BACKGROUND AND PURPOSE:

• Johnson et al. (Obstetrics & Gynecology, 2020) analyze the origins and consequences of cases of brachial plexus injuries and their relationship to shoulder dystocia

METHODS:

• Retrospective cohort study (2012 to 2019)
• Data extracted using ICD9 and ICD10 codes
  • All neonates with brachial plexus injury
  • All mothers with shoulder dystocia
• Study design
  • Extracted cases were reviewed by a physician author
  • Shoulder dystocia definition
    • “Shoulder dystocia or any difficulty in delivery” documented in the record
  • Delivering clinician experience also noted
• Brachial plexus injury stratified
  • Shoulder dystocia present vs not present
  • Injury transient vs persistent (present at discharge)
• Temporal trends were also investigated

RESULTS:

• 41,525 deliveries overall
  • Brachial plexus injury: 0.08% (33 cases)
• Of the cases of brachial plexus injury
  • 42% were not associated with shoulder dystocia
  • 9% followed cesarean
• Brachial plexus injury without shoulder dystocia was related to
  • Absence of maternal diabetes
  • Lower birth weights
  • A longer second stage of labor
• Persistent brachial plexus injury was present in cases with and without shoulder dystocia (P = 0.36)
  • With shoulder dystocia: 89%
  • Without shoulder dystocia: 71%
• Clinician experience was not associated with persistence of brachial plexus injury

CONCLUSION:

• The current study is consistent with previous reports of high frequency of brachial plexus injury that is not related to shoulder dystocia at the time of delivery
• The lack of relationship between clinician experience and outcomes may indicate that team training and simulation may help in some settings (e.g. high shoulder dystocia rates) but ultimately my not result in lowering injury rates beyond a certain threshold
• The authors suggest that based on the data in this study and previous literature

…both brachial plexus injury and shoulder dystocia often reflect two causally unrelated complications of uterine forces driving a fetus through the birth canal in the presence of disproportion between the passage and the shoulder girdle of the passenger

Learn More – Primary Sources:

Pathophysiologic Origins of Brachial Plexus Injury

Related ObG Topics:

Shoulder Dystocia: Diagnosis, Evaluation and Management

New Technique: Shoulder Shrug Maneuver for Delivery During Shoulder Dystocia

Does Pre-Pregnancy Obesity Increase Risk of Shoulder Dystocia?