Safety of Thiopurines and Anti-TNF-α Drugs During Pregnancy in Patients With Inflammatory Bowel Disease

OBJECTIVES: The safety of thiopurines and anti-tumor necrosis factor-alpha (TNF-alpha) drugs during pregnancy remains controversial, as the experience with these drugs in this situation is limited. Our aim is to assess the safety of thiopurines and anti-TNF-alpha drugs for the treatment of inflammatory bowel disease (IBD) during pregnancy. METHODS: Retrospective, multicenter study in IBD patients. Pregnancies were classified according to the therapeutic regimens during pregnancy or during the 3 months before the conception: non-exposed group, pregnancies exposed to thiopurines alone (group A), and pregnancies exposed to anti-TNF-alpha drugs (group B). An unfavorable Global Pregnancy Outcome (GPO) was considered if pregnancy developed with obstetric complications in the mother and in the newborn. RESULTS: A total of 187 pregnancies in the group A, 66 pregnancies in the group B, and 318 pregnancies in the non-exposed group were included. The rate of unfavorable GPO was different among the three groups (31.8% in non-exposed group, 21.9% in group A, and 34.8% in group B), being lower in pregnancies under thiopurines than among non-exposed (P=0.01). The rate of pregnancy complications was similar among the three groups (27.7% in non-exposed, 20.9% in group A, and 30.3% in group B). The rate of neonatal complications was different among the three groups (23.3% in non-exposed group, 13.9% in group A, and 21.2% in group B), being lower in pregnancies under thiopurines than among non-exposed (P=0.01). In the multivariate analysis, the treatment with thiopurines (odds ratio=0.6; 95% confidence interval=0.4-0.9, P=0.02) was the only predictor of favorable GPO, whereas maternal age >35 years at conception was the only predictor of unfavorable GPO. The treatment with anti-TNF-alpha drugs was not associated with an unfavorable GPO. CONCLUSION: The treatment with thiopurines and anti-TNF-alpha drugs does not seem to increase the risk of complications during pregnancy and does seem to be safe for the newborn. Am J Gastroenterol 2013;108:433-440; doi:10.1038/ajg.2012.430; published online 15 January 2013