Shoulder dystocia without versus with brachial plexus injury: A case-control study

Objective. To delineate factors that differentiate shoulder dystocia with and without brachial plexus injury (BPI). Study design. A case - control study culled from an established shoulder dystocia database. Cases of shoulder dystocia-related BPI were identified and matched ( 1: 1) with a control group of shoulder dystocia in which BPI did not result. Odds ratios ( OR) and 95% confidence intervals (CI) were calculated. Results. From 1980 to 2002, there were 89 978 deliveries with 46 cases of dystocia and BPI. The rate of dystocia with BPI was 0.5 per 1000 births and of permanent BPI, 0.9/ 10 000 deliveries. The two groups were similar for maternal demographics, diabetes, gestational age, induction, use of epidural, the duration of labor, operative vaginal delivery, rate of macrosomia, and maneuvers used to relieve the dystocia. Fracture of the clavicle occurred significantly less often among those without (2%) vs. with BPI (17%; OR 0.10, 95% CI 0.01, 0.88). Conclusions. Neither antepartum nor intrapartum factors can differentiate the patient who will have shoulder dystocia with vs. without BPI.