Risks and Outcomes of Uterine Rupture in Women With and Without a Trial of Labour.

Objectives: The study aimed to evaluate the maternal and neonatal outcomes in patients who experienced uterine rupture, comparing those who underwent a trial of labour to those who did not.

Methods: A population-based retrospective study was conducted in a tertiary university medical centre from 2008 to 2019. The cohort consisted of all women who were diagnosed with uterine rupture during cesarean delivery (CD) or laparotomy. Patients with 1 previous CD who underwent a trial of labour (TOLAC group) were compared against patients who had a history of CD in whom no trial of labour occurred, and/or against patients who had no prior CD in whom a ruptured uterus was diagnosed during or following delivery (no-TOLAC group). Patients with uterine scar dehiscence were excluded.

Results: Of 103 542 women who gave birth during the study period, 10 325 had a previous CD. Uterine rupture occurred in 95 cases: 55 among patients who had undergone TOLAC (0.98%) and 40 (0.85%) without trial of labour. Compared with the TOLAC group, the subgroup of women with a single prior CD who did not attempt TOLAC (n = 16) had a higher rate of neonatal intensive care unit admission (56.3% vs. 21.7%, OR 4.15; 95% CI 1.3-13.3, P = 0.01) and adverse composite maternal outcomes (blood transfusion, urinary bladder injury, and/or intensive care unit admission) (75% vs. 30.9%, OR 6.7; 95% CI 1.8-23.8, P < 0.01). There was no neonatal or maternal death in any group.

Conclusions: Despite the higher incidence of uterine rupture in women undergoing TOLAC, outcomes are less favourable when rupture occurs outside the trial of labour and if the uterus is unscarred.