Evolution of Episiotomy Incidence and Obstetric Anal Sphincter Injury Over 10 Years: A Mixed-Methods Study

To assess the association between the decrease in the use of episiotomy and the incidence of obstetric anal sphincter injuries (OASIS) over a 10-year period and understand their reasons by interviewing obstetricians and midwives.

Mixed-methods study.

A tertiary university public maternity hospital, Paris, France.

All patients who delivered vaginally between January 2012 and December 2021 in the maternity hospital and 20 interviews with obstetrician-gynaecologists and midwives.

Quantitative data analysis using a multivariate logistic regression model, stratifying on the mode of delivery. Semi-structured interview with 20 obstetricians and midwives, with an interview guide.

Obstetric anal sphincter injuries.

The quantitative study of 37 942 women (16.1% of whom had an episiotomy and 1.4% OASIS) shows that, the incidence of episiotomy decreased from 25% to 7.6% over this 10-year period. Allow on the known risk factors for OASIS, we demonstrate that its incidence rose (adjusted odds ratio 1.35, 95% confidence interval 1.09-1.67) for the years in which the episiotomy incidence fell below 10% for the overall population. The interviews showed professionals' apparent awareness that the decreased incidence in episiotomy (achieved by changes in departmental policy, redefining its benefit/risk balance and acquiring new skills to manage the expulsion phase) could lead to an increased incidence of OASIS.

Decreasing the episiotomy incidence appears to be associated with a rising incidence of OASIS. The optimal incidence of episiotomy remains controversial in the literature and among professionals.