Leading gender and science scholar Sarah S. Richardson charts the untold history of the idea that a woman’s health and behavior during pregnancy can have long-term effects on her descendants’ health and welfare. The idea that a woman may leave a biological trace on her gestating offspring has long been a commonplace folk intuition and a matter of scientific intrigue, but the form of that idea—and its staggering implications for maternal well-being and reproductive autonomy—has changed dramatically over time. Beginning with the advent of modern genetics at the turn of the twentieth century, biomedical scientists dismissed any notion that a mother—except in cases of extreme deprivation or injury—could alter her offspring’s traits. Consensus asserted that a child’s fate was set by a combination of its genes and post-birth upbringing.   Over the last fifty years, however, this consensus was dismantled, and today, research on the intrauterine environment and its effects on the fetus is emerging as a robust program of study in medicine, public health, psychology, evolutionary biology, and genomics. Collectively, these sciences argue that a woman’s experiences, behaviors, and physiology can have life-altering effects on offspring development. Tracing a genealogy of ideas about heredity and maternal-fetal effects, The Maternal Imprint offers a critical analysis of conceptual and ethical issues provoked by the striking rise of epigenetics and fetal origins science in postgenomic biology today.