How to manage pruritus at 38 weeks of gestation?

Management of Excessive Itching at 38 Weeks of Gestation

Ursodeoxycholic acid (UDCA) at a dose of 10-15 mg/kg per day is the first-line treatment for pruritus at 38 weeks of gestation, particularly if intrahepatic cholestasis of pregnancy (ICP) is suspected or confirmed. 1

Diagnostic Approach

When a pregnant woman at 38 weeks presents with excessive itching, a systematic approach is needed:

1. Laboratory testing:

   • Serum bile acid levels (most sensitive indicator for ICP)
   • Liver function tests (ALT, AST, bilirubin, GGT)
   • If bile acids are normal but symptoms persist, repeat testing in 1-2 weeks 2

2. Physical examination:

   • Distribution of pruritus (palms and soles involvement suggests ICP)
   • Presence or absence of rash (ICP typically has no primary rash)
   • Evidence of excoriations from scratching 2

Treatment Algorithm

First-line treatment:

• UDCA (10-15 mg/kg/day) divided into 2-3 daily doses (typical regimens: 300 mg twice or three times daily, or 500 mg twice daily) 1
• Improvement in pruritus typically occurs within 1-2 weeks
• If pruritus is not relieved, dose can be titrated up to 21-25 mg/kg/day 1

For refractory symptoms:

1. Alternative or add-on medications:

   • S-adenosyl-L-methionine (may have additive effect with UDCA) 1
   • Rifampicin (can be combined with UDCA for refractory cases) 1
   • Cholestyramine (binds bile acids in gut but has significant side effects) 1
   • Caution: Monitor prothrombin time if using cholestyramine as it may exacerbate vitamin K deficiency in cholestasis 1

2. Symptomatic relief:

   • Antihistamines (diphenhydramine, hydroxyzine) - limited benefit but may help with sleep 1
   • Topical emollients - limited efficacy but safe 1
   • Cool compresses and oatmeal baths 2
   • Mild soaps and lukewarm water for bathing 2

Fetal Monitoring and Delivery Planning

At 38 weeks with pruritus, especially if ICP is suspected:

• Begin antenatal fetal surveillance immediately 1
• Consider delivery at 38 weeks of gestation to prevent stillbirth beyond that gestation 1
• Risk stratification based on bile acid levels:
  • <40 μmol/L: lower risk
  • 40-99 μmol/L: moderate risk (0.3% IUFD risk)
  • ≥100 μmol/L: high risk (3.4% IUFD risk) 2

Important Considerations

• Pruritus in ICP can precede the rise in serum bile acid levels by several weeks 1
• Some clinicians make the diagnosis of ICP based on clinical symptoms alone and start UDCA empirically 1
• If UDCA is started empirically before test results are available, elevated bile acid or transaminase levels may never be detected 1
• Persistent abnormalities after delivery should prompt evaluation for other chronic liver diseases 1

Common Pitfalls to Avoid

1. Misdiagnosis: Not all pruritus in pregnancy is ICP. Consider other pregnancy-specific dermatoses like polymorphic eruption of pregnancy, pemphigoid gestationis, or atopic eruption of pregnancy 3, 4

2. Inadequate monitoring: Failure to monitor for fetal complications in ICP can lead to adverse outcomes 1

3. Delayed treatment: Waiting for laboratory confirmation before starting treatment may prolong maternal discomfort 1

4. Insufficient dosing: Starting with too low a dose of UDCA or not titrating up when needed 1

5. Overlooking vitamin K deficiency: Cholestasis may lead to vitamin K deficiency and increased bleeding risk, especially if cholestyramine is used 1