116 women with obstetric hepatosis gave birth in the years 1971-1972 at the First and Second Departments of Obstetrics and Gynaecology, University Central Hospital, Helsinki. This accounts for a 1.1% incidence of all deliveries at this hospital. During most of these pregnancies fetal well-being was monitored by amnioscopy, by the oxytocin challenge test, by maternal urinary oestriol determinations and by estimating the fetal biparietal diameter weekly. In 38% of these pregnancies, signs of fetal distress were found, mainly an abnormal heart rate, or heart rate pattern, and/or meconium-stained amniotic fluid. These led to increased frequencies of induction of labour and of Caesarean sections performed because of asphyxia or imminent asphyxia as compared with a control group with similar age and parity distribution. There was an increase in the occurrence of twin pregnancies in the hepatosis series (7.6%). There were 4 intrauterine and altogether 8 perinatal losses of 125 infants born to hepatosis mothers. These observations suppport the opinion that there are increased risks for the fetus in pregnancies complicated by obstetric hepatosis. Amnioscopy and fetal heart rate recording during the delivery and oxytocin challenge test were found to be valuable in monitoring the fetal condition. The use of oestriol determinations, at least by employing the method in general clinical practice, was found to be of limited value in the predictive assessment of fetal distress in hepatosis. This might be due to impurities disturbing the determinations or to changed oestrogen metabolism in cholestasis.