Selective versus routine use of episiotomy for vaginal births in Shanghai hospitals, China: a comparison of policies

BACKGROUND: To assess the effects of policy of selective versus routine episiotomy on mother and baby for women delivering vaginally in Shanghai and whether the hospital type has any effect on the outcomes. METHOD: This was a multi-center retrospective cohort study in Shanghai between March 2015 and May 2017. The study population were vaginal births with selective or routine episiotomy (n = 5478) in 20 secondary or tertiary hospitals. Main Outcome Measure was the incidence of severe perineal lacerations. The adjusted odds ratios (aOR) and 95% confidence intervals (CI) were estimated by logistic regression and presented as the effect sizes. All models were stratified by the utilization of level (secondary and tertiary) and type (general and Obstetric) of hospital. RESULTS: The primary outcome was not significantly different between vaginal births with routine and selective episiotomy. Patients with selective episiotomy had a lower risk of postpartum hemorrhage, and newborns in the selective episiotomy group had a lower risk of shoulder dystocia and Neonatal Ward compared to those with routine episiotomy. Newborns in selective episiotomy group had a lower risk of birth injury in tertiary hospital. However, newborns in selective episiotomy group had a higher risk of birth injury in general hospitals. CONCLUSION: Selective episiotomy is safe and can be recommended over routine episiotomy in obstetric and tertiary hospital settings in China. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12884-022-04790-0.