Shoulder dystocia recognition: differences in neonatal risks for injury.

Shoulder dystocia (SD) is an event whose current diagnostic approach is based on subjective criteria alone. Since the risk for immediate neonatal morbidity is critically linked to recognition and appropriate management of this obstetric emergency, we hypothesized that infants having injuries consistent with SD are frequently delivered without the intrapartum identification of this condition. A retrospective analysis of 26,033 vaginal births from January 1979 to April 1987 identified 162 maternal cases in which SD was diagnosed during delivery (incidence, 0.62%). Within this subset of patients, 24 neonates (15%) were identified as having either brachial plexus or fractured clavicle injuries associated with delivery. An additional 60 neonates were identified as having similar injuries immediately following delivery but without obstetric recognition of SD. Therefore 71% of all the injured infants were the product of deliveries without SD recognition. A comparison was made of maternal and neonatal variables for three groups (SD, uninjured; SD, injured; unrecognized SD, injured). The SD, injured group distinguishes itself from the other two groups by significant differences in the degree to which variables previously associated with SD are present. Conversely, both other groups are similar in all parameters except for accepted SD maneuvers utilized. These results support our hypothesis that SD is underreported in the obstetric literature and that unrecognized SD is associated with an increased risk of neonatal injury. Efforts to define objectively the threshold forces associated with neonatal injury and to develop SD teaching models should improve this clinical dilemma.