Effect of stress during labor on the concentration of cortisol and estriol in maternal plasma.

The effect of stress during labor on the plasma concentration of cortisol, unconjugated estriol, and human chorionic somatomammotropin was studied in 15 healthy primiparous women. According to the method of pain relief the parturients were divided into two groups. One group was given continuous epidural analgesia and the other group received pethidine, diazepam, and nitrous oxide/oxygen in response to pain. In the most stressed nonepidural group there was a significant rise in the cortisol level during labor and the estriol concentration fell significantly. In the epidural group no significant changes were observed with respect to the concentration of either cortisol or estriol. These results give further support to the hypothesis that severe maternal stress may lead to a reduced concentration of estriol in maternal plasma.