Sexual violence and mode of delivery: a population-based cohort study.

OBJECTIVE This study aimed to explore the association between sexual violence and mode of delivery. DESIGN National cohort study. SETTING Women presenting for routine ultrasound examinations were recruited to the Norwegian Mother and Child Cohort Study between 1999 and 2008. POPULATION A total of 74,059 pregnant women. METHODS Sexual violence was self-reported during pregnancy using postal questionnaires. Mode of delivery, other maternal birth outcomes and covariates were retrieved from the Medical Birth Registry of Norway. Risk estimations were performed using multivariable logistic regression analysis. MAIN OUTCOME MEASURES Mode of delivery and selected maternal birth outcomes. RESULTS Of 74,059 women, 18.4% reported a history of sexual violence. A total of 10% had an operative vaginal birth, 4.9% had elective caesarean section and 8.6% had an emergency caesarean section. Severe sexual violence (rape) was associated with elective caesarean section, adjusted odds ratio (AOR) 1.56 (95% CI 1.18-2.05) for nulliparous women and 1.37 (1.06-1.76) for multiparous women. Those exposed to moderate sexual violence had a higher risk of emergency caesarean section, AOR 1.31 (1.07-1.60) and 1.41 (1.08-1.84) for nulliparous and multiparous women, respectively. No association was found between sexual violence and operative vaginal birth, except for a lower risk among multiparous women reporting mild sexual violence, AOR 0.73 (0.60-0.89). Analysis of other maternal outcomes showed a reduced risk of episiotomy for women reporting rape and a higher frequency of induced labour. CONCLUSIONS Women with a history of rape had higher odds of elective caesarean section and induction and significantly fewer episiotomies.