The short-term effect of 0.8 mg/kg of an intravenous bolus of labetalol on maternal and fetal hemodynamics was investigated in ten women with pregnancy-induced hypertension. The maximum effect occurred within 35 minutes after labetalol administration. At that point, the mean arterial pressure had decreased by 18% and there was a slight decrease in maternal heart rate. As to flow velocity waveforms, no significant change was found in mean systolic/diastolic (S/D) ratio of the uterine artery, umbilical artery or fetal middle cerebral artery. However, in two subjects with a marked reduction in blood pressure also the uterine artery S/D ratio decreased.