Amniotomy versus expectant management during the active phase of labor defined by the new WHO definition on the duration of labor: A randomized controlled trial.

OBJECTIVE

To compare the labor duration and other maternal and neonatal outcomes between hospitalized women with uncomplicated pregnancies receiving amniotomy at 5 cm cervical dilatation and those not receiving amniotomy.

METHODS

This prospective, randomized controlled trial was conducted at a tertiary hospital between June 2020 and October 2021. The study included low-risk pregnant women with spontaneous onset of labor at term, carrying a single fetus in cephalic presentation and with intact amniotic membranes. When the cervical dilatation reached 5 cm, participants were randomly assigned to receive or not receive amniotomy. Maternal demographics, labor and delivery data, and neonatal outcomes were compared between the two groups.

RESULTS

The amniotomy group had a significantly shorter duration of labor compared with the control group (mean difference 49.4 min, 95% confidence interval [CI] 16.8-81.9, P = 0.003). The following outcomes were not significantly different between the two groups: (1) the need for oxytocin to augment labor; (2) cesarean section rates; (3) the incidence rates of suspected fetal distress and instrumental delivery; and (4) neonatal outcomes.

CONCLUSIONS

Compared with expectant management, amniotomy during the active phase of labor (as newly defined by WHO) can shorten the labor duration without an increased risk of cesarean delivery or other negative consequences. THAI CLINICAL TRIALS REGISTRY (TCTR) (TCTR20200522001): https://www.thaiclinicaltrials.org/show/TCTR20200522001.