Impact of Gestational Weight Gain on Delivery Outcomes in Women Undergoing Trial of Labour After Caesarean Section: A Cross-Sectional Study

Background: Repeat cesarean deliveries are the primary driver of the global increase in caesarean section (CS) rates. Promoting trial of labour after caesarean (TOLAC) offers an opportunity to reduce unnecessary CS rates. While gestational weight gain (GWG) is a modifiable risk factor influencing maternal outcomes, its impact on TOLAC remains unclear. Objective: To assess the association between abnormal GWG and the risk of failed trial of labour after CS. Methods: A prospective case-control study was conducted at a tertiary care centre in India from January 2021 to December 2022. Women with a prior single CS and term singleton pregnancy undergoing TOLAC were included. Those with failed TOLAC were included as cases (n = 200), and those who had a successful vaginal birth after caesarean (VBAC) (n = 200) were included as controls. GWG was categorised per the Institute of Medicine (IOM) guidelines. Multivariate logistic regression analysis assessed the association between GWG and TOLAC outcomes, adjusting for key confounders. Results: Excessive GWG was not significantly associated with TOLAC failure after adjustment for confounders (adjusted odds ratio (aOR), 95% confidence interval (CI)). A higher pre-pregnancy body mass index (BMI) (aOR, 95% CI) and the need for labour augmentation (aOR, 95% CI) increased the odds of TOLAC failure, whereas a prior successful VBAC reduced the risk. Neonatal outcomes did not differ significantly between groups. Conclusions: In this cohort, excessive GWG did not increase the risk of failure after TOLAC. These findings suggest the EGWG should not deter anyone from offering a TOLAC, even those with higher pre-pregnancy BMI.