercise, and other behaviors can be provided by the primary care provider, including the obstetrician-gynecologist. Medical records should be obtained and reviewed. Counselors should be knowledgeable about relevant medical diseases, prior surgery, reproductive disorders, or genetic conditions, and must be able to interpret data and recommendations provided by other specialists. The practitioner who is uncomfortable providing counseling should refer the woman or couple to a counselor with special expertise.

Birth defects are currently the leading cause of infant mortality and account for 20 percent of all infant deaths. These defects can be avoided with three types of prevention strategies. The preferred strategy is primary prevention—avoidance of causal factors—which is becoming possible for more congenital diseases as their etiologies are discovered. Secondary prevention—identifying and terminating affected pregnancies—is an alternative strategy for single-gene disorders and other defects that cannot be prevented. Surgical correction of structural defects is one type of tertiary prevention, but it is not possible for most genetic disorders. The benefits of preconceptional counseling usually are measured by comparing the incidence of new cases before and after the initiation of a counseling program. Some examples of congenital conditions that clearly benefit from counseling include neural-tube defects, phenylketonuria, Tay-Sachs disease, and the thalassemias.
Neural-Tube Defects (NTDs)
The incidence of these defects is 1 to 2 per 1000 live births, and they are second only to cardiac anomalies as the most frequent structural fetal malformation. Some NTDs are associated with a specific mutation in the methylene tetrahydrofolate reductase gene (677C T), the adverse effects of which appear to be largely overcome by periconceptional folic acid supplementation (Ou and associates, 1996; van der Put and colleagues, 1995). The Medical Research Council on Vitamin Study Research Group (1991) conducted a randomized double-blind study of preconceptional folic acid therapy at 33 centers in seven European countries. Women with a previous affected child who took supplemental folic acid before conception and throughout the first trimester reduced their NTD recurrence risk by 72 percent. Perhaps more importantly, because 90 to 95 percent of NTDs occur in families with no prior history, Czeizel and Dudas (1992) subsequently showed that supplementation reduced the a priori risk of a first NTD occurrence.
Phenylketonuria (PKU)
This disorder is an inborn error of phenylalanine metabolism. It is an example of a disease in which the fetus is not at risk to inherit the disease but may be damaged by the effects of maternal genetic disease. For such conditions, preconceptional counseling regarding strategies to improve the intrauterine environment constitutes primary prevention and may significantly reduce fetal morbidity. Individuals with PKU who eat an unrestricted diet have abnormally high blood phenylalanine levels. This amino acid readily crosses the placenta and can damage developing fetal organs, especially neural and cardiac tissues. With preconceptional counseling and adherence to a phenylalanine-restricted diet before pregnancy, the incidence of fetal malformations is dramatically reduced (Guttler and colleagues, 1990; Koch and associates, 1990).
The Maternal Phenylketonuria Collaborative Study evaluated the effectiveness of preconceptional care in preventing PKU-related fetal defects (Rouse and co-workers, 1997). Almost 300 women with PKU began a low-phenylalanine diet before pregnancy. Compared with infants whose mothers had poor dietary control, infants of women achieving good control had a lower incidence of microcephaly (6 versus 15 percent), neurological abnormalities (4 versus 14 percent), and cardiac defects (none versus 16 percent). The proportion of women treated preconceptionally increased from 7 to 51 percent from 1984 to 1994 (Platt and colleagues, 2000).
Tay-Sachs Disease
This disease is a severe, autosomal-recessive neurodegenerative disorder that leads to death in childhood. The effectiveness of preconceptional counseling in reducing genetic disease has been most clearly demonstrated in Tay-Sachs disease. In the early 1970s, there were approximately 60 new cases in the United States each year, primarily in individuals of Jewish heritage. An intensive worldwide campaign was initiated to counsel Jewish men and women of reproductive age, to identify carriers through genetic testing, to provide prenatal testing—secondary prevention—for high-risk couples, and even to help heterozygote carriers choose unaffected mates—primary prevention! The outcome of this initiative has been monitored by the National Tay-Sachs Disease and Allied Disorders Association (Kaback and colleagues, 1993). Within 8 years of its inception, nearly 1 million young adults around the world had been tested and counseled, and the incidence of new Tay-Sachs cases has plummeted to only about five new cases per year. Currently, most new cases are in the non-Jewish population.
Thalassemias
These disorders of globin-chain synthesis are the most common single-gene disorders worldwide. Approximately 200 million people carry a gene for one of these hemoglobinopathies (Benz, 2001). Hundreds of mutations have been identified that cause several important thalassemia syndromes. Some of these could be avoided by both primary and secondary prevention (Fucharoen and associates, 1991; Wong, 1985). In endemic areas such as Mediterranean countries, counseling and other prevention strategies have reduced the incidence of new cases by at least 80 percent (Angastiniotis and Modell, 1998). Experiences with a long-standing counseling program aimed at Montreal high school students at risk were summarized by Mitchell and colleagues (1996). Over a 20-year period, 25,274 students of Mediterranean origin were counseled and tested for -thalassemia. Within a few years of initiating the preconceptional program, all high-risk couples who requested prenatal diagnosis had already been counseled, and no affected children have been born since that time.

Diabetes Mellitus
Because maternal and fetal pathology associated with hyperglycemia is well known, diabetes is the prototype of a condition for which preconceptional counseling is beneficial. Many of these complications can be avoided if conception occurs when glucose control is optimal (Jovanovic and colleagues, 1981). Such control requires either that glucose levels be chronically well regulated—always a goal, but difficult to achieve—or that the woman make necessary changes before attempting conception. Preconceptional counseling can educate her about risks and provide a program designed to reduce them (Bernasko, 2004).
The utility of preconceptional counseling in preventing diabetes-related complications at all stages of pregnancy has been confirmed. Importantly, all studies showed that counseling is associated with significantly fewer malformations.
Dunne and co-workers (1999) reviewed the impact of preconceptional counseling on other diabetes-related neonatal morbidity. Women who received counseling sought prenatal care earlier, had lower hemoglobin A1c levels, and were less likely to smoke during pregnancy. Their outcomes were compared with those of a cohort of women who did not receive such counseling. Of the women who received counseling, none were delivered before 30 weeks compared with 17 percent in the uncounseled group. In addition, the counseled women had fewer macrosomic infants—25 versus 40 percent; they had no growth-restricted infants compared with 8.5 percent; they had no neonatal deaths compared with 6 percent; and their infants had 50 percent fewer admissions to the intensive care nursery—17 versus 34 percent.
Preconceptional counseling also reduces obstetrical complications and health care costs in diabetic women. In a prospective multicenter observational trial from five Michigan centers, Herman and colleagues (1999) confirmed these benefits. They reported that diabetic women who received preconceptional counseling reported for prenatal care 3 weeks earlier than uncounseled women; they had lower hemoglobin A1c levels; they were significantly less likely to require antepartum hospitalization for diabetes control—8 versus 68 percent; and they had significantly fewer hospitalization days—4.5 versus 15.7. Counseled women also had fewer episodes of hypoglycemia and diabetic ketoacidosis; they had no hypertensive complications; and their postpartum stay was 2 days shorter than that of uncounseled women. These improved outcomes were associated with savings of $34,000 in direct medical costs per patient who received counseling.
Epilepsy
Women with epilepsy are two to three times more likely to have infants with structural anomalies than unaffected women (Chang and McAuley, 1998; Wide and associates, 2004). Some reports indicate that epilepsy itself increases the incidence of congenital anomalies, independent of the effects of antiseizure medication. In a recent study, however, Holmes and colleagues (2001) compared 509 epileptic women who took antiseizure medication during pregnancy to 606 who did not. They found that only infants exposed to anticonvulsant medications had an increased incidence of structural anomalies. Fetuses exposed to one drug had significantly fewer malformations than those exposed to two or more drugs—21 versus 28 percent. By contrast, the incidence of defects in fetuses of epileptic mothers who did not take medication was only 8.5 percent—the same as in fetuses of women without seizure disorders. Preconceptional counseling usually includes recommendations to switch to monotherapy with the least teratogenic medication (Adab and colleagues, 2004; American Academy of Neurology, 1998). The risks of antiseizure medication are described in detail in Chapter 14 (see Anticonvulsant Medications).
Epileptic women also are advised to take supplemental folic acid. Biale and Lewenthal (1984) performed a retrospective case-control study to evaluate effects of periconceptional folate supplementation in women taking anticonvulsants. Although 10 of 66 (15 percent) unsupplemented pregnancies resulted in offspring with congenital malformations, none of 33 neonates of supplemented women had anomalies. Depending on the history, a trial period without anticonvulsants also may be recommended.
Other Chronic Diseases
Cox and co-workers (1992) reviewed pregnancy outcomes of 1075 high-risk women who received preconceptional counseling. If they received counseling, 240 women with hypertension, renal disease, thyroid disease, asthma, and heart disease had significantly better outcomes than previous pregnancies. Indeed, 80 percent of those counseled gave birth to a normal infant compared with only 40 percent in the previous uncounseled gestation.

To be effective, counseling about potential pregnancy risks and strategies to prevent them must be provided before conception. By the time most women realize they are pregnant—1 to 2 weeks after the first missed period—the fetal spinal cord has already formed and the heart is beating (Moore, 1983). Many prevention strategies, for example, folic acid to prevent neural-tube defects, are ineffective if initiated at this time. The Centers for Disease Control and Prevention (1999) estimate that up to half of all pregnancies are unplanned, and there is evidence that these may be at greatest risk.
Adams and colleagues (1993) conducted a population-based survey of almost 12,500 women in four states and found that women with unintended pregnancies were more likely than those with planned pregnancies to have an indication for preconceptional counseling. Hellerstedt and co-workers (1998) surveyed nearly 7200 pregnant women and found that women with unintended pregnancies were more likely to have high-risk behaviors. Jack and associates (1995) administered a comprehensive risk survey to 136 women at the time of a negative pregnancy test. They found that (1) the majority did not want to be pregnant, (2) half reported a medical or reproductive risk that could adversely affect pregnancy, (3) half reported a genetic risk, and (4) one fourth reported risks for human immunodeficiency virus (HIV) and hepatitis B infection or alcohol or recreational drug use. Unwanted pregnancies are particularly common in the unmarriedurban poor (Besculides and Laraque, 2004).
An important measure of the effectiveness of preconceptional counseling is, therefore, its influence in reducing the number of unintended pregnancies. Moos and colleagues (1996) instituted a preconceptional care program for reproductive-aged women who visited a health department clinic and then also studied 1378 women who sought prenatal care. They reported that the 456 women who had preconceptional counseling had a 50-percent greater likelihood of describing their pregnancies as intended compared with that of 309 women with health care but no counseling, and a 65-percent greater likelihood compared with that ofwomen with no health care prior to pregnancy.

In the early part of the 20th century, women with medical problems were often unable to conceive or were advised not to. Discoveries such as insulin and the development of effective antihypertensive medications subsequently made it possible for many of these women to contemplate pregnancy. Obstetrical care of women with medical problems during this time dealt almost exclusively with protecting maternal health, as little was known about pathological influences on fetal development. In the 1960s, research began to focus on the pathophysiology of pregnancy and perinatal outcome. As a result, prenatal care was gradually extended to include fetal concerns, and interest in perinatal research increased dramatically. The etiologies of many maternal and fetal conditions were determined, and research also clarified the genetic origins of many diseases. At the same time, effective contraception was developed, allowing women to postpone pregnancy and limit family size while striving to optimize perinatal outcome. The focus of obstetrical care thus changed once again, from treating maternal and fetal diseases to predicting and preventing them.
In 2000, the Public Health Service released Healthy People 2010, a guide for the second nationwide preventive medicine program. The major goals are to increase the quality and years of healthy life and to eliminate health disparities between individuals. More specifically, it strives to improve the health and well-being of women, infants, children, and families.
Preconceptional counseling can play a major role in achieving these goals. As stated in the Department of Health and Human Services report on the program: “Preconceptional screening and counseling offer an opportunity to identify and mitigate maternal risk factors before pregnancy begins.” For example, the two leading causes of death in the first year of life—birth defects and disorders caused by preterm birth—can both be significantly reduced or eliminated by the preconceptional initiation of specific preventive strategies. Morbidity caused by a variety of factors, including uncontrolled maternal disease, environmental exposures, and nutritional deficiencies, also can be prevented by preconceptional care. Furthermore the intrauterine fetal environment has a tremendous impact on the health and well-being of the adult that fetus will become—the Barker hypothesis (Barker, 1994). Thus, optimizing pregnancy conditions and outcomes has long-term health impacts that are only beginning to be apparent. The 1989 Public Health Service Expert Panel on the Content of Prenatal Care rightfully concluded: “The preconceptional visit may be the single most important health care visit when viewed in the context of its effect on pregnancy.”

Myometrial cells have developed a unique system of regulatory pathways that rely not only on estrogen and progesterone receptors but also on a variety of cell surface receptors that can directly regulate the contractile state of the cell. The three major classes of cell surface receptors are the G-protein–linked, ion channel–linked, and enzyme-linked. Multiple examples of each class of receptors have been identified in human myometrium, and examples of each class appear to be modified during the phases of parturition. Most of these heptahelical receptors are associated with the activation of adenylyl cyclase. Other heptahelical receptors in myometrium, however, are more commonly associated with G-protein–mediated activation of phospholipase C, which will lead to increased [Ca2+]i and myometrial cell contraction. Many G-protein–coupled receptors that participate in regulation of myometrial activity have been characterized. These were reviewed recently by Lopez (2003).
Ligands for the heptahelical receptors include neuropeptides, hormones, and autacoids. Many of these are available to the myometrium during pregnancy in high concentration by several routes: from maternal blood (endocrine), contiguous tissues or adjacent cells (paracrine), or direct synthesis in the myometrial smooth muscle cells (autocrine) (Fig. 6–16). It is important to note that the myometrial response to a hormone can change during the course of pregnancy. Thus, it is conceivable that hormone action on the myometrium is regulated at several levels, including the expression of the heptahelical receptor, its associated G-proteins, or the effector proteins in the plasma membrane. Specifically, the imposition of quiescence (activation of adenylyl cyclase) or the facilitation of contractions (activation of phospholipase C and increased [Ca2+]i) may in some cases be regulated by the same hormone.