A RECENT study explored the inclusion of pregnant participants in randomised clinical trials (RCTs) over a 15-year period. The analysis aimed to understand the extent of their representation, the focus of trials involving pregnancy, and funding disparities. Despite increasing calls for greater inclusion of pregnant individuals in clinical research, the study revealed that their participation remains limited and stagnant.
The researchers reviewed over 90,000 RCTs conducted between 2008 and 2023. Of these, only 0.8% included pregnant participants. In contrast, 75% explicitly excluded them, and 24% did not specify their inclusion. These proportions remained consistent throughout the study period. Trials that did include pregnant participants predominantly focused on pregnancy-specific issues, such as preterm labour, labour and delivery, and infection prevention. However, only 5% of these trials addressed chronic non-infectious conditions like asthma or diabetes, which are increasingly prevalent during pregnancy.
The study also identified differences in trial characteristics. RCTs involving pregnant individuals were more likely to be open-label and focused on prevention, such as reducing risks of preterm labour or mother-to-child transmission of infections. In contrast, trials excluding or failing to specify pregnant inclusion were more often treatment-focused. Funding patterns revealed disparities, with RCTs enrolling pregnant participants less likely to receive industry funding.
Manual reviews of trials that did not specify pregnancy inclusion criteria found no evidence that pregnant individuals participated. In many cases, further analysis confirmed their exclusion. Meanwhile, conditions unrelated to pregnancy, such as infertility or erectile dysfunction, received significantly more research attention, highlighting a disparity in priorities.
The study emphasises the urgent need for increased inclusion of pregnant individuals in clinical research. The lack of pregnancy-specific RCTs creates significant gaps in evidence, limiting healthcare providers’ ability to deliver safe and effective care. Addressing this issue requires targeted funding, policy changes, and a commitment to expanding research efforts to improve maternal and foetal health outcomes.
Katie Wright, EMJ
Reference
Bilinski A, Emanuel N. Fewer than 1% of US Clinical Drug Trials Enroll Pregnant Participants. Am J Obstet Gynecol. 2025;DOI:10.1016/j.ajog.2024.12.028.
