Preterm Cesarean Delivery and Safety of Subsequent Delivery: Risk of Uterine Rupture and Other Maternal and Neonatal Outcomes-Multicenter Retrospective Cohort Study.

Background/

Objectives: The safety of trial of labor after cesarean (TOLAC) following prior preterm low-segment transverse cesarean delivery (pCD) was compared to that following term low-segment transverse cesarean delivery (tCD) in terms of the rate of uterine rupture (UR) and adverse maternal and neonatal outcomes.

Methods: A multicenter retrospective cohort study evaluated the delivery outcomes among women with a prior primary pCD and those with a primary tCD. The primary outcome was UR, defined as a full-thickness uterine wall defect. The secondary outcomes included maternal and neonatal morbidities. Chi-square, Fisher's exact test, and Mann-Whitney tests, with the results reported as means ± SDs or medians + interquartile ranges (IQRs), were employed.

Results: The cohort comprised 5340 women, including 186 with a prior pCD and 5154 with a prior tCD. The median gestational age at pCD was 28 weeks, compared to 39 weeks for tCD. Women in the pCD group had higher rates of hypertensive disorders (20.4% vs. 2.5%; p < 0.001). No significant difference in UR incidence was observed at subsequent delivery (0% vs. 0.6%; p = 0.3). However, the pCD group had higher rates of subsequent preterm delivery (19.9% vs. 4.7%; p < 0.01) and vaginal birth after cesarean (VBAC) success (86.1% vs. 77.3%; p = 0.015). Adjusted analyses showed no significant association between pCD and composite adverse neonatal outcomes (OR = 0.796, 95% CI [0.487-1.301]; p = 0.363).

Conclusions: This study underscores the safety of trial of labor after a primary preterm cesarean delivery, indicating no increased risk of uterine rupture compared to term cesarean deliveries. Care should be directed toward lowering subsequent preterm delivery and its associated risks.