2025/10/23 by Eileen F O’Connor McFerran, Sara K Quinney, Sara K. Quinney · 2 citations
Medicine · #Pregnancy and Medication Impact #Sex and Gender in Healthcare #Pharmacological Effects and Toxicity Studies
paper · doi:10.1093/clinchem/hvaf149
More than 3.5 million births occur annually in the United States (1). Many of these pregnancies are affected by acute or chronic medical conditions such as infection, hypertension, diabetes, and obesity, which require therapeutic intervention. Over 90% of pregnant women take at least one medication during pregnancy, and 30% take 5 or more (2). Despite this, women have long been underrepresented in clinical trials and pregnant or lactating women largely excluded, leaving a knowledge gap in appropriate and safe use of medications in pregnancy. This gap is due, in part, to the historical classification of pregnant women as a vulnerable population, requiring additional protections from clinical trials. While pregnancy or lactation may require additional considerations for research, it does not limit decision-making capacity or the ability to obtain informed consent. Pregnant and lactating patients are complex and understudied, resulting in limited data to guide clinical care. The exclusion of pregnant and lactating individuals from clinical drug trials is a side-effect of attempts to protect potential harm to offspring. Partially in response to the thalidomide tragedy, the FDA excluded women of childbearing potential from early drug research in 1977. The NIH Revitalization Act of 1993 mandated inclusion of women in clinical research and the FDA updated their guidelines allowing participation of women of reproductive age in drug studies. However, it was not until 2019 that pregnant women were no longer labeled as a vulnerable population (3). As demonstrated by Bilinski et al. in an April 2025 study, pregnant women continue to be excluded from clinical drug trials (4). The study evaluated randomized controlled drug trials registered in ClinicalTrials.gov between 2008 and 2023 to determine whether pregnant patients were included, excluded, or not mentioned explicitly. Out of 44 160 trials that were included, only 362 (0.8%) included pregnant patients. Pregnant patients were excluded in 75% and not explicitly mentioned in 24% of trials. Notably, 94% of trials that included pregnant patients excluded any nonpregnant participants, indicating that their focus was specific to pregnancy. Trials including pregnant patients were more often open label, focused on prevention, and less likely to be industry sponsored. These trials were predominantly related to labor and delivery, pregnancy-related conditions and preterm labor (4).