Risk Factors for Shoulder Dystocia: the Impact of Mother's Race and Ethnicity.

Shoulder dystocia is a rare but severe birth trauma where the neonate's shoulders fail to deliver after delivery of the head. Failure to deliver the shoulders quickly can lead to severe, long-term injury to the infant, including nerve injury, skeletal fractures, and potentially death. This observational study examined shoulder dystocia risk factors by race and ethnicity using a sample of 19,236 pregnant women who presented for labor and delivery from July 1, 2010 until June 30, 2013 at five locations. Multivariate analyses were used to identify risk factors associated with shoulder dystocia occurrence in racial/ethnic groups with high incidence rates. For White non-Hispanic mothers, the strongest risk factors were delivering past 40 weeks' gestation (odds ratio [OR] = 2.4; 95% confidence interval [CI] = 1.5, 3.9; p < .01) and use of epidural anesthesia during delivery (OR = 4.4; 95% CI = 3.0, 6.4; p < .01). Among Black non-Hispanic mothers, the risk factors with the greatest impact were use of epidural (OR = 5.3; 95% CI = 3.2, 8.7; p < .01) and having gestational diabetes and controlling the condition with insulin (OR = 4.6; 95% CI = 1.5, 13.8; p < .01). Additionally, among Hispanic mothers, having Spanish as primary language increased shoulder dystocia likelihood compared to those who did not cite it as their primary language (OR = 2.3; 95% CI = 1.1, 4.6; p < .05). This study provides evidence that risk factors for a labor and delivery condition can vary significantly across racial and ethnic subgroups. These differences emphasize the importance of evaluating risk by population subgroups and might provide a basis for labor and delivery clinicians to enhance personalized medicine to reduce adverse events.