Risk factors for episiotomy: a case-control study

Objective: obtaining information on the factors associated with episiotomy will be useful in sensitizing professionals to the need to minimize its incidence. Therefore, the objective of this study was to evaluate risk factors for episiotomy in pregnant women who had undergone vaginal delivery at a university maternity hospital in northeastern Brazil. Methods: a case-control study was conducted with pregnant women submitted to episiotomy (cases) and pregnant women not submitted to episiotomy (controls) between March 2009 and July 2010 at the Professor Fernando Figueira Integral Medicine Institute (IMIP) in Recife, Brazil, in a ratio of 1 case to 2 controls. The study variables consisted of whether episiotomy was performed, demographic, obstetric and fetal characteristics (primiparity, analgesia, instrumental delivery, fetal distress, etc.), external factors (day and time of delivery, professional attending delivery) and factors directly related to delivery. Odds ratios (OR) and 95% confidence intervals (95%CI) were calculated. Multivariate analysis was performed to determine the adjusted risk of episiotomy. Results: a total of 522 women (173 cases and 349 controls) were included. It was found that deliveries with episiotomy were more likely to have been attended by staff physicians (OR = 1.88; 95%Cl: 1.01 - 3.48), to have required forceps (OR = 12.31; 95%CI: 4.9 - 30.1) and to have occurred in primiparas (OR = 4.24; 9596CI: 2.61 - 6.89). The likelihood of a nurse having attended the delivery with episiotomy was significantly lower (OR = 0.29; 95%C1: 0.16 - 0.55). Conclusion: episiotomy was found to be strongly associated with deliveries attended by staff physicians, with primiparity, and with instrumental delivery, and was less common in deliveries attended by nurses.