Effects . of hydralazine . on placental . and renal circulation in pre-eclampsia

Background. Although hydralazine has been the drug of choice for treating pregnancy-induced hypertension for some time owing to its effect on peripheral vascular tonus, its effects on utero- and feto-placental circulation are less well understood.Methods. To evaluate the effect of hydralazine on placental circulation in cases of pre-eclampsia, Doppler ultrasonography was used to record blood velocity in the arcuate and umbilical arteries in 12 pregnancies complicated by pre-eclampsia, blood velocity in the maternal renal artery also being examined. The gravidae underwent Doppler ultrasonography after 24 hours bedrest in hospital (baseline values), and again 24 and 72 hours after starting oral hydralazine treatment at doses of 50 mg twice daily.Results. The gravidae showed increased heart rate and decreased blood pressure in response to treatment, but neither placental nor maternal renal blood velocity waveforms were affected.Conclusion. The results suggest that at recommended oral doses hydralazine has no...