Perinatally acquired brachial plexus palsy--a persisting challenge.

The aim of this investigation was to study the contemporary pattern of perinatally acquired brachial plexus palsy (BPP) in Sweden. National incidence data were collected from the Swedish Medical Birth Registry. The clinical pattern of BPP was studied in the county of Skaraborg. All children (n = 52) with confirmed neonatal BPP in 1981-89 were assessed 4-14 y after birth using routine neonatal and follow-up documentation for retrospective analysis and an assessment battery for the clinical evaluation of impairment. The mothers' recollection of the birth process was recorded by interview and compared with two control groups. The incidence of BPP in Sweden increased significantly from 1.4 per mill in 1980 to 2.3 per mill in 1994. The incidence was 45 times higher at a birthweight of > 4500 g than at a birthweight of < 3500 g. Fifty percent had a birthweight exceeding the mean +2 SD. In the Skaraborg series, half the children had normalized arm-hand function after 6 months (mean) and half had stationary impairment from 15 months (mean). Twenty-two percent of the children had severe stationary impairment of arm-hand function according to the criteria. There was no correlation between birthweight and the level of impairment. One-third of the newborn infants with BPP had neonatal care related to the difficult birth process and perinatal distress. The mothers of the children recalled the birth process as being difficult or very difficult in 77% compared with 20 and 27%, respectively, in the two control groups. This population-based investigation has revealed an unexpected increase in BPP in Sweden and has confirmed that BPP continues to be a significant cause of motor handicap in children.