What is the approach to bilateral arm numbness during pregnancy?

Approach to Bilateral Arm Numbness in Pregnancy

Bilateral arm numbness in pregnancy is most commonly carpal tunnel syndrome (CTS), which should be diagnosed clinically and managed with wrist splinting in a neutral position as first-line treatment. 1

Clinical Diagnosis

Carpal tunnel syndrome is the most likely diagnosis when pregnant women present with bilateral arm numbness, occurring in 17-62% of pregnancies. 2, 3 The condition is caused by fluid retention and increased joint laxity, particularly in late pregnancy. 1

Key Clinical Features to Assess:

• Distribution of symptoms: Numbness and tingling should involve the thumb, index finger, middle finger, and radial half of the ring finger (median nerve distribution). 2
• Associated symptoms: Burning dysesthetic wrist pain, loss of grip strength and dexterity, and symptoms that worsen at night or with forceful activity. 2
• Proximal radiation: Pain may radiate along the volar forearm, medial arm, and shoulder, though this is less common. 2
• Timing: Symptoms most commonly present in the third trimester (50-63% of cases), though onset can occur in any trimester. 3, 4

Physical Examination:

• Tinel sign: Present over the median nerve at the wrist in 95% of cases. 4
• Phalen test: Useful provocative maneuver, though clinical signs have only 52% sensitivity and 23% specificity compared to electrodiagnostic studies. 3

Diagnostic Testing

Clinical diagnosis based on history and physical examination is sufficient to initiate treatment in most cases. 2 However, important caveats exist:

• 42% of pregnant women with CTS may be asymptomatic on electrodiagnostic testing, and clinical examination cannot diagnose all cases. 3
• Electrodiagnostic studies are more reliable than clinical signs alone and may be considered in the third trimester if diagnosis is uncertain or symptoms are severe. 3, 5
• Median nerve function is impaired in virtually all pregnant women during the third trimester, even without symptoms. 2

Treatment Algorithm

First-Line Conservative Management:

Wrist splinting in a neutral position is the recommended first-line treatment, providing superior symptom relief compared to other conservative options. 1 This approach is most effective in patients with minimal to moderate lesions and shorter symptom duration. 1

Additional Conservative Measures:

• Activity modification to avoid forceful activities and extreme wrist positions. 2
• Edema control measures. 2
• Physical therapy may be considered as part of conservative management. 6

Second-Line Treatment:

• Steroid and lidocaine injections can be considered if splinting fails to provide adequate relief. 2, 7
• Of treated patients with available follow-up data, 25 of 26 improved with conservative treatment (splinting, injections, or both). 4

Surgical Intervention:

• Surgery should be avoided during pregnancy unless absolutely necessary. 1
• Only 4 of 26 conservatively treated patients required surgery in one study, and all 7 women who underwent surgery had complete symptom resolution. 4
• Surgery can be considered postpartum if conservative treatment fails. 4

Prognosis and Follow-Up

• Most pregnancy-related CTS resolves spontaneously after delivery due to resolution of fluid retention. 1
• However, a significant percentage of women may continue to have symptoms up to 3 years postpartum and may need to continue wearing splints. 2
• Maintain high vigilance in managing these patients given the potential for persistent symptoms. 2

Important Clinical Pitfalls

• Do not rely solely on clinical examination: Sensitivity and specificity of clinical signs are much lower than electrodiagnostic testing, and many cases may be missed. 3
• Bilateral involvement is common: 47.5-68% of cases are bilateral, so examine both hands even if symptoms are predominantly unilateral. 3, 4
• Severity increases with gestational age: The prevalence and severity increase as pregnancy progresses, with 63% of cases diagnosed in the third trimester. 3