PLASMA PROLACTIN CONCENTRATIONS AFTER CESAREAN-SECTION OR VAGINAL DELIVERY

The umbilical venous plasma prolactin concentrations of three groups o f term infants were compared immediately after birth. Samples were tak en following seven vaginal deliveries, eight emergency caesarean secti ons performed during labour, and 12 elective caesarean sections before labour. Mean concentrations of prolactin were significantly lower in the elective caesarean section group compared with the labour groups. This result indicates that the fetal hypothalamic-pituitary axis is st imulated during labour which could explain the increase in plasma prol actin concentrations at birth.