Loss of circadian rhythms of fetal behaviour in a totally adrenalectomized pregnant woman.

Fetal heart rate and fetal movements were recorded over a 24-hour interval in a totally adrenalectomized pregnant woman at term. Cortisol, ACTH, unconjugated estriol and 17 beta-estradiol were contemporaneously measured every 2 h in the maternal peripheral plasma. Owing to the substitution therapy the patient showed a loss of circadian variations of all the hormones investigated. Moreover, the circadian rhythms of fetal heart rate and fetal movements, usually present at term, were no longer evident. We can thus suggest that the circadian variations of plasma maternal cortisol could affect the alternations of fetal behaviour.