In contrast to many areas of health research, the field of HIV/AIDS has pursued research with pregnant women as a key component of its research agenda. Several large trials have made vivid a number of critical ethical questions for research with pregnant women broadly–including how risks and benefits can and should be traded off between the woman, the fetus, and the future child–offering an important opportunity for building an adequate ethical framework for research in pregnancy, more generally. As a part of a multidisciplinary research project addressing barriers and opportunities to conducting research with pregnant women (the PHASES project–Pregnancy and HIV/AIDS: Seeking Equitable Study), we examined several large HIV network studies conducted in the last five years that required risk/benefit tradeoffs between woman, fetus and future child in conjunction with U.S. research regulations and the research ethics literature. Selected studies were analyzed in conjunction with U.S. research regulations and the research ethics literature. We describe three challenging tradeoff scenarios encountered in HIV network studies and develop an approach that is consistent with US regulations governing research with pregnant women. The inclusion of pregnant women in clinical research can be justified based on 1) the prospect of direct and indirect benefit to fetus; 2) the imposition of no more than minimal risk for studies involving no prospect of benefit to fetus; or 3) a reasonable ratio of maternal benefit to fetal risk. Tradeoffs between the fetus and the future child risk should be responsive to potential participants’ values.