Demographic Disparities in Brachial Plexus Birth Injury [ID 2683383

Abstract

INTRODUCTION: Black and Hispanic birthing individuals are at increased risk of delivering an infant with a brachial plexus birth injury (BPBI), but the reasons for these disparities are unclear. We evaluated the association of maternal race/ethnicity with established and suspected risk factors for BPBI to determine if these factors mediate these disparities. METHODS: Institutional review board approval was obtained for this retrospective cohort study of all live births occurring in California-licensed hospitals from 1996 to 2012. Multiple logistic regression was used to model adjusted associations of maternal race and ethnicity with an infant born with BPBI. Causal mediation analyses evaluated established and suspected risk factors for BPBI (obesity, diabetes, gestational diabetes, shoulder dystocia, macrosomia, prolonged second stage of labor, gestational age, post-term, vaginal delivery, insurance status, inadequate prenatal care) as potential mediators of the BPBI–maternal race/ethnicity relationship. RESULTS: The cohort included 6,278,562 births, with 7,762 BPBI. Although Black birthing individuals had an increased risk of obesity (adjusted odds ratio [aOR] 2.48) and diabetes (aOR 1.59) compared to non-Blacks, they had a lower risk of shoulder dystocia (aOR 0.76), macrosomia (aOR 0.60), prolonged second-stage labor (aOR 0.33), precipitous labor (aOR 0.88), and vaginal delivery (aOR 0.79). Blacks had an increased risk of inadequate prenatal care (aOR 1.26) and being underinsured (aOR 1.30). The combination of these factors explained only 16.3% of the increased risk for BPBI in Black people. Findings were similar in Hispanic individuals. CONCLUSION: The increased risk of BPBI in Black and Hispanic individuals is only modestly explained by known risk factors. Prenatal care utilization and socioeconomic factors may play a role.