Gender equality in clinical trials continues to be a hot topic in the EU. The Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) began producing gender focused clinical trial guidelines in the 1990s, since which time regulators have continued their efforts to improve the representation of women in clinical trials. Pregnant and lactating women, however, still fall behind. Currently less than 0.4% of all clinical trials submitted in the EU include pregnant people, and 0.1% include lactating women.

To improve this, in 2025, the EMA, together with other regulators through the ICH, released a new draft guideline providing recommendations for the appropriate inclusion and/or retention of pregnant and/or lactating women in clinical trials, and to facilitate the generation of robust clinical data that allow for evidence-based decision making on the safe and effective use of medicinal products by these women and their health care providers.

Currently, under the applicable Regulation (EU) No 536/2014 (the "Clinical Trial Regulation" (CTR)), it is required that, unless otherwise justified, trial subjects must be representative of the target population for the applicable medicinal product; however, there are no binding metrics in the EU for the inclusion of women, or subsets of women, in clinical trials. The CTR contains several safeguards when including pregnant and lactating women in clinical trials, including that the clinical trial has the potential to produce a direct benefit for the pregnant or lactating woman concerned, or her embryo, fetus, or child after birth, outweighing the risks and burdens involved.

The draft guideline provides further guidance in this regard and mentions that the inclusion of pregnant and lactating women in clinical trials should be considered for all medicinal products where individuals of childbearing potential are among the anticipated user population, especially for conditions where there is high unmet medical need for treatment in pregnancy or while breastfeeding. This may provide a new perspective compared to the prior tendency to exclude pregnant and lactating women from clinical trials and to discontinue those who become pregnant while participating in a clinical trial, although the benefit-risk assessment remains paramount.

The final version of the guideline is yet to be published and is expected to be implemented in the local regional regulatory systems in Q1 2028. Once adopted, it may impact the setup of clinical trials and the inclusion of clinical trials subjects, as well as postmarketing clinical trials for indications in the general population or for indications specific to pregnant or lactating women.