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

OBJECTIVE: To assess the incidence rates and risk factors for episiotomy during vaginal childbirth in a Western China context.

METHODS: A retrospective hospital-based cohort study was conducted using computerized data of 3721 singleton vaginal deliveries after 28 weeks of gestation. Women who underwent episiotomy were compared with those who did not.

RESULTS: 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 100 g) (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.

CONCLUSION: 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.