A RANDOMIZED COMPARISON OF 15-MINUTE AND 40-MINUTE DOSING PROTOCOLS FOR LABOR AUGMENTATION AND INDUCTION

Objective: To compare two low-dose oxytocin protocols in terms of feta l distress, uterine hyperstimulation, cesarean delivery rate, maximum dose of oxytocin, and length of labor. Methods: We randomized 865 pati ents into 15-minute (incremental dose 1 mU/minute until 5 mU/minute, t hen 1 or 2 mU/minute) or 40-minute (incremental dose 1.5 mU/minute unt il 7 mU/minute, then 1.5 or 3.0 mU/minute) low-dose protocols. Before oxytocin use, all subjects were stratified according to parity and pur pose of oxytocin, ie, for induction or augmentation of labor. Results: The 40-minute dosing protocol had a significantly lower maximum dose of oxytocin (augmentation, 6.5 versus 8.2 mU/minute, P < .001; inducti on, 11.5 versus 14.5 mU/minute, P < .001), a lower incidence of uterin e hyperstimulation (augmentation, 18.8 versus 31.8%, P < .001; inducti on, 19.1 versus 33.0%, P < .002), and less fetal distress (augmentatio n, 15.5 versus 26.1%, P < .005). No significant differences were found in the cesarean rate or length of labor. Conclusion: A dosing interva l of 40 minutes led to lower incidences of uterine hyperstimulation an d fetal distress, and decreased the maximum dose of oxytocin, without affecting the length of labor or the cesarean rate.