Evaluation of the Effect of Body Mass Index on Labor Progress in Mothers Undergoing Epidural Analgesia: A Double-Blind Randomized Clinical Trial

Abstract

The present study evaluates the association between epidural analgesia and the duration of the active phase of labor and pregnancy outcomes in mothers with high body mass index (BMI). All term pregnant women undergoing epidural analgesia for pain-free labor entered the study from September 2016 to March 2020. After recruiting 300 subjects into the study, mothers were categorized into six groups based on their BMI levels. Each BMI sub-group was analyzed regarding the duration of the active phase of labor and delivery mode. In addition, the relationship between BMI and labor outcome and characteristics was studied. Overall, 300 laboring women with epidural analgesia were included. 79.3% had a vaginal delivery, and 20.7% undergo cesarean section. Different BMI sub-groups showed no significant difference regarding the duration of the active phase of labor under epidural analgesia. Cox regression analysis revealed that BMI had no significant effect on the length of the active phase of labor (P=0.787). No significant association was found between BMI and the cesarean delivery rate, uterine atony, maternal pyrexia, neonatal Apgar score, and NICU hospitalization rate. However, BMI was significantly associated with the incidence of dystocia and headache. labor with dystocia exhibited a significantly higher Mother’s BMI (P<0.05). The results suggest no significant association between epidural analgesia and the active phase of labor duration in mothers with high BMI.