Brachial plexus birth palsy: incidence, natural-course, and prognostic factors during the first year of life.

Predictors of a longer course of recovery were the presence of shoulder dystocia (p < 0.04) and right-sided palsy (p < 0.02). Birth weight, neonatal head circumference, and sex were not correlated with outcome. Future reports of BPBP should differentiate between infants showing early recovery from those with true BPBP.