Antihypertensive drug effects on placental flow velocity waveforms in pregnant women with severe hypertension.

Doppler studies of the uterine and umbilical arteries were performed in 24 acutely hypertensive pregnant women. Women were divided into 2 groups: Group 1 (diastolic blood pressure (DBP) > 110 mm Hg) received placebo (n = 6) or 10 mg oral nifedipine (n = 9); Group 2 (DBP > or = 110 mm Hg) received 10 mg oral nifedipine (n = 5) or 10 mg intravenous hydralazine (n = 4). Treatment allocations were random within groups and the investigator and patient were blind to the treatments. Baseline flow velocity waveforms (FVW) and posttreatment FVW's at 30, 60 and 120 minutes were recorded. There was no significant difference between baseline and posttreatment FVW indices within or between groups. Placebo was as effective as nifedipine in lowering blood pressure over 2 hours of study. There were no significant adverse effects of treatment.