In 1993, the lead author of the MRC study, Dr. Nicholas Wald, wrote the following:
The critical timing of folic acid supplementation is not known but it is likely to be immediately before and during embryonic neural tube defect closure, that is, by four weeks from the date of conception or about six weeks from the first day of a pregnant woman’s last menstrual period. There is necessarily uncertainty over when a woman will become pregnant, and she may seek medical attention only some weeks after her first missed menstrual period, which would be too late for folic acid supplementation to be effective. The general advice to women, therefore, must be to take folic acid supplementation from the time they decide to try to become pregnant. Failing that, the use of supplements immediately after a woman suspects she is pregnant is likely to confer a benefit in a proportion of cases, but to what extent is unknown.112
Wald’s quote made clear that, even though the timing of the effect was inconclusive, the period around conception was deemed newly important. After a heated scientific debate over the timing effect and the safe amount of dosage, the U.S. Food and Drug Administration (FDA) issued a final rule in 1996 to fortify the nation’s grain and cereal supply with folic acid.113 Compliance with this rule became mandatory in 1998.114 One government administration official remarked that the FDA rule would presume “all women are pregnant unless proven otherwise.”115 Pregnancy no longer presented the burden of proof for women to face recommendations for a healthy pregnancy, and thus prenatal care represented an intervention too late for preventing one of the most common congenital birth defects. The zero trimester was beginning to take shape.
Notably, the research attention to folic acid emerged alongside greater attention to the role of embryonic and fetal development in the medical literature. Obstetric ultrasound had become a common method for seeing the fetus.116 Medical innovation and technology thus made it easier to regard the fetus as a patient and focus more than ever on fetal health and well-being, but there was also rising visibility of the embryo soon after conception.117 By the 1980s, studies expanded previous research from the earlier part of the century118 to show that the nervous system in human embryos is in formation by approximately twenty days post-ovulation.119 This science matters for the present discussion because the 1980s witnessed a growing research agenda on pre-pregnancy interventions—such as folic acid—that might positively impact very early embryonic development and thus offset the risk of birth defects.
Moreover, the research on folic acid supplementation and NTDs coincided with the emergence in the 1980s of the “fetal origins hypothesis,” also known as the “Barker hypothesis.” The fetal origins hypothesis, as presented by Dr. David J. P. Barker, postulated that there are long-term effects of fetal exposures, effects that might not become visible until much later in life.120 Indeed, immediate effects of fetal exposures—and realization that the placenta was permeable—were already apparent through birth defect disasters such as that experienced with the drug thalidomide and with the German measles epidemic of the mid-twentieth century.121 The Barker hypothesis, though, renewed concerns about life-course health as setting the stage for healthy reproduction and also bolstered an epigenetic idea; that is, Barker’s notion suggested that some underlying mechanism “programs” risk susceptibility, in which portions of the epigenome are switched on or off during the fetal period.122
The foundation for a renewed medical focus on early embryonic development—and on interventions that would enhance the environment of that development—set the context for the renewed rise of “pre-pregnancy” thinking in the world of obstetrics and maternal and child health in the late twentieth century. Reproductive medicine had a new golden tool for reducing risk.
EXPANDING AND DEBATING REPRODUCTIVE SURVEILLANCE
As mentioned throughout this chapter, many contemporary maternal and child health professionals assert that pre-pregnancy care began in 1980 with an article on “prepregnancy clinics” in the British Medical Journal by Geoffrey Chamberlain. Chamberlain’s clinic initially was set up in 1978 as a place for women to learn about risks to their health and the health of their future baby. The clinic identified maternal risks (e.g., previous pregnancy complications or current conditions, such as epilepsy) and fetal risks (e.g., previous multiple births or recurrent abortions). Chamberlain argued that an obstetrician should run a pre-pregnancy clinic.123 Letters in response to Chamberlain’s article questioned the novelty of his pre-pregnancy clinic idea: such a clinic had been set up in Australia in 1979124; women in a London practice had reportedly requested pre-pregnancy “check-ups” since 1969.125
Soon after, in 1981, the British Medical Journal ran an editorial on “preconception clinics.” It argued that the question concerning whether obstetric care should begin before conception should be given “careful consideration,” despite the fact that some physicians deem this only a “philosophical” question.126 It would be a chance for obstetricians to counsel women with chronic conditions, the editorial argued. This piece also cited the recent “suggestions” by Smithells and colleagues in the Lancet about early evidence regarding folic acid and neural tube defects. The BMJ editorial evinced temporal reasoning in promoting pre-conception care as a new extension of the management of pre-pregnant women: “At present women usually present to the obstetrician for the first time with symptoms suggesting the fetus is already jeopardized. . . .”127 Physicians during this time might have been dismayed at their lack of control over the early prenatal period, when embryos are growing rapidly, when women are not yet seeking care, and when the fetus is “already jeopardized.” Some letters in response to this editorial jumped on the bandwagon, adding occupational hazards and alcohol as potential exposures women should avoid in the pre-conception period to avoid harm to future embryos.128 One physician argued that a pre-pregnancy clinic would be a great place to warn women about alcohol reduction and the impact on pregnancy, buttressing his contention with the mention that Americans and their surgeon general have already included “all women who are contemplating pregnancy” to stop drinking.129 Another physician argued that a pre-conception visit would “improve the obstetrician’s ability to manage the pregnancy.”130
It is clear from this discussion in the medical literature that pre-pregnancy care could increase the surveillance capacity of obstetricians over their patients. These early obstetrical proponents argued that there are specific embryological risks which might not be well understood but for which there is a need for physician oversight. The BMJ editorial, for instance, made a bold claim—one that would continue throughout subsequent medical literature on pre-pregnancy health: that potential damage to the fetus is done during the time when the pregnancy is unsupervised. If risks of adverse outcomes are in place during this early embryonic period, a discussion about the necessity of prenatal care was obviated to some commentators at the time. Prenatal care would continue to serve as treatment, not prevention.
By 1982, there was growing interest in health care around the time of conception and its impact on the reduction of birth defects and infant well-being.131 One study found that a clinic helped management of diabetes in pregnant women “particularly at the time of conception and throughout the first trimester.”132