Aim: To validate risk factors and a nomogram prediction model for the failure of a trial of labor after cesarean section (TOLAC) in a Chinese population.
Methods: We included women who tried TOLAC between January 2017 and May 2019, grouped according to the success/failure of TOLAC. The patients were randomized 3:1 into the development and validation sets. Multivariable logistic regression analyses were used to develop a nomogram prediction model for TOLAC failure.
Results: In total, 535 (86.3%) of the women (n = 620) aged 29-34 years had a successful vaginal birth after cesarean (VBAC). All women had a fully healed previous uterine incision. The univariable analyses showed that the cephalopelvic score (p < 0.001), BMI (p = 0.001), full engagement into the pelvis (p < 0.001), Bishop cervical maturity score (p < 0.001), and estimated fetal weight at admission (p < 0.001) could enter the multivariable model. Furthermore, the multivariable analysis showed that the cephalopelvic score (OR = 0.42, 95%CI: 0.23-0.77, p = 0.005), full engagement in the pelvis (OR = 0.16, 95%CI: 0.08-0.33, p < 0.001), and Bishop cervical maturity score (OR = 0.46, 95%CI: 0.35-0.59, p < 0.001) were independent predictors of the failure of TOLAC.
Conclusion: This study proposes a nomogram that can assess the risk of failure of TOLAC in Chinese pregnant women. The statistical model could help clinicians know the likelihood of successful TOLAC in the clinical setting.
Keywords: cesarean section; nomogram; prediction; trial of labor after a cesarean; vaginal birth.
© 2022 The Authors. Journal of Obstetrics and Gynaecology Research published by John Wiley & Sons Australia, Ltd on behalf of Japan Society of Obstetrics and Gynecology.