Objective: Review of the physiological role of neuroactive and neuroprotective steroids in human pregnancy.
Design: A review article.
Setting: Gynecological-Obstetrical Clinic, 1st Medical Faculty, Charles University and General Hospital, Prague.
Conclusion: Human parturition is a multi-factorial process. Various mechanisms related to the onset of labor were suggested. Estrogens show accelerating increase in late pregnancy, which probably reflect the increasing activity of fetal zone of the fetal adrenal. This zone is stimulated by progressive increase of placental CRH resulting in excessive production of conjugated 3beta-hydroxy-5-en-steroids, which are transported by circulation to placenta and further metabolized to active hormones. Some progesterone metabolites probably participate in pregnancy sustaining via modulation of ligand-gated ion channels in the CNS and periphery. In this review, the question was addressed whether the catabolism of pregnancy sustaining progesterone metabolites accelerate like the estrogen formation.