Effect of Local Prostaglandin E₂ on Uterine and Fetal Doppler Flow in Pregnancy-Induced Hypertension

Abstract

Objectives: To evaluate the effects of vaginal and intracervical administration of prostaglandin E₂ (PGE₂) on the uterine, umbilical, and fetal blood flow in hypertensive pregnancies.

Methods: Thirty-two women with pregnancy-induced hypertension undergoing cervical ripening for preinduction of labor were randomized to receive either 2.0 mg of PGE₂ gel vaginally (n = 12), 0.5 mg of PGE₂ gel intracervically (n = 10), or placebo gel vaginally (n = 10). The pulsatility index (PI) and resistance index (RI) in uterine arteries, umbilical artery, and fetal middle cerebral artery were calculated before and 30 and 60 min after administration of PGE₂ or placebo.

Results: Placebo gel caused no changes in any one flow variable. Because the vaginal and intracervical mode of administration of PGE₂ caused similar changes in flow, these groups were combined. PGE₂ increased (P < 0.0001) impedance to flow in uterine arteries 30 min (9.7 ± 2.8%, mean ± SE) and 60 min (20.5 ± 4.8%) after application. In contrast, impedance to flow tended to decrease in fetal cerebral arteries 30 min (8.1 ± 4.0%, NS) and 60 min (11.5 ± 3.5%, P < 0.004) later. No changes were seen, following PGE₂ use, in umbilical blood flow. No clear-cut relationships could be found between changes in blood flow and uterine contractility, as assessed by external tochography.

Conclusion: In hypertensive pregnancies, cervical ripening with PGE₂ gel leads to increase in uterine vascular resistance, and to decrease in fetal middle cerebral artery resistance.

Key Words:

• Doppler
• Pregnancy-induced hypertension
• Prostaglandin E₂