Where are the pregnant and breastfeeding women in new pre-exposure prophylaxis trials? The imperative to overcome the evidence gap.

Pregnant and breastfeeding populations are at substantial risk of acquiring HIV in some settings, yet are underrepresented in clinical trials of new pre-exposure prophylaxis (PrEP) agents. Several PrEP formulations are in development (eg, vaginal rings, long-acting injectables, and other modalities). Pregnant and breastfeeding populations are typically excluded from initial clinical trials. We identified 14 PrEP trials of novel agents in non-pregnant or non-breastfeeding populations, and six phase 1-3 trials and open label extensions among pregnant and breastfeeding populations, that are currently ongoing or complete. A framework shift is needed to consider the ethical costs of excluding pregnant and breastfeeding populations at risk for HIV in PrEP clinical trials and promote inclusion to maximise the benefits from PrEP tools in the pipeline. Research on new PrEP agents should include pregnant and breastfeeding populations to avoid delays in reaching those who could benefit from PrEP after efficacy is established.