Multicentre study and systematic review: Allopurinol exposure during pregnancy

Area of Science:

• Reproductive medicine
• Pharmacology
• Gastroenterology

Background:

• Limited data exists on allopurinol safety during pregnancy.
• Investigating adverse pregnancy outcomes and congenital abnormalities following in utero allopurinol exposure is crucial, particularly for inflammatory bowel disease (IBD) patients.

Approach:

• Collected safety data from 42 IBD pregnancies treated with allopurinol and thiopurine concurrently.
• Conducted a systematic literature review on allopurinol's teratogenic potential, analyzing 102 additional pregnancies.

Key Points:

• In the IBD cohort, 14.3% experienced miscarriage, 1.6% had congenital anomalies, and 15.2% of neonates were small for gestational age.
• The systematic review of 129 live births revealed a 7.8% congenital anomaly rate.
• Sub-analysis of 76 IBD infants showed a 2.6% anomaly rate with low-dose allopurinol exposure.

Conclusions:

• The teratogenicity of allopurinol requires further investigation.
• Allopurinol/thiopurine co-therapy for IBD during pregnancy does not seem to elevate the risk of congenital anomalies.