Etiological risk factors for brachial plexus palsy.

OBJECTIVE

To investigate risk factors for brachial plexus palsy in newborns. We analyzed 45 544 live-born children, born over a nine-year period from January 1, 1996 to December 31, 2004.

METHODS

The analysis was retrospective and based on the medical documentation of the Clinic for Gynecology and Obstetrics, Clinic for Neurology, and Clinic for Physical Medicine and Rehabilitation of the University Clinical Center Tuzla. We compared study and control groups of newborns. Rates among groups were compared using Chi-square, with significance at p < 0.05, and with significance at p < 0.01.

RESULTS

Examining epidemiological characteristics, 86 newborns with brachial plexus palsy had been recorded, thus, the prevalence was 1.86 per 1000 live-born children. Analyzing maternal and neonatal factors, and the labor pattern itself, it was found that the highest factors of risk for brachial plexus injury were birth weight of over 4000 g, a precipitous second stage of labor (<15 minutes), and vacuum-extractor assisted labor. Brachial plexus palsy was more frequent when the mothers were overweight, with a body mass index >or=29 kg/m2. None of the parturient women, whose newborns were diagnosed with brachial plexus palsy, had external conjugate diameter <18 cm. Newborns delivered vaginally were not diagnosed with a higher frequency of brachial plexus palsy when compared to newborns who were delivered by cesarean section, but newborns who were vaginal breech-delivered were diagnosed to have a higher incidence of brachial plexus palsy. Newborns whose mothers were older than 35 years were diagnosed to have brachial plexus palsy more frequently, but a statistically significant difference between primiparas and multiparas was not found. A total of 39 newborns (45.2%) were diagnosed with a fracture of the clavicle, which was the most frequently combined damage with brachial plexus injury. Forty-two newborns (48.8%) had an Apgar score of