Risk factors for episiotomy during vaginal childbirth: A retrospective cohort study in Western China.

Abstract

To assess the incidence rates and risk factors for episiotomy during vaginal childbirth in a Western China context. A retrospective hospital-based cohort study was conducted using computerized data of 3721 singleton vaginal deliveries after 28weeks of gestation. Women who underwent episiotomy were compared with those who did not. The overall prevalence of episiotomy was 44.0% (1636/3721); 52.9% (1458/2756) among primiparas and 18.4% (178/965) among multiparas (P<0.001). Adjusted risk factors significantly associated with episiotomy included primiparity, prolonged second stage of labor, and labor-management personnel. Risk factors specific to primiparas were increasing maternal age (per year) (OR=1.04, 95% CI 1.01 to 1.07, P=0.035), increasing biparietal diameter (per centimeter) (OR=1.40, 95% CI 1.06 to 1.84, P=0.017), first stage of labor beyond 10-hour (OR=1.36, 95% CI 1.10 to 1.68, P=0.005), and birth weight (per 100g) (OR=1.06, 95% CI 1.03 to 1.09, P<0.001). Birth weight resulted in an adjusted risk increase of 6.1% among primiparas for every 100 additional grams of birth weight. For the analysis stratified by labor-management personnel, moderately experienced midwifery was a risk factor of episiotomy (OR=1.76, 95% CI 1.21 to 2.56, P=0.003); midwives with bachelor's degree (OR=1.47, 95% CI 1.15 to 1.88, P=0.002), and obstetricians with doctor's degree (OR=2.00, 95% CI 1.18 to 3.39, P=0.010) were most likely to perform episiotomy. Episiotomy is still commonly performed in Western China. A survey of maternity care professionals' knowledge of and attitudes towards episiotomy is urgently required to explore the complex reasons for conducting episiotomy.