Including pregnant and breastfeeding women in clinical trials

Pregnant and breastfeeding women have long been systematically excluded from clinical trials. Physiological changes associated with pregnancy and breastfeeding modify pharmacokinetics, pharmacodynamics, and exposure pathways; trial exclusion therefore creates an evidence gap for safe and effective care. Guidelines recently adopted by the European Medicine Agency and the US Food and Drug Administration12 aim to provide a framework to support inclusion.Women are often willing to participate in clinical trials when properly informed. However, pregnant women were included in roughly 1.1% of trials submitted for regulatory approval between 2019 and 2023, and breastfeeding women in just 0.6%, with the rationale for exclusion often undocumented.3Pregnant women are excluded because of perceived risks to the fetus; ethical complexities (weighing benefits to mother against unknown risks to fetus); liability concerns; social expectations that may deny women autonomy to participate; and resource limitations that discourage investment and participation.456 Many trials impose blanket requirements that women of…