A pair of twins born after maternal exposure to leflunomide.

Leflunomide is a drug used in rheumatoid arthritis with teratogenic and fetotoxic effects. Clinical data on human pregnancies are limited to a few case reports without detailed information whether the mothers did have a washout procedure as suggested by the manufacturer or what type of malformation the offspring showed. We report on a set of twins born after maternal exposure to leflunomide who had a largely normal neonatal outcome, providing information about the washout procedure and the blood level of the active metabolite.