Postpartum Neuropathy
From WikiMSK
Intrapartum injuries to the lumbosacral plexus generally involve the lumbar part of the plexus. This is due to its position above the pelvic brim rendering it susceptible to compression by the fetal head. Risk factors include short maternal stature and cephalopelvic disproportion.
| Nerve | Site of compression | Symptoms | Signs | Additional features |
|---|---|---|---|---|
| Lateral cutaneous nerve (L2-3) | Under the inguinal ligament or against the ASIS | Neuropathic pain or paraesthesia lateral thigh, often worse with standing or walking | sensory loss lateral thigh | Associated with prolonged hip flexion (lithotomy) |
| Femoral (L2-4) | Under the inguinal ligament or against the ASIS | Altered sensation in the femoral distribution, difficulty with climbing stairs | sensory loss in nerve distribution, knee extension weakness, decreased patellar reflex | Associated with prolonged hip flexion, bilateral in 25%. |
| Obturator (L2-4) | Lateral wall of lesser pelvis | Groin pain and difficulty walking | Sensory loss inner thigh, weakness of hip adduction and internal rotation | bilateral in 25%, commonly associated with femoral nerve injury |
| Lumbosacral plexus (L4-S3) | Posterior pelvic brim against the sacral ala | Abnormal sensation in the lumbosacral distribution. Tripping due to foot drop | Sensory loss lateral aspect of the leg and dorsum of the foot, weakness of dorsiflexion and eversion | Usually unilateral |
| Lumbosacral trunk / furcal nerve (L4-5) part of the lumbosacral plexus[1] | Compression from fetal head on pelvic brim | Tripping due to foot drop | Sensory loss foot and lateral aspect of the leg. Weak dorsiflexion, eversion, and inversion. | Usually unilateral. Associated with arrested labour. |
| Common peroneal (L4-5, S1-2) | Head of fibula | Tripping due to foot drop | Sensory loss in nerve distribution, weakness of dorsiflexion and eversion | Associated with poor lithotomy positioning |
