The cause of many of the adverse reproductive outcomes and developmental diseases among offspring is not well understood. Most of the epidemiologic and experimental animal research has focused on the relationship between maternal exposures including medications, tobacco smoke, alcohol, infections, and occupation and the occurrence of spontaneous abortion, low birth weight, and birth defects. The potential role of paternal exposures has not been investigated as extensively despite long-standing animal research that demonstrates the induction of mutations in the male germ cell after exposure to...