Fetomaternal outcome of scarred uterine rupture compared with primary uterine rupture: a retrospective cohort study

Literature comparing maternal and perinatal outcomes among women with scarred and primary uterine rupture are limited. Therefore, the study aimed to compare maternal and perinatal outcomes and associated risk factors of uterine rupture among scarred and unscarred uterus.

This retrospective cohort study was performed at a large tertiary care of India between July 1, 2011 and June 30, 2020. We analysed all the cases of complete uterine rupture beyond the 20th week of gestation. The outcome measures were live birth rate, perinatal mortality, maternal mortality and morbidity.

A total of 115 complete uterine ruptures were noted in 148,102 pregnancies. Of those 115 uterine ruptures, 89 (77.3 %) uterine ruptures occurred in women with a history of caesarean delivery, and 26 (22.6 %) uterine ruptures occurred in primary uterine rupture. The primary uterine rupture group had a significantly higher incidence of lower parity, breech presentation and mean birth weight. The live birth rate (68.18% vs. 42.85 %; p=0.04) was significantly higher in the scarred group, and the stillbirth rate (57.14% vs. 31.86 %; p=0.009) was significantly higher in the primary uterine rupture group. Hypoxic ischemic encephalopathy, APGAR score, and neonatal intensive care unit admission were comparable. Postpartum haemorrhage, blood transfusion, severe acute maternal morbidity and intensive care unit stay were more frequently reported in the primary uterine rupture group.

The maternal and perinatal outcomes appear less favourable among women with primary uterine rupture than scarred uterine rupture.