Obstetrical anal sphincter injury and unnecessary episiotomy are both associated with anal incontinence 8 years after childbirth: A nationwide database analysis

Objective To assess the relationship between anal incontinence (AI) 8 years after childbirth and the occurrence of obstetrical anal sphincter injuries (OASIS) and/or performance of an episiotomy during childbirth. Methods This is a nationwide database analysis performed on two national medico-administrative databases, including all the women aged 18 years or older who delivered infants in France in 2012. The main outcome measure was AI in the 8 years after delivery. Results Of the 163 443 perineal tears reported, 0.47% were grade 3 (n = 3173) and 0.08% were grade 4 (n = 579); 8938 women experienced AI (1.33%) and 261 women experienced severe AI (0.04%). Episiotomies performed in the absence of risk factors for OASIS were significantly associated with an increased risk of AI (odds ratio [OR] 1.59, 95% confidence interval [CI]1.49-1.69; P < 0.001). Grade 3 and 4 OASIS also significantly increased the risk of AI and severe AI. Mediolateral episiotomy was preventive of OASIS when performed in women at risk (OR 0.26, 95% CI 0.23-0.30; P < 0.001) but contributed to OASIS in the absence of risk (OR 2.18, 95% CI 1.98-2.40; P < 0.001). Conclusion OASIS present a risk factor for AI. Episiotomies could reduce the occurrence of OASIS, but they could also increase the risk of long-term AI in the absence of risk factors for OASIS.