The WHO (World Health Organization) recommends that the percentage of perineal incisions should not exceed 10%, indicating that this is a good goal to achieve, despite the fact that it is still a frequently used medical intervention in Poland. The risk factors for perineal incision that have been analyzed so far in the literature allow, among others, to limit the frequency of performing this procedure. Are they still valid? Have there been new risk factors that we should take into account? We have conducted this study to find the risk factors for performing perineal incision that would reduce the frequency of this procedure. The aim of the study was to check whether the risk factors that were analyzed in the literature are still valid, to find new risk factors for perineal incisions and to compare them among Polish women. This was a single-center retrospective case-control study. The electronic patient records of Saint Sophia's Hospital in Warsaw, Poland, a tertiary hospital was used to create an anonymous retrospective database of all deliveries from 2015 to 2020. The study included the analysis of two groups, the study group of patients who had had an episiotomy, and the control group-patients without an episiotomy in cases where an episiotomy was indicated. A logistic regression model was developed to assess the risk factors for perineal laceration. Independent risk factors for episiotomy in labor include oxytocin use in the second stage of labor (OR (Odds Ratio) = 6.00; 95% CI (Confidence Interval): 4.76-7.58), the supply of oxytocin in the first and the second stage of labor (OR = 3.18; 95% CI: 2.90-3.49), oxytocin use in the first stage of labor (OR = 2.72; 95% CI: 2.52-3.51), state after cesarean section (OR = 2.97; 95% CI: 2.52-3.51), epidural anesthesia use (OR = 1.77; 95% CI: 1.62-1.93), male gender (OR = 1.10; 95% CI: 1.02-1.19), and prolonged second stage of labor (OR = 1.01; 95% CI: 1.01-1.01). A protective factor against the use of an episiotomy was delivery in the Birth Centre (OR = 0.43; 95% CI: 0.37-0.51) and mulitpara (OR = 0.31; 95% CI: 0.27-0.35). To reduce the frequency of an episiotomy, it is necessary consider the risk factors of performing this procedure in everyday practice, e.g., limiting the use of oxytocin or promoting alternative places of delivery.
Keywords: episiotomy; risk factors; vaginal birth.