Medline ® Abstracts for References 8,9

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.

OBJECTIVE: To describe the trend in the rate of shoulder dystocia over twenty-four years and identify the risk factors related to the occurrence of dystocia.

METHODS: Data was obtained from Maryland State regarding all vaginal deliveries that occurred during six different time periods at five-year intervals since 1979. Trends in the rate of shoulder dystocia, episiotomy, forceps and vacuum delivery were examined.

RESULTS: There were a total of 277 974 vaginal deliveries. The overall rate of shoulder dystocia was 1.29% (n = 3590). Induction of labor (adjusted OR 1.2, 1.1-1.3), presence of diabetes (gestational (OR 1.9, 1.7-2.3) or pre-gestational (OR 3.8, 2.7-5.4)), fetal macrosomia (OR 5.1, 4.1-6.3) use of episiotomy (OR 1.6, 1.5-1.8), forceps (OR 1.3, 1.0-1.8) or vacuum (OR 2.3, 2.0-3.9) at delivery were associated with a higher rate of shoulder dystocia. TREND: There was an increase in the rate of shoulder dystocia from 0.2% in 1979 to 2.11% in 2003. In addition there was a drop in the overall episiotomy rate from 73.67% to 23.94% and increase in the use of vacuum from 0.1% to 8.36%.

CONCLUSION: The rate of shoulder dystocia has increased by 10 fold during the study period. The use of episiotomy either at spontaneous delivery or instrumental delivery does not appear to decrease the occurrence of shoulder dystocia.