Recent research suggests that stress, anxiety, and depression during pregnancy may have an impact on how the child develops. In this article, the central literature supporting this hypothesis is reviewed. Next, studies from our laboratory showing that differences in fetal heart rate patterns are associated with women's anxiety and depressive symptomatology are reviewed. The data indicate that we can detect fetal markers associated with alterations in women's mood that also are linked to differences in the neurobiological substrate of the fetus' emerging emotion regulation system. Identifying such fetal characteristics someday may contribute to the early detection and prevention of predispositions to childhood risk for emotional problems and even psychopathology.