This book focuses on the production and regulation of steroids, peptides, and other regulatory factors by the placenta and by maternal and fetal organs, especially brain. These regulatory factors play vital roles in the maintenance of pregnancy, the timing and onset of labor, fetal growth and development, especially the programming of fetal physiology, and maternal and fetal neural function and regulation. The maternal–placental–fetal axis is an important target for research into the regulation and control of human pregnancy. A subtext of the book is the role of maternal–placental–fetal interactions in the onset of disease and disability, especially from preterm birth and fetal programming of physiologic systems that lead to adult onset diseases, such as diabetes and hypertension. The book addresses the relationships among glucocorticoids, neuropeptides (primarily corticotropinreleasing hormone,(CRH), maternal nutrition, psychosocial ‘stress’, fetal growth and development, the onset of labor, and subsequent effects on health and behavior of infants, children and adults (Figure I.1).