Peter S. Bernstein, MD, MPH


December 27, 2002

Prenatal care is proffered by many policy makers as the cure for the problem of low birth weight and preterm birth. If only more pregnant women had access to prenatal care, the logic goes, fewer babies would be born prematurely. Unfortunately, prenatal care has never been shown to have an impact on the occurrence of preterm delivery or low birth weight. Studies that purport to demonstrate this are flawed in that they lack appropriate control groups. These studies compare women who seek prenatal care with those who do not, and these are not comparable groups. In fact, in the United States, the number of premature births has grown over the last decade from 10.6% in 1990 to 11.6% in 2000.[1] All this despite growing evidence of more women having access to prenatal care as demonstrated by larger numbers of women enrolling in prenatal care early in their pregnancies.[2]

Historically, prenatal care was developed to detect and manage preeclampsia and prevent eclampsia.[3] Much of the current content of care was suggested in a report by the United States Children's Bureau in 1925.[4] Although prenatal care was started as an attempt to control neonatal and maternal morbidity and mortality related to preeclampsia, the goals today have been expanded to foster the well-being of the woman and her fetus in order to ensure healthy outcomes for both. Unfortunately, these are somewhat nebulous goals that prenatal care has never been shown to achieve in a cost-effective way. In fact, there have never been well-designed studies that show that prenatal care improves pregnancy outcomes for large populations. At the same time, the medicalization of prenatal care that results from more interventions such as ultrasound, amniocentesis, and tocolytics has engendered among the public a notion that a perfect outcome for all pregnancies can be guaranteed. Another common notion is that with the advent of better neonatal care, even preterm birth is not a serious problem.

At the same time, financial pressures on providers have forced them to see more and more patients, resulting in visits that are ever more brief. Follow-up prenatal appointments have become little more than a blood pressure check, the measurement of a fundal height, and auscultation of the fetal heart (and, in some offices, an ultrasound examination). This divergence of the public's expectations, the time providers have to devote to their patients' prenatal care, and the lack of proven benefit of prenatal care have contributed in large part to the medical malpractice crisis.

What is needed is a reevaluation of prenatal care, how it is provided, what it can be expected to achieve, and which aspects of it are cost-effective. A first attempt at this was made by the U.S Public Health Service Expert Panel on the Content of Prenatal Care in its 1989 report, Caring for Our Future: The Content of Prenatal Care.[5] More efforts need to be made along these lines. This report took the modest step of suggesting a modified prenatal visit schedule that was subsequently studied by McDuffie and colleagues,[6] who found that in their population, the schedule did not affect pregnancy outcomes. We should begin our reevaluation by examining our successes, such as the detection and management of preeclampsia, the reduction of maternal morbidity and mortality during labor, and the detection of chromosomal aneuploidy and many serious birth defects. We have had success managing many maternal medical conditions during pregnancy, such as pregestational diabetes mellitus and HIV infection.

At the same time, we need to not fall into the trap of using or overusing unproven tools in clinical practice, such as repeated courses of corticosteroids for fetal lung maturity, oral tocolytics, ultrasound, cerclages, or cervicovaginal fetal fibronectin testing.

Bold steps need to be taken and studied for their effectiveness. For example, the U.S Public Health Service Expert Panel on the Content of Prenatal Care suggested that the most important prenatal visit was the one that occurred before conception. By the time a pregnant woman enrolls in prenatal care, the ultimate outcome of her pregnancy may be sealed. Preconception interventions such as folate supplementation to avert fetal birth defects and reduction in exposure to toxic substances such as tobacco and alcohol may have more of an impact on her pregnancy outcome than all of the fundal height measurements she could possibly get. Unfortunately, funding for prenatal care is limited to during pregnancy only, arbitrarily isolating it from the overall health of the woman. A woman's prepregnancy health status has more of an impact on her pregnancy outcome than most of what is offered during traditional prenatal care. Additionally, studies of expanded access to healthcare only during pregnancy have not been shown to be effective at reducing poor pregnancy outcome.[7]

Family planning is a key element of prenatal and preconception care. Pregnancy wantedness has been shown in numerous studies to be associated with pregnancy outcome. Women with negative attitudes about their pregnancies may be less likely to take good care of themselves during their pregnancies and more likely to receive inadequate care.[8] Given that approximately half of the pregnancies in the United States are unintended,[9] a great deal of work needs to be done.

In light of the fact that the highly technical prenatal care of the past few decades has contributed to a medical malpractice crisis and a higher rate of cesarean delivery, and has resulted in minimal change in the rates of low birth weight and preterm delivery, a simpler and more widely available system of prenatal care might be more useful. Efforts should be made to emphasize the quality of visits, not their quantity. "Mothers should come away from each visit better prepared for the remainder of the pregnancy," argues Thomas H. Strong, Jr, a maternal-fetal medicine specialist, in his book, Expecting Trouble: The Myth of Prenatal Care in America.[10]

Attention should be focused on exploring very different models of prenatal care, such as the group prenatal care model being promulgated by the Centering Pregnancy and Parenting Association.[11] This program allows providers to see similar numbers of patients in a given period of time but spend more time with them. Programs such as this seem to result in higher patient satisfaction with their care and allow for significantly more patient education to help them to take responsibility for their own and their family's health and to prepare them for the birth of their child.

Only by taking a fresh look at the system of prenatal care that has become so entrenched can we hope to have any further impact on improving the outcome of pregnancy.


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