Since the late 1980s, the fetal origins of adult disease, from 2003 developmental origins of health and disease (DOHaD), has stimulated significant interest in and an efflorescence of research on the long-term effects of the intrauterine environment. From the start, this field has been interdisciplinary, using experimental animal, clinical and epidemiological tools. As the influence of DOHaD on public health and policy expanded, it has drawn criticism for reducing the complex social and physical world of early life to women’s reproductive (...) bodies as drivers of intergenerational ills. This paper explains this narrowing of focus in terms of a formative and consequential exchange between David Barker, the British epidemiologist whose work is credited with establishing the field, and the discipline of fetal physiology. We suggest that fetal physiologists were a crucial constituency of support for Barker’s hypothesis about early life origins of disease. Their collaborations with Barker helped secure and sustain the theory amid considerable controversy. The trajectory of DOHaD and its focus on the maternal body can be understood, we argue, as a consequence of this alliance, which brought together two distinct conceptualizations of the intrauterine environment, one from epidemiology and the other from fetal physiology. Along the way, we trace the histories of these conceptualizations, both of which were products of mid-to-late twentieth century British science, and show how Barker’s early emphasis on social and economic conditions was superseded by a narrower focus on physiological mechanisms acting upon the autonomous fetus. (shrink)