Risk factors for neonatal brachial plexus palsy attributed to anatomy, physiology, and evolution.

Area of Science:

• Obstetrics
• Neonatal Medicine
• Anatomy

Background:

• Neonatal brachial plexus palsy (NBPP) is a known birth complication.
• Risk factors include infant anatomy and maternal pelvic structure, influenced by bipedalism.
• Current liability assessments for NBPP primarily focus on lateral neck traction during delivery.

Purpose of the Study:

• To highlight the role of neonatal and maternal anatomy in NBPP risk.
• To advocate for a broader consideration of risk factors in NBPP liability cases.
• To suggest including inherent anatomical predispositions in legal evaluations of NBPP.

Main Methods:

• Review of anatomical and physiological factors contributing to NBPP.
• Analysis of the biomechanics of fetal descent through the maternal pelvis.
• Examination of current legal standards for NBPP liability.

Main Results:

• Neonatal anatomy, such as prefixed brachial plexus and high head-to-body ratio, increases susceptibility to injury.
• The maternal birth canal's shape, adapted for bipedalism, presents unique delivery challenges.
• Infant anatomy and maternal pelvic structure are significant, yet often overlooked, contributors to NBPP.

Conclusions:

• Neonatal and maternal anatomical factors are crucial, controllable risk factors for NBPP.
• Liability assessments for NBPP should incorporate these inherent anatomical variables.
• A comprehensive approach considering fetal and maternal anatomy alongside delivery mechanics is essential for fair NBPP liability evaluation.