Trial of labor after cesarean outcomes with excessive gestational weight gain

The success of vaginal birth after cesarean section (VBAC) has been correlated with a variety of maternal characteristics such as age, ethnicity, and body mass index (BMI, calculated as weight in kilograms divided by height in meters squared). The patient’s BMI just prior to delivery has been shown to be a better prognostic indicator of success than pre-pregnancy BMI. Gestational weight gain was previously associated with a decreased rate of successful VBAC. More recent research has not supported such an association. The objective of our study was to further validate these findings with a larger population. We performed a retrospective cohort study of women undergoing trial of labor after cesarean (TOLAC) at our institution from January 2010 to December 2019. Women were divided into three groups based on weight gain in pregnancy as compared to the American College of Obstetrics and Gynecology (ACOG) recommendations (i.e. < 25 pounds (lbs), 25-35 lbs, > 35 lbs). We further subdivided the pregnancies between term and preterm deliveries. The primary outcome was a successful VBAC. Of 1087 patients attempting a TOLAC, 772 (71%) were successful and 315 (29%) failed VBAC. When grouped according to ACOG weight gain recommendations, 303 (31%) women were below ACOG guidelines, 318 (33%) met guidelines, and 339 (35%) exceeded guidelines. There was no difference in the rate of VBAC success among the three groups. When counseling patients, providers should still promote healthy dietary habits but should not correlate excess weight gain with chance of TOLAC success