OBJECTIVE: To evaluate the effects of prior
single-layer compared with double-layer closure on the risk of uterine
rupture.

METHODS: A multicenter, case–control study was
performed on women with a single, prior, low-transverse cesarean who
experienced complete uterine rupture during a trial of labor. For each
case, three women who underwent a trial of labor without uterine rupture
after a prior low-transverse cesarean delivery were selected as control
participants. Risk factors such as prior uterine closure, suture
material, diabetes, prior vaginal delivery, labor induction, cervical
ripening, birth weight, prostaglandin use, maternal age, gestational
age, and interdelivery interval were compared between groups.
Conditional logistic regression analyses were conducted.

RESULTS: Ninety-six cases of uterine rupture,
including 28 with adverse neonatal outcome, and 288 control participants
were assessed. The rate of single-layer closure was 36% (35 of 96) in
the case group and 20% (58 of 288) in the control group (P<.01).
In multivariable analysis, single-layer closure (odds ratio [OR] 2.69;
95% confidence interval [CI] 1.37–5.28) and birth weight greater than
3,500 g (OR 2.03; 95% CI 1.21–3.38) were linked with increased rates of
uterine rupture, whereas prior vaginal birth was a protective factor (OR
0.47; 95% CI 0.24–0.93). Single-layer closure was also related to
uterine rupture associated with adverse neonatal outcome (OR 2.89; 95%
CI 1.01–8.27).

CONCLUSION: Prior single-layer closure carries more
than twice the risk of uterine rupture compared with double-layer
closure. Single-layer closure should be avoided in women who could
contemplate future vaginal birth after cesarean delivery.

LEVEL OF EVIDENCE: II