Nitroglycerine for retained placenta: a meta-analysis of randomized controlled trials

Objective: To evaluate the effect of nitroglycerine on placenta delivery after retained placenta DESIGN: Systematic review with meta-analysis DATA SOURCES: MEDLINE, PROSPERO, Scopus, ClinicalTrials.gov, EMBASE, Sciencedirect, the Cochrane Library, Scielo were searched from their inception until February 2024. Eligibility criteria for selecting studies: We included all randomized clinical trials comparing use of nitroglycerine (i.e. intervention group) with placebo or with no treatment (i.e. control group) given for retained placenta after vaginal delivery. Data synthesis: The primary outcome was rate of manual removal of the placenta. The summary measures were reported as relative risk (RR) or as mean difference (MD) with 95% of confidence interval (CI). Results: Five trials, including 1,362 pregnancies, were analyzed. The quality of the RCTs included was moderate. Pooled results showed that administration of nitroglycerine in women with retained placenta after vaginal delivery was associated with similar incidence of manual removal compared to control (87% vs 89%; RR 0.92, 95% CI 0.75 to 1.13). We also found similar mean postpartum blood loss, and no significant differences in the incidence of drop of hb > 15 or 30%, need for uterotonics. Conclusions: Use of nitroglycerine in women with retained placenta after vaginal delivery did not reduce the use of manual removal of the placenta.