241 Association of Parity and Previous Birth Outcome With Brachial Plexus Birth Injury Risk

Abstract

OBJECTIVES/GOALS: To evaluate the association of maternal delivery history with a brachial plexus birth injury (BPBI) risk in subsequent deliveries, and to estimate the effect of subsequent delivery method on BPBI risk. METHODS/STUDY POPULATION: We conducted a retrospective cohort study of all livebirth deliveries occurring in California-licensed hospitals from 1996-2012. The primary outcome was recurrent BPBI in a subsequent pregnancy. The exposure was prior delivery history (parity, shoulder dystocia in a previous delivery, or previously delivering an infant with BPBI). Multiple logistic regression was used to model adjusted associations of prior delivery history with BPBI in a subsequent pregnancy. The adjusted risk (AR) and adjusted risk difference (ARD) for BPBI between vaginal and cesarean delivery in subsequent pregnancies were determined, stratified by prior delivery history, and the number of cesarean deliveries needed to prevent one BPBI was determined. RESULTS/ANTICIPATED RESULTS: Of 6,286,324 infants delivered by 4,104,825 individuals, 7,762 (0.12%) were diagnosed with a BPBI. Higher parity was associated with a 5.7% decrease in BPBI risk with each subsequent delivery (aOR 0.94, 95%CI 0.92, 0.97). Previous shoulder dystocia or BPBI were associated with 5-fold (aOR=5.39, 95%CI 4.10, 7.08) and 17-fold increases (aOR=17.22, 95%CI 13.31, 22.27) in BPBI risk, respectively. Among individuals with a history of delivering an infant with a BPBI , cesarean delivery was associated with a 73.0% decrease in BPBI risk (aOR=0.27, 95%CI 0.13, 0.55), compared with an 87.9% decrease in BPBI risk (aOR=0.12, 95%CI 0.10, 0.15) in individuals without this history. Among individuals with a previous history of BPBI, 48.1 cesarean deliveries are needed to prevent one BPBI. DISCUSSION/SIGNIFICANCE: Parity, previous shoulder dystocia, and previously delivering a BPBI infant are associated with future BPBI risk. These factors are identifiable prenatally and can inform discussions with pregnant individuals regarding BPBI risk and planned mode of delivery.