Prostaglandins in the human umbilical circulation at birth.

Prostaglandin E (PGE), prostaglandin F (PGF) and 13, 14-dihydro-15-keto-prostaglandin F (PGFM) have been measured in umbilical cord plasma obtained immediately after delivery of the baby before clampiing of the cord. In general the prostaglandin levels followed the pattern PGFM greater than PGE greater than PGF. A significant arterio-venous difference was demonstrated only for PGE with raised venous levels (P less than 0.01). In cord blood samples obtained from infants whose mothers had received epidural anaesthesia, no arterio-venous difference for PGE could be demonstrated although the mean levels were not significantly different from controls. The concentrations of prostaglandins in umbilical cord plasma proximal to the placenta were found to rise continuously from the time of delivery of the baby with no significant changes after cord clamping or placental delivery. The possible physiological significance of these findings is discussed.