Immunoreactive Beta-Endorphin in Maternal and Umbilical

Abstract

Immunoreactive (3 -endorphin was measured in the umbilical arterial and venous plasma of 55 neonates, in venous plasma of 24 women immediately after vaginal delivery and 16 normal nonpregnant women. After birth, (3 -endorphin concentrations in maternal and umbilical cord plasma were significantly higher than those in normal nonpregnant women. There was no arterio-venous difference in the umbilical cord plasma. Umbilical arterial plasma (3 -endorphin level was not affected by the mode or route of delivery but umbilical venous plasma (3 -endorphin level was significantly higher after spontaneous vaginal delivery than at elective cesarean section. Umbilical cord plasma (3 -endorphin level was significantly elevated in conjunction with fetal distress. No significant correlation was found between maternal and umbilical cord plasma (3 -endorphin levels.