Stress and the female reproductive system.

The hypothalamic-pituitary-adrenal (HPA) axis, when activated by stress, exerts an inhibitory effect on the female reproductive system. Corticotropin-releasing hormone (CRH) inhibits hypothalamic gonadotropin-releasing hormone (GnRH) secretion, and glucocorticoids inhibit pituitary luteinizing hormone and ovarian estrogen and progesterone secretion. These effects are responsible for the "hypothalamic" amenorrhea of stress, which is observed in anxiety and depression, malnutrition, eating disorders and chronic excessive exercise, and the hypogonadism of the Cushing syndrome. In addition, corticotropin-releasing hormone and its receptors have been identified in most female reproductive tissues, including the ovary, uterus, and placenta. Furthermore, corticotropin-releasing hormone is secreted in peripheral inflammatory sites where it exerts inflammatory actions. Reproductive corticotropin-releasing hormone is regulating reproductive functions with an inflammatory component, such as ovulation, luteolysis, decidualization, implantation, and early maternal tolerance. Placental CRH participates in the physiology of pregnancy and the onset of labor. Circulating placental CRH is responsible for the physiologic hypercortisolism of the latter half of pregnancy. Postpartum, this hypercortisolism is followed by a transient adrenal suppression, which may explain the blues/depression and increased autoimmune phenomena observed during this period.