Oxytocin and vaginal dinoprostone in labor induction: A systematic review and meta-analysis

The comparison between prostaglandin E2 (PGE2) and oxytocin and for induction of labor (IOL) remains controversial.

The present study aimed to determine the safety and efficacy of these two agents in IOL.

PubMed, Embase, Web of Science, Cochrane Library, and ClinicalTrials.gov. from the establishment of the database to April 23, 2023.

A search was conducted with keywords "labor, induction, prostaglandin E2/PGE2/dinoprostone, and oxytocin". Only randomized clinical trials comparing oxytocin and vaginal dinoprostone in women who were at least late preterm (gestational age [GA] ≥34 weeks), singleton pregnant, and had intact membranes were enrolled for further meta-analysis.

We conducted both a descriptive analysis and a meta-analysis. In the meta-analysis, we utilized the Mantel-Haenszel random effects model to analyze dichotomous data, employing the relative risk (RR) as the effect measure along with 95% confidence intervals (CIs). The study quality was evaluated using Cochrane Collaboration's risk of bias assessment tool (RoB 2). A random-effects model was applied for the meta-analysis.

After screening 3303 articles from five databases, a total of nine randomized controlled studies composed of 1071 patients were included. Our analysis included 534 patients in the PGE2 group and 537 patients in the oxytocin group. The pooled estimate of vaginal deliveries following PGE2 induction stood at 84.2%, while after oxytocin induction, it was 79.8%. The meta-analysis showed no statistical difference between the two groups in terms of the rate of vaginal delivery (pooled RR, 1.05; 95% CI: 0.95-1.16; P value for Q, 0.001; I², 71.14%), cesarean section (pooled RR, 0.84; 95% CI: 0.52-1.35; P value for Q, 0.007; I², 61.69%) and induction-delivery interval (pooled standard mean difference, 0.09; 95% CI: -0.67 to 0.85; P value for Q, 0.000; I², 96.45%). Since the results for fetal distress and uterine hyperstimulation were consistent across all enrolled studies, no further meta-analysis was conducted.

When amalgamating the available literature, it implies that oxytocin was found to have similar effects as PGE2 on delivery outcomes and safety concerns in pregnant women with GA ≥36 weeks. Although the uterine cervix was unfavorable, both low and high doses of oxytocin were feasible for IOL.