Despite shaky evidence, American medical literature in the twenty-first century includes assumptions about the ability of expectant women's psyche to impact their pregnancy. This essay argues that such notions are rooted in "prenatal psychology," a discursive hybrid constructed by renowned psychiatrists in the 1940s and 1950s. Benefiting from the popularity of Freudianism and from women's social status after the war, doctors like Karl Menninger, William Menninger, Helene Deutsch, and Flanders Dunbar fused traditional ideas about the power of women's emotions to influence pregnancy with trendy ego psychology and psychosomatic theories. They argued that women who experienced difficult pregnancies, threw up excessively or miscarried, suffered from a problem that had a name: neurosis. Several leading obstetricians and gynecologists embraced these ideas and helped spread them in the professional literature, urging their colleagues to use talk therapy in the care of pregnant women.