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

ABSTRACT

OBJECTIVE: We designed a dose-finding trial of oral misoprostol administered for labor augmentation. STUDY DESIGN: 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. RESULTS: 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%). CONCLUSION: 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.