A dose-finding study of oral misoprostol for labor augmentation.

Abstract

We designed a dose-finding trial of oral misoprostol administered for labor augmentation. Healthy, nulliparous women in active labor and diagnosed with arrest of dilation were enrolled in cohorts of 10 at a time. Five regimens were studied: (1) 25 μg every 4 hours, (2) 50 μg every 4 hours, (3) 100 μg every 4 hours, (4) 50 μg every 2 hours, and (5) 75 μg every 4 hours. A total of 46 women were enrolled. Baseline uterine activity approximately doubled with 4 of the regimens and tripled with the highest dosage regimen (100 μg) (P < .001). The 100-μg regimen was truncated due to excessive uterine hyperstimulation (40%). An oral dose of 75 μg of misoprostol given at a 4-hour interval for a maximum of 2 doses is the highest tolerated dose. Randomized, controlled trials will be required before a regimen is employed routinely.