Risk factors for obstetric anal sphincter injury: an exploratory Norwegian regional cohort study including amniotomy as a potential novel determinant

Based on systematically collected data from our regional birth registry, this cohort study confirmed the association between established risk factors for obstetric anal sphincter injury, such as instrumental vaginal delivery. However, we could not identify amniotomy as a risk factor for obstetric anal sphincter injury, possibly due to changes in clinical practice and potential data limitations.