Incidence of vaginal birth–related rupture of the pubic symphysis: A nationwide register study in Finland from 1998 to 2018

Background and purpose: To assess the incidence of vaginal birth -related rupture of the pubic symphysis in Finland from 1998 to 2018. Methods: A retrospective cohort study using nationwide data from the Finnish Care Register for Health Care and the Finnish Medical Birth Register. As participants we included all ≥ 22-week pregnancies of women aged between 15 and 49 years from January 1, 1998 to December 31, 2017. Pubic symphysis rupture was classified based on the ICD-10 code S33.4 and operations were gathered with pelvis-specific operation codes of the Nordic NOMESCO-classification. Incidence per 100 000 deliveries with 95% confidence intervals (CI) was calculated for symphysis rupture and surgery using Poisson’s exact test. Results: For a total 1 175 326 deliveries, a total of 9 pubic symphysis ruptures occurred during the intrapartum and puerperal periods. All ruptures occurred after vaginal delivery. Of these, 4 ruptures were treated operatively. The incidence of rupture for vaginal delivery was 0.9 per 100 000 deliveries (CI 0.1 to 1.0). No perinatal mortality was observed. Conclusions: Birth -related ruptures of the pubic symphysis are rate events and are mostly associated with vaginal delivery with most ruptures being treated conservatively.