Risk Factors at Birth for Permanent Obstetric Brachial Plexus Injury and Associated Osseous Deformities

Abstract

Purpose. To examine the most prevalent risk factors found in patients with permanent obstetric brachial plexus injury (OBPI) to identify better predictors of injury. Methods. A population-based study was performed on 241 OBPI patients who underwent surgical treatment at the Texas Nerve and Paralysis Institute. Results. Shoulder dystocia (97%) was the most prevalent risk factor. We found that 80% of the patients in this study were not macrosomic, and 43% weighed less than 4000 g at birth. The rate of instrument use was 41% , which is 4-fold higher than the 10% predicted for all vaginal deliveries in the United States. Posterior subluxation and glenoid version measurements in children with no finger movement at birth indicated a less severe shoulder deformity in comparison with those with finger movement. Conclusions. The average birth weight in this study was indistinguishable from the average birth weight reported for all brachial plexus injuries. Higher birth weight does not, therefore, affect the prognosis of brachial plexus injury. We found forceps/vacuum delivery to be an independent risk factor for OBPI, regardless of birth weight. Permanently injured patients with finger movement at birth develop more severe bony deformities of the shoulder than patients without finger movement.

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“…The most common and significant association of NBPP reported in the literature is SD, with which NBPP occurs in 50% of such cases. 1 SD had previously been shown to occur in nearly all permanent NBPP examined, 8,9 though recent evidence has shown this may not be the case. 6,10 As seen in our results, SD was not significantly different between nulliparous and parous women in this cohort, and thus should not be considered a confounding factor when evaluating the role of parity in permanent NBPP.…”

“…1 Nath et al reported that in 239 permanent NBPP patients 41% were delivered via instrumental delivery. 8 Another study reported 21% of 63 permanent NBPP had an operative delivery. 9 Although operative vaginal delivery occurred more often in nulliparous women compared with parous women in this study (31 and 17%, respectively), there was no significant difference in the persistence of NBPP at 1 and 2 years between the two groups.…”

Surgical Management of Obstetric Brachial Plexus Palsy Secondary Deformities

“…Shoulder dystocia is, therefore, closely associated with the most severe cases of permanent obstetric brachial plexus injuries [8,9,11]. However, permanent injury is not exclusive to large infants; 80% of the OBPI patients in our published study were not macrosomic and 43% (104/241) weighed less than 4000 g at birth [14]. OBPI that occur during breech deliveries may have a different mechanism of onset, and are more likely to be bilateral.…”

“…Reported risk factors for OBPI include shoulder dystocia, macrosomia (defined as birth weight greater than 4500 g) [8][9][10][11]), instrument-assisted delivery, and downward traction of the fetal head [3,12,13]. Shoulder dystocia is the most prevalent risk factor in our patients [14]; almost all the children in our study had documented shoulder dystocia [14]. Shoulder dystocia is, therefore, closely associated with the most severe cases of permanent obstetric brachial plexus injuries [8,9,11].…”

Early electrodiagnosis in the management of neonatal brachial plexus palsy: A systematic review

“…Prevention is difficult due to the unpredictability and multifactorial nature of the risk factors. As severity varies from neurapraxia, axonotmesis, and neurotmesis, to root avulsion, and the extent of injury varies between damage to one nerve or all roots, the impact of neonatal plexopathy ranges from temporary functional impairment to a lifelong total paralysis of one arm …”