Isradipine, a new calcium antagonist: effects on maternal and fetal hemodynamics.

To assess the effect of isradipine on blood pressure, and uteroplacental and fetal blood flows in pregnancy-induced hypertension, 41 women with a diastolic blood pressure greater than or equal to 95 mm Hg were included in our study. Of these, 27 received isradipine 5 mg twice daily. Uteroplacental blood flow index was calculated from the activity-time curve of the very low radiation from the placenta after intravenous injection of 18.5 MBq indium-113m. Blood flow velocity was measured in the uterine and umbilical arteries, and fetal aorta, using the pulsed Doppler technique. Investigations were performed before and after 1 week of isradipine. A control group of 14 women was examined in the same way. The isradipine group showed a significant reduction in mean arterial pressure (from 117 to 112 mm Hg) whereas there was no change in the controls. Uteroplacental blood flow indices were similar before treatment in both groups and did not change during treatment. Furthermore, the pulsatility indices were the same in both groups at the first examination and also did not change. Isradipine had no adverse effects on the fetus. In conclusion, isradipine lowered blood pressure without altering uteroplacental or fetal blood flows.