Birth injury in a subsequent vaginal delivery among women with a history of shoulder dystocia

Aim: To examine risk factors for birth injury in a subsequent vaginal delivery among women with a prior delivery complicated by shoulder dystocia. Methods: Population-based retrospective cohort study, Washington State (1987-2007). Logistic regression was used to assess risk factors associated with subsequent birth injury. Results: Of 9232 women who met inclusion criteria, 223 (2.4%) had a subsequent vaginal delivery with birth injury. Birth injury in an index delivery, adjusted odds ratio (aOR) 2.6 [95% confidence interval (CI) 1.7-4.1] and factors in subsequent delivery: birth weight ≥4000 g, aOR 4.4 (95% CI: 3.0-6.3), gestational diabetes, aOR 1.9 (95% CI: 1.2-3.2), Hispanic ethnicity aOR 1.9 (95% CI: 1.2-2.9), and maternal obesity, aOR 1.8 (95% CI: 1.3-2.6) were associated with birth injury. Conclusion: Among women with prior delivery complicated by shoulder dystocia, the risk factors identified in this study should be carefully considered prior to deciding upon route of delivery - cesarean vs. vaginal delivery.