HIGH PROGESTERONE IS RELATED TO EFFECTIVE HUMAN LABOR - STUDY OF SERUM PROGESTERONE AND 5-ALPHA-PREGNANE-3,20-DIONE IN NORMAL AND ABNORMAL DELIVERIES

Background The role of progesterone levels during human labor is uncle ar. Objective. To investigate serum concentrations of progesterone and 5 alpha-pregnane-3,20-dione in normal and abnormal deliveries. Method 's. Venous and umbilical cord serum samples were collected from 108 pa rturient women. In a further 49 deliveries, arterial and venous umbili cal cord sera were collected separately. The concentrations of progest erone and 5 alpha-pregnane-3,20-dione were determined by radioimmunoas say. The delivery modes studied were: elective cesarean section; oxyto cin-resistant dystocia; normal but induced delivery, and normal sponta neous delivery. Results, Progesterone concentrations in maternal and u mbilical serum were higher following normal labor than after dystocia (p<0.005) and elective cesarean section (p<0.005), The maternal and um bilical progesterone concentrations in dystocia and elective cesarean section were between 77-43 % of those in normal labor, The concentrati ons did not vary between gestational weeks 37 and 42, within the diffe rent modes of delivery. The 5 alpha-pregnane-3,20-dione serum concentr ation in the fetal compartment was twice that in the maternal compartm ent (p<0.001); its concentration in venous umbilical serum was higher than in corresponding arterial samples (p<0.001). No distinct differen ces in the 5 alpha-pregnane-3,20-dione serum concentration were found with regard to parity or mode of delivery. Conclusion. High progestero ne concentrations during parturition appear to be related to effective labor. The findings support results from in vitro experiments on huma n term myometrium.