Incremental increases in oxytocin infusion regimens for induction of labor at term in primigravidas: a randomized controlled trial

Abstract

Objective: To compare induction of labor by intravenous oxytocin in regimens increasing incrementally at 15- and 30-minute intervals.

Methods: In a randomized controlled trial, 124 primigravidas requiring induction of labor by oxytocin infusion were randomly allocated to incremental increases at 30-minute intervals (62 patients) or 15-minute intervals (62 patients). The main outcomes assessed were mode of delivery, complications of labor and delivery (precipitate labor, hyperstimulation, postpartum hemorrhage, perineal tears, puerperal pyrexia), and number of days in the hospital.

Results: The 30-minute incremental regimen resulted in less precipitate labor (odds ratio 0.233, 95% confidence interval [CI] 0.042-0.55, chi 2 = 4.133), less uterine hyperstimulation (odds ratio 0.17, 95% CI 0.015-1.906), and reduced length of stay in the hospital (difference in medians 3 days, 95% CI for difference in medians 2-4 days). The induction-delivery interval was longer with 30 minutes (median 8 hours) than with 15 minutes (median 5 hours) (difference in medians 2 hours, 95% CI for difference in medians 0-3 hours). With the 30-minute interval, there was a reduction in the occurrence of postpartum hemorrhage, perineal tears, and puerperal pyrexia, but these differences did not reach statistical significance.

Conclusion: For the induction of labor in primigravidas, 30-minute incremental increases in the infusion rate of oxytocin were superior to a 15-minute incremental protocol in reducing the incidence of hyperstimulation and precipitous labor.