Oxytocin augmentation of labor: a comparison of 15- and 30-minute dose increment intervals.

Two different regimens for oxytocin augmentation of labor were compared retrospectively in two institutions. In one regimen, the interval between dose increments was 15 minutes; in the other it was 30 minutes. All study patients were nulliparous and had uncomplicated pregnancies in spontaneous active labor; the 15-minute group consisted of 92 patients and the 30-minute group had 82 patients. No differences were demonstrated in age, dilation when oxytocin administration started, length of oxytocin administration, cesarean section rate, complications of delivery, birth weight, or Apgar scores. The maximal oxytocin dose in the 30-minute interval group was significantly lower. This group also had the oxytocin infusion stopped for evidence of uterine hyperstimulation and/or abnormal fetal heart rate tracing significantly less often (6.9% for the 30-minute interval versus 17.8% for the 15-minute interval; P = .0017). Overall, these results suggest that the longer interval does not increase the length of labor but decreases the incidence of uterine hyperstimulation.