To study the changes in fetal hemodynamics with intravenous labetalol or nifedipine in acute severe hypertension

Abstract

Objective: To compare the efficacy of intravenous labetalol or oral nifedipine in treatment of acute maternal hypertension and study the fetal hemodynamic changes using color Doppler ultrasound that follows treatment.

Study design: Thirty women with severe preeclampsia having acute hypertension (more than or equal to 160/105 mmHg) were randomized in 2 groups to receive intravenous labetalol or oral nifedipine until blood pressure was lowered to less than or equal to 140/90 mmHg. Doppler vascular indices namely pulsatility index, resistance index, S/D ratio of umbilical (UA) and middle cerebral artery (MCA) were measured baseline at the time of acute severe hypertension and repeated after control of blood pressure, to assess the changes in fetal hemodynamics if any with labetalol or nifedipine.

Results: Both nifedipine and labetalol were found to be effective when used for rapid control of blood pressure. Mean age of women in both groups and mean gestational age was statistically comparable. No change in fetal heart rate before and after treatment was observed in both groups. Doppler vascular indices of UA and MCA showed no significant changes as compared to baseline values in both groups.

Conclusion: The use of labetalol and nifedipine were not related to any significant changes in fetal Doppler, which is reassuring about the safety of these drugs when treating acute severe hypertension in pregnancy. Choice between these two drugs should be based on cost, availability respective contraindications, and clinician's experience.

Keywords: Doppler; Hypertension; Labetalol; Nifedipine; Pregnancy.