Dehydroepiandrosterone sulfate loading test in the diagnosis of complicated pregnancies

To assess placental and fetoplacental function, 50 mg of dehydroepiandrosterone sulfate was administered intravenously to 11 normal obstetric patients at 35 to 40 weeks and to 36 high-risk patients at 35 to 43 weeks of pregnancy. Plasma estradiol converted from dehydroepiandrosterone sulfate by the placenta increased in all patients after infusion, with maximal concentrations of 28 to 65 ng per milliliter 30 to 60 minutes after infusion (P less than 0.01). Plasma estetrol, produced by the fetus from estradiol, increased in all patients with maximal concentrations of 0.8 to 3.2 ng per milliliter four hours after infusion (P less than 0.01). In complicated pregnancies a subnormal rise of estradiol and estetrol was highly suggestive of fetal distress whereas a normal rise was associated with no fetal distress. The simultaneous determination of estradiol and estetrol after dehydroepiandrosterone sulfate infusion may reflect placental and fetoplacental function, and may be used as an adjunct to other methods of assessing fetal well-being.