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Updated: May 19, 2026

Development of a Neonatal Rat Model for Brachial Plexus Birth Injury
Published on: March 27, 2026
Severe brachial plexus palsy in women without shoulder dystocia
Manijeh Torki1, Lorayne Barton, David A Miller
1Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Objective:
Neonatal brachial plexus palsy frequently is described in conjunction with shoulder dystocia complicating a vaginal delivery. In this study, we present a series of cases of severe brachial plexus palsy that occurred without shoulder dystocia.
Methods:
Cases were identified from deliveries at the Los Angeles County and University of Southern California Medical Center. Various maternal and neonatal characteristics were analyzed.
Results:
Eight cases without shoulder dystocia but with severe brachial plexus palsy requiring neonatal intensive care unit admission were identified. None of the patients had maternal diabetes, previous shoulder dystocia, previous macrosomia, or labor induction. The mean second stage of labor was normal (2.15 ± 1.93), as was the mean birth weight (3,514 ± 1,043). One case required cesarean delivery.
Conclusion:
These results demonstrate that severe brachial plexus palsy occurs in women without shoulder dystocia and without identifiable risk factors.
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