Routine vaginal examination to assess labor progress at 8 compared to 4 h after early amniotomy following Foley balloon ripening in the labor induction of nulliparas: A randomized trial

INTRODUCTION: Our objective was to compare the performance of the first vaginal examination at 8 vs 4 h after amniotomy following Foley ripening in nulliparous labor induction.

MATERIAL AND METHODS: A randomized controlled trial was conducted from June 2021 to January 2022. 210 nulliparas at term for labor induction were randomized: 105 each to first vaginal examination at 8 or 4 h after Foley balloon ripening and amniotomy. Titrated oxytocin infusion was routinely commenced after amniotomy to expedite labor. Primary outcomes were the amniotomy-to-delivery interval (non-inferiority hypothesis) and maternal satisfaction with their allocated labor care (superiority hypothesis) within 24 h after delivery. Analyses performed using t-test, Mann-Whitney U test, and Chi-squared test as appropriate.

RESULTS: The amniotomy-to-delivery interval was mean ± standard deviation 8.7 ± 3.4 vs 8.4 ± 3.7, mean difference 0.4 (97.5% CI: -0.7 to 1.5) hours, p = 0.442 within the pre-specified 2-hour non-inferiority margin, and maternal satisfaction score with allocated labor care was median [interquartile range] 8[7.5-10] vs 8[7.0-10], p = 0.248 for 8 vs 4 h arms, respectively. The amniotomy to first vaginal examination intervals was 5.9 ± 2.3 vs 3.6 ± 1.0 h, p