Intrapartum amnioinfusion for meconium-stained fluid: meta-analysis of prospective clinical trials

Abstract

Objective: To evaluate the effectiveness of intrapartum prophylactic amnioinfusion in pregnancies complicated by meconium-stained amniotic fluid.

Data sources: We identified prospective clinical trials of amnioinfusion in pregnancies complicated by meconium-stained amniotic fluid (AF) published in English by using computerized databases, references in published studies, and index reviews.

Methods of study selection: We analyzed prospective studies of intrapartum amnioinfusion for meconium-stained AF. In every case, group allocation was based exclusively on meconium in AF. Only published studies with clearly documented outcome data were included. The trials were evaluated for meconium below the vocal cords, meconium aspiration syndrome, fetal acidemia, cesarean delivery, and postpartum endometritis. Each trial was evaluated for the quality of its methodology, inclusion and exclusion criteria, adequacy of randomization, amnioinfusion protocols, definition of outcomes, and statistical analyses.

Tabulation, integration, and results: Thirteen studies met inclusion criteria for our systematic review. Odds ratios (ORs) with their 95% confidence intervals (CIs) were calculated for each outcome. Estimates of ORs and risk differences for dichotomous outcomes were calculated using random and fixed-effects models. We tested for homogeneity across the studies. We found that intrapartum amnioinfusion significantly reduced the frequency of meconium aspiration syndrome (OR 0.30; 95% CI 0.19, 0. 46), of meconium below the vocal cords, and neonatal acidemia. Subjects allocated to receive amnioinfusion also had a significantly lower overall cesarean rate (OR 0.74, 95% CI 0.59, 0.93) without increased postpartum endometritis.

Conclusion: Amnioinfusion in cases of meconium-stained fluid significantly improves neonatal outcome, lowers the cesarean delivery rate, and does not increase the postpartum endometritis rate.