WASHINGTON — Pregnant and lactating women are often excluded from clinical trials due to concerns about legal liability, but a new report finds limited evidence of such liability — and says the lack of evidence available to pregnant and lactating women and their clinicians with which to make decisions about using a drug or vaccine poses greater potential for harm than including them in research. The report from the National Academies of Sciences, Engineering, and Medicine recommends improving the safe and ethical inclusion of pregnant and lactating women in clinical research. The Food and Drug Administration should develop clearer guidance on including these populations in clinical trials, Congress should create incentives to encourage their inclusion, and the National Institutes of Health should develop a plan to prioritize research with these populations across its institutes and centers. 

Each year, more than 3.5 million women give birth in the U.S., and some experience serious diseases or conditions that are unique to pregnancy — such as gestational diabetes, preeclampsia, and severe nausea. Pregnant and breastfeeding women also experience many of the same conditions that may require treatment as adults who are not pregnant do, such as depression, cancer, lupus, or HIV. Seventy percent of pregnant women take one or more prescription medications during pregnancy, and the same is true for at least half of all lactating women.

Pregnant and lactating women are excluded from most clinical studies, however, leaving a dearth of data about the appropriate dose, efficacy, and safety of most medical interventions for these populations. Pregnant and lactating patients and their clinicians are therefore forced to make decisions regarding drugs and vaccines without the benefit of high-quality evidence of a product’s effects on the health of the patient, their fetus, or their children. This prompts some pregnant and lactating women to forgo necessary treatment, while others decide to use the medical product and face unknown likelihood of harm and uncertain benefits. Improved inclusion of pregnant and lactating women in clinical trials would generate the research and evidence that they and their health care providers need to make well-informed decisions, the report says.

A case law analysis commissioned by the committee that wrote the report found no claims of liability for injuries resulting from pregnant or lactating women participating in clinical trials since 1962, when the FDA began requiring trials to evaluate the safety and efficacy of drugs before they could be marketed. In contrast, the committee’s analysis found many cases involving liability claims from pregnant women who used drugs that were already approved and on the market. The report says this analysis is the first of its kind, but it is not a complete picture of liability given the limited data available.

Clearer guidance from FDA, detailing expected study designs, safeguards, and product-specific monitoring, would equip investigators and research sponsors with crucial information for safely executing these trials and mitigate potential legal liability. The report recommends FDA revise its guidance to state that studies providing explicit support for drug safety, efficacy, and dosage in pregnant and lactating women should be initiated no later than the end of Phase III of a clinical trial. The guidance should be clear that the requirement to include pregnant and lactating women in a trial is dependent upon available clinical and preclinical safety and efficacy data. If a trial sponsor believes there is evidence that raises concerns about potential harm to pregnant and lactating women or their offspring, the sponsor can submit a justification to the FDA for not including them. FDA should also require that diversity action plans include pregnant and lactating women.

“The current reality facing many pregnant and lactating women who are deciding whether to use an approved drug or medical treatment is that they are essentially taking part in a large and uncontrolled safety experiment,” said committee chair Margaret Foster Riley, professor of law and Dorothy Danforth Compton Professor at University of Virginia. “The status quo of not including pregnant and lactating women in research is not an acceptable path forward, and we recommend that regulatory agencies and policymakers work together to incentivize and improve the safe and ethical inclusion of these populations in clinical trials.”

“Women deserve better evidence about the safety and efficacy of drugs during pregnancy or lactation, and I applaud the urgent action called for in this report to make that evidence available,” said Victor J. Dzau, president of the National Academy of Medicine. “The National Academy of Medicine has long championed the ethical imperative for being inclusive in clinical trials and research and the benefits of doing so.”