The International Network of Obstetric Survey Systems study of uterine rupture: a descriptive multi-country population-based study.

<bold>Objective: </bold>International comparison of complete uterine rupture.<bold>Design: </bold>Descriptive multi-country population-based study.<bold>Setting: </bold>International.<bold>Population: </bold>International Network of Obstetric Survey Systems (INOSS).<bold>Methods: </bold>We merged individual data, collected prospectively in nine population-based studies, of women with complete uterine rupture, defined as complete disruption of the uterine muscle and the uterine serosa, regardless of symptoms and rupture of fetal membranes.<bold>Main Outcome Measures: </bold>Prevalence of complete uterine rupture, regional variation and correlation with rates of caesarean section (CS) and trial of labour after CS (TOLAC). Severe maternal and perinatal morbidity and mortality.<bold>Results: </bold>We identified 864 complete uterine ruptures in 2 625 017 deliveries. Overall prevalence was 3.3 (95% CI 3.1-3.5) per 10 000 deliveries, 22 (95% CI 21-24) in women with and 0.6 (95% CI 0.5-0.7) in women without previous CS. Prevalence in women with previous CS was negatively correlated with previous CS rate (ρ = -0.917) and positively correlated with TOLAC rate of the background population (ρ = 0.600). Uterine rupture resulted in peripartum hysterectomy in 87 of 864 women (10%, 95% CI 8-12%) and in a perinatal death in 116 of 874 infants (13.3%, 95% CI 11.2-15.7) whose mother had uterine rupture. Overall rate of neonatal asphyxia was 28% in neonates who survived.<bold>Conclusions: </bold>Higher prevalence of complete uterine ruptures per TOLAC was observed in countries with low previous CS and high TOLAC rates. Rates of hysterectomy and perinatal death are about 10% following complete uterine rupture, but in women undergoing TOLAC the rates are extremely low (only 2.2 and 3.2 per 10 000 TOLACs, respectively.) TWEETABLE ABSTRACT: Prevalence of complete uterine rupture is higher in countries with low previous CS and high TOLAC rates. [ABSTRACT FROM AUTHOR]