Risk factors for mediolateral episiotomy at a tertiary hospital: a cross-sectional study.

Objective: The main aim of this study was to assess the associated factors for selective mediolateral episiotomy at a tertiary, academic hospital.

Methods: A retrospective cohort analysis between 2017 and 2019 was performed. The primary outcome was the prevalence of selective mediolateral episiotomy. Independent variables were maternal, intrapartum, and neonatal characteristics. A significance level of 5% was established, and univariate and multivariate analyses with logistic regression models were performed.

Results: From 2,761 vaginal deliveries eligible for inclusion during this period, the prevalence of selective mediolateral episiotomy was 18.7%. Univariate analysis has shown that non-white women were protective factors (OR=0.77 [0.63-0.96]; p=0.02) for episiotomy; primiparity (OR=2.61 [2.12-3.21]; p<0.01), number of vaginal examinations between 6-10 repetitions (OR=3.16 [2.48-4.01]; p<0.01) and 11-20 repetitions (OR=5.40 [3.69-7.90]; p<0.01), longer second stage duration (OR=1.01 [1.00-1.02]; p<0.01), and women with gestational age more than 37 weeks were risk factors. Multivariate analysis reported that second stage duration (AOR=1.01 [1.00-1.03]; p<0.01), primiparity (AOR=2.03 [1.34-3.06]; p<0.01), and number of vaginal examinations between 6-10 repetitions (AOR=2.36 [1.50-3.70]; p<0.01) and 11-20 repetitions (AOR=3.29 [1.74-6.20]; p<0.01) were remained as risk factors for selective mediolateral episiotomy.

Conclusion: A higher number of vaginal examinations during labor (over six repetitions), longer duration of second stage labor, and primiparity were risk factors associated with selective mediolateral episiotomy.