Is fluconazole (an antifungal medication) safe to use during pregnancy?

Fluconazole Safety During Pregnancy

Fluconazole should be avoided during pregnancy, especially in the first trimester, due to risks of birth defects and spontaneous abortion. 1, 2

Risks of Fluconazole in Pregnancy

First Trimester Concerns

• High-dose fluconazole (400-800 mg/day) has been associated with a distinct pattern of birth defects including:

  • Craniosynostosis
  • Abnormal facial development
  • Cleft palate
  • Femoral bowing
  • Thin ribs and long bones
  • Congenital heart disease 1, 2

• Even low-dose fluconazole (150 mg) during early pregnancy has been associated with:

  • Increased risk of spontaneous abortion (adjusted OR 2.23,95% CI 1.96-2.54) 3
  • Potential risk of congenital abnormalities 1

Later Pregnancy Risks

• High-dose fluconazole (>150 mg) during the first trimester is associated with increased risk of cardiac septal closure anomalies (adjusted OR 1.81,95% CI 1.04-3.14) 3
• Risk of tetralogy of Fallot may be increased (adjusted prevalence odds ratio 3.16,95% CI 1.49-6.71) 4

Treatment Algorithm for Fungal Infections During Pregnancy

For Vaginal Candidiasis

1. First-line treatment: Topical azole antifungals (clotrimazole, miconazole) 1

   • Minimal systemic absorption
   • Considered safe throughout pregnancy
   • Effective for most cases of vaginal candidiasis

2. For refractory cases:

   • Continue with extended course of topical azoles
   • Avoid oral fluconazole if possible, especially in first trimester

For Systemic Fungal Infections

1. First-line treatment: Amphotericin B formulations 5, 1

   • FDA category B for pregnancy
   • Well-distributed in umbilical cord serum, amniotic fluid, and placenta
   • No documented teratogenicity

2. Second/Third trimester options (if benefits outweigh risks):

   • Low-dose fluconazole may be considered after first trimester 5
   • Monitor closely for adverse effects

Special Considerations

Breastfeeding

• Fluconazole is present in breast milk at concentrations similar to plasma 1
• The American Academy of Pediatrics indicates breastfeeding while receiving fluconazole is likely safe for the newborn 5
• Other azole antifungals should be avoided during breastfeeding 5

Monitoring Recommendations

• For women with history of fungal infections who become pregnant:
  • Close follow-up with serologic testing at initial visit
  • Repeat testing every 6-12 weeks throughout pregnancy 5
• For women who require fluconazole during pregnancy:
  • Monitor for signs of fetal distress
  • Consider detailed ultrasound to evaluate for potential malformations

Common Pitfalls to Avoid

1. Prescribing fluconazole without confirming pregnancy status - Always verify pregnancy status before prescribing
2. Using high-dose fluconazole in early pregnancy - Even single doses carry risk
3. Failing to consider topical alternatives - Topical treatments should be first-line for vaginal infections
4. Not providing contraception counseling - Effective contraception should be recommended to women on fluconazole therapy 2

The evidence clearly shows that while fluconazole is commonly used for fungal infections, its use during pregnancy carries significant risks that outweigh benefits in most cases, particularly during the first trimester.