What is the recommended medication for maintaining remission in women with Inflammatory Bowel Disease (IBD) who are planning pregnancy?

Thiopurines (Azathioprine/6-MP) Are Recommended for Maintaining IBD Remission During Pregnancy

For women with Inflammatory Bowel Disease (IBD) planning pregnancy, thiopurines (azathioprine or 6-mercaptopurine) should be continued throughout pregnancy to maintain remission, as the risks of active disease outweigh medication risks. 1

Evidence-Based Recommendations for IBD Medications During Pregnancy

First-Line Maintenance Therapy Options:

• Thiopurines (Azathioprine/6-MP):

  • Strong recommendation to continue throughout pregnancy 1
  • No association with major congenital anomalies 1
  • Safe use established in multiple studies 2, 3
  • Benefits of maintaining remission outweigh potential risks

• 5-ASA medications:

  • Safe during pregnancy (mesalamine, sulfasalazine) 1
  • For sulfasalazine: supplement with 1mg folic acid twice daily starting 3 months before conception 1
  • Consider switching from formulations containing dibutyl phthalate (DBP) to those without 1

• Anti-TNF biologics:

  • Safe to continue during pregnancy 1
  • May be continued as monotherapy or in combination with thiopurines based on individual disease characteristics 1

Medications to Avoid:

• Methotrexate: Absolutely contraindicated during pregnancy
  • Must be discontinued at least 3-6 months before conception 1
  • Teratogenic risk requires immediate discontinuation if pregnancy occurs 1

Clinical Considerations and Monitoring

Disease Activity Management:

• Active IBD during pregnancy poses greater risks than medication exposure:
  • Increased risk of preterm birth
  • Low birth weight
  • Spontaneous abortion
  • Poor maternal outcomes

Thiopurine-Specific Monitoring:

• Monitor for potential side effects:
  • Potential for neonatal anemia (reported in up to 60% of newborns) 1
  • Consider NUDT15 genotyping in both prospective parents to avoid adverse fetal outcomes 4
  • Monitor for intrahepatic cholestasis of pregnancy (ICP), which occurs at higher rates with thiopurine exposure (OR 6.65) 5

Delivery Considerations:

• Base delivery method on obstetric indications rather than IBD diagnosis alone 1
• Consider cesarean delivery for:
  • Active perianal Crohn's disease 1
  • Patients with ileal pouch-anal anastomosis (IPAA) 1
  • Complex fistulizing disease 1

Algorithm for Managing IBD Medications During Pregnancy Planning

1. Pre-conception planning:

   • Achieve disease remission before conception
   • Evaluate current medication regimen
   • Discontinue methotrexate at least 3-6 months before attempting conception
   • Continue thiopurines and/or biologics to maintain remission

2. During pregnancy:

   • Continue thiopurines throughout pregnancy
   • Monitor disease activity closely
   • Treat flares promptly with appropriate medications (corticosteroids or anti-TNF therapy if needed) 1
   • Monitor for potential complications (especially ICP with thiopurines)

3. Delivery planning:

   • Consult with high-risk obstetrics for complicated IBD
   • Plan delivery method based on disease characteristics and obstetric indications

The evidence strongly supports maintaining IBD remission during pregnancy with appropriate medications, as the risks of active disease far outweigh the potential risks of medication exposure.