Management of severe preeclampsia detected in early labor by prostaglandin A1 or dihydralazine infusions.

The presence of severe pregnancy-induced hypertension at the onset of labor requires therapy with a potent hypotensive agent. Prostaglandin A1 is a powerful vasodepressor that augments renal blood flow and glomerular filtration and possesses antiplatelet aggregator and oxytocic properties. A continuous intravenous infusion of prostaglandin A1 (40 to 50 micrograms/min) or dihydralazine (35 to 50 micrograms/min) was administered to 20 women with severe preeclampsia (10 in each group). The induced hypotensive response was similar with both drugs but the maximum reduction in blood pressure was achieved sooner with dihydralazine (4 hours) compared with prostaglandin A1 (7.5 hours). The more gradual hypotensive response is probably less dangerous on placental perfusion than a sudden change. Moreover, the oxytocic property of prostaglandin A1 shortened the time to delivery, which constitutes another potential advantage.