New fetal therapies offer important prospects for improving health. However, having to consider both the fetus and the pregnant woman makes the risk–benefit analysis of fetal therapy trials challenging. Regulatory guidance is limited, and proposed ethical frameworks are overly restrictive or permissive. We propose a new ethical framework for fetal therapy research. First, we argue that considering only biomedical benefits fails to capture all relevant interests. Thus, we endorse expanding the considered benefits to include evidence-based psychosocial effects of fetal therapies. (...) Second, we reject the commonly proposed categorical risk and/or benefit thresholds for assessing fetal therapy research. Instead, we propose that the individual risks for the pregnant woman and the fetus should be justified by the benefits for them and the study’s social value. Studies that meet this overall proportionality criterion but have mildly unfavorable risk–benefit ratios for pregnant women and/or fetuses may be acceptable. (shrink)