HIV/AIDS is among the most serious diseases confronting women who are pregnant. It is also one of the few areas of research involving humans where there is a long track record of research involving pregnant women. Yet the HIV/AIDS research community has struggled to expand the research agenda from research to prevent mother-to-child transmission of HIV to research encompassing issues pertaining to the pregnant woman’s own health. Research questions of interest include: which antiretrovirals are safest and most effective for pregnant women; how best to pursue preventive regimes for pregnant women who are not infected; or, how to treat HIV’s deadly co-infections, such as tuberculosis (TB), during pregnancy. In this chapter, we describe two key lessons about research in pregnancy from the context of HIV/AIDS: first, why addressing the health needs of pregnant women, not just the needs of their offspring, is so critical; and second, why doing so is immediately possible, even as we work to resolve certain ethical and regulatory debates, particularly about when it is appropriate to impose foetal risk without the prospect of foetal benefit. In particular, the HIV/AIDS context shows how treatment or prevention of maternal disease often entails not just risk – but the prospect of benefit – to the foetus; and creative trial designs can advance no-benefit studies without imposing foetal risk in the first place. For all the challenges that research with pregnant women entails, the HIV/AIDS context reveals that it is possible to conduct a wide range of important research during pregnancy that is both ethically responsible and consonant with US regulations.