In 16 normal and pathologic pregnancies we carried out the dehydroepiandrosterone-sulphate loading test by injection of 50 mg DHEA-S-Na intravenously. The plasma concentrations of unconjugated estradiol and estriol were measured by radioimmun-assay. The level of estradiol increased continuously, rising to a maximum 60 min after the injection. In pre-eclamptic patients and cases of intrauterine growth retardation the rise was significantly reduced. There was a good correlation between result of the test and clinical dates. In plasma concentrations of unconjugated estriol no changes could be observed within 3 hours after the injection.