Understanding Shoulder Dystocia and Brachial Plexus Injury

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Understanding Shoulder Dystocia and Brachial
Plexus Injury
Jim Greenberg, MD, FACOG Department of
Ob/Gyn Brigham Womens Hospital
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Understanding Shoulder Dystocia and Brachial
Plexus Injury
Caveat This is a brief overview of the
topic. The data reported herein should be
considered reasonable literature-based estimates
rather than absolute numbers.
DO NOT QUOTE THESE STATISTICS
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Understanding Shoulder Dystocia and Brachial
Plexus Injury
Absolute Risk vs. Relative Risk
Causation vs. Malpractice
Risk Factors vs. Technique
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Understanding Shoulder Dystocia and Brachial
Plexus Injury
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Why do we care about brachial plexus injury?

• Permanent brachial plexus injury 1- 6.7 per
  10,000
• Doesnt sound too bad

400 - 2,680 injuries per year in the U.S.
(based on 4 million births)
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Understanding Shoulder Dystocia
Incidence of Shoulder Dystocia 0.2 to 3.0 of
all vaginal deliveries
Risk Factors for Shoulder Dystocia fetal
macrosomia (gt4,500) maternal diabetes abnormal
labor maternal weight operative vaginal
delivery prior shoulder dystocia
Only 25 of shoulder dystocias have at least 1
risk factor
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Anatomy
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Anatomy

• Erb-DuchennePalsy
• C5-C6 (80)
• Deltoid muscle
• Infraspinatus
• Biceps
• Klumpkes Palsy
• C7-T1

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Mathematical Modeling
Bernard Gonik, MD Robert Allen, PhD

• Contact Force at shoulder-symphysis interface
  highest with maternal pushing
• McRoberts positioning reduced contact force

Clinician-applied lateral traction Normal
Delivery 47 N Difficult Delivery 69
N Shoulder Dystocia 100 N
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Risk Factors for Permanent Brachial Plexus Injury

• Birth Weight gt4500 41
• Diabetes 11
• gt2 hr Second Stage 14
• Operative Vaginal Delivery 21
• Shoulder Dystocia 94
• Ouzounian, Korst, Phelan

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Maneuvers for ShoulderDystocia Alleviation

• McRoberts Maneuver
• 42 success alone (Gherman)
• Suprapubic pressure
• Woods Corkscrew (ant surface of post shoulder)
• Rubins Maneuver (post surface of either
  shoulder)
• Posterior arm extraction
• All Fours
• 52.4 success (Bruner)
• Zavanelli Maneuver

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Risk Factors vs. Math
There are no reliable ways to predict shoulder
dystocia and/or permanent brachial plexus injury
and therefore, repeated drills of maneuvers and
a plan are the best methods to minimize
injuries.
vs.
If there is a permanent brachial plexus injury,
the delivering provider MUST have applied
excessive force.