Objective: To investigate trends in the incidence of shoulder dystocia, methods used to overcome the obstruction, and rates of maternal and neonatal morbidity.
Methods: Cases of shoulder dystocia and of neonatal brachial plexus injury occurring from 1991 to 2005 in our unit were identified. The obstetric notes of cases were examined, and the management of the shoulder dystocia was recorded. Demographic data, labor management with outcome, and neonatal outcome were also recorded for all vaginal deliveries over the same period. Incidence rates of shoulder dystocia and associated morbidity related to the methods used for overcoming the obstruction to labor were determined.
Results: There were 514 cases of shoulder dystocia among 79,781 (0.6%) vaginal deliveries with 44 cases of neonatal brachial plexus injury and 36 asphyxiated neonates; two neonates with cerebral palsy died. The McRoberts' maneuver was used increasingly to overcome the obstruction, from 3% during the first 5 years to 91% during the last 5 years. The incidence of shoulder dystocia, brachial plexus injury, and neonatal asphyxia all increased over the study period without change in maternal morbidity frequency.
Conclusion: The explanation for the increase in shoulder dystocia is unclear but the introduction of the McRoberts' maneuver has not improved outcomes compared with the earlier results.
Level of evidence: II.