299: Association of maternal body mass index with shoulder dystocia management

Abstract

To evaluate maneuvers associated with shoulder dystocia resolution in women with a body mass index (BMI) >35 kg/m2 compared to those with BMI < 35 kg/m2. This is a retrospective cohort of women who delivered between September 2014 and August 2018 at a tertiary care center and whose delivery was complicated by shoulder dystocia. The proportion of patients who underwent a maneuver beyond McRoberts and suprapubic pressure was compared between women with admission BMI >35 vs < 35 kg/m2. Secondary outcomes included total number of maneuvers, specific maneuvers performed, final maneuver prior to delivery, maternal pelvic trauma and length of dystocia. Continuous and categorical variables were evaluated using Wilcoxon rank sum and Fisher’s exact test. Relative risks were calculated with a confidence interval (CI) of 95% being considered significant. Of the 481 women meeting study criteria, 12 were excluded due to lack of informative data. Women with a BMI >35 (n=159, 33.9%), when compared to those with a BMI < 35 (n=310, 66.1%), were more likely to have gestational diabetes treated with medication (RR 2.5, CI 1.29-4.73). Other demographic factors were similar. Women with a BMI >35 were more likely to undergo a maneuver beyond McRoberts and suprapubic pressure (RR 1.19, CI 1.03-1.37), episiotomy (RR 1.87, CI 1.12-3.14) and attempted delivery of the posterior arm (RR 1.46, CI 1.19-1.80). They also had a higher mean total of maneuvers performed (2.2 vs 1.9 p=value 0.007) and posterior arm delivery was more likely to be the final maneuver prior to delivery (RR 1.66, CI 1.23-2.25). Length of dystocia and maternal pelvic trauma were similar regardless of BMI. BMI >35, compared to a BMI < 35, is associated with performance of a maneuver beyond McRoberts and suprapubic pressure as well as episiotomy during shoulder dystocia. Delivery of the posterior arm is also more often the final maneuver prior to delivery in this group. Further data is needed to evaluate if shoulder dystocia management should be individualized for maternal BMI.