Peripartum concentrations of beta endorphin and cortisol and maternal mood states.

Nineteen women were studied before, during and after labour by assessment of their mood using a variety of psychological tests and by measurement of their plasma concentrations of beta-endorphin and cortisol. Beta-endorphin and cortisol concentrations rose markedly during labour and were influenced by the type of analgesia used. A deterioration in cognitive performance between days 2 and 4 postpartum correlated positively with the fall in beta-endorphin concentrations from those in labour to those on the fourth day postpartum. The women were more anxious and depressed at 38 weeks' gestation than on days 1-4 postpartum and the elevation of mood on day 2 postpartum correlated with a measure of depression 8 weeks later. It is postulated that the phenomenon of postpartum blues is a reaction to the euphoria of delivery which in turn is a response to endorphin release during labour. Whilst these changes may have a role in promoting maternal-infant attachment it is at the expense of maternal depression some weeks later.