Paternal Exposure to Methotrexate and Pregnancy Outcomes

Objective. To assess the risk of major malformation in the case of paternal exposure to methotrexate (MTX) at the time of conception. Methods. Using prospective data of our Teratology Information Service, we analyzed outcomes of paternal MTX exposure at the time of conception or up to 3 months before conception. Results. We report on the outcomes of 42 pregnancies involving 40 men treated with MTX at the time of conception. Twenty-three men were treated for an inflammatory disease (54.8%), 9 for psoriasis (21.4%), and 8 for a malignant disease (19.0%). Weekly dosages varied between 7.5 mg and 30 mg. The pregnancies resulted in 36 live births, 3 spontaneous abortions, and 3 voluntary abortions. No congenital malformation was observed at birth. Conclusion. Based on our results and case reports in literature, paternal MTX exposure at the time of conception does not seem to raise any major concern for offspring. (First Release Jan 15 2011; J Rheumatol 2011;38:628-32; doi:10.3899/jrheum.100600)