Obstetric brachial plexus palsy: a prospective, population-based study of incidence, recovery, and residual impairment at 18 months of age.

Aim The aim of this investigation was to study the incidence of obstetric brachial plexus palsy (OBPP), to prospectively follow the recovery process, to assess the functional outcome at 18 months of age, and to find early prognostic indicators. Method Of the 38 749 children born between 1999 and 2001 in western Sweden, 114 (70 males, 44 females) had an OBPP. Ninety-eight children were examined on six occasions at up to 18 months of age. Muscle strength, range of motion, hand preference, and functional abilities were noted, and the severity of the OBPP was classified. Results The incidence of OBPP was 2.9 per 1000 live births, and the incidence of persisting OBPP was 0.46 per 1000. At 3 months of age, the predictive value of regained elbow flexion for complete recovery was 100%, 99% of shoulder external rotation, and 96% of forearm supination. Most of the 18 children with persisting OBPP could perform functional activities but asymmetries were noted. Five children had a mild, 11 had a moderate, and two had a severe impairment. Three had undergone nerve surgery, one with a mild and two with a severe persisting impairment. Interpretation Most children with an OBPP recover completely. Muscle strength at 3 months of age can be used to predict outcome