Labor induction during vaginal birth after cesarean delivery attempts more than doubled the risk of complete uterine rupture, according to a recent study.

In the retrospective case-control study, published in Acta Obstetricia et Gynecologica Scandinavica, investigators evaluated the risk factors for complete uterine rupture in women attempting vaginal birth following cesarean delivery (VBAC). Conducted across 11 French university hospitals between 2002 and 2018, the study included 31,668 women with a single prior cesarean section who attempted VBAC.

Among the women, 72.9% (n = 23,086) of them achieved a successful vaginal delivery. The overall rate of complete uterine rupture was 0.63%, with 199 cases identified and matched with 396 controls who experienced no rupture.

The investigators analyzed risk factors using logistic regression, stratifying by spontaneous labor and labor induction. In the overall cohort, prior vaginal delivery was associated with a lower risk of uterine rupture (adjusted odds ratio [OR] = 0.3, 95% confidence interval [CI] = 0.2–0.5). Conversely, labor induction increased the risk (adjusted OR = 2.2, 95% CI = 1.4–3.4). Among women with spontaneous labor, additional risk factors included a Bishop score below 6 at admission (adjusted OR = 1.8, 95% CI = 1.0–3.0), arrest of cervical dilation (adjusted OR = 1.8, 95% CI = 1.1–2.9), and oxytocin augmentation (adjusted OR = 2.2, 95% CI = 1.3–3.7). In cases of labor induction, no specific factors reached statistical significance, though suspected macrosomia (birthweight > 4,000 g) showed a trend toward increased risk (adjusted OR = 3.5, 95% CI = 0.95–6.1).

Maternal morbidity was notably higher in cases of uterine rupture, with postpartum hemorrhage occurring in 27.1% of cases compared with 5.1% of controls, and 4% of cases requiring hysterectomy. Neonatal outcomes were also impacted, with 27.5% of neonates born after uterine rupture having a pH of less than 7, and 18.4% requiring intubation.

The study highlighted the associations between labor induction, oxytocin use, and increased risk of uterine rupture in VBAC attempts, particularly among women with unfavorable cervical conditions or suspected macrosomia. The findings emphasized the need for careful labor management to minimize risks and improve maternal and neonatal outcomes.

Full disclosures can be found in the published study.