Effects of methyldopa on umbilical and placental artery blood flow velocity waveforms.

Abstract

To identify the effects of methyldopa on umbilical and placental artery Doppler velocity waveforms in mild preeclamptic and chronic hypertensive women with blood pressure below 160/110 mmHg. Twenty-two normotensive, 11 untreated mild preeclamptic, 14 treated mild preeclamptic, 29 untreated chronic hypertensive, and 14 treated chronic hypertensive women were studied. Methyldopa was begun if the blood pressure remained higher than 140/90 mmHg after 24 hours of hospitalization. The pulsatility index (PI) was measured on days 0 and 7. Blood pressure decreased significantly with methyldopa in chronic hypertensive women only (P < .05). The PI did not vary in the umbilical artery in the five groups, or in the placental artery in normotensive, untreated preeclamptic, and untreated chronic hypertensive women. The PI decreased significantly in treated preeclamptic and chronic hypertensive women (P < .05). Birth weight was similar in the hypertensive groups. Methyldopa decreases placental vascular resistance in mild preeclamptic and chronic hypertensive women.