Women with rheumatoid arthritis who inadvertently became pregnant while taking leflunomide (Arava) were not at increased risk of giving birth to babies with major malformations, a prospective cohort study found.
Women exposed to the drug had a 5.4% rate of major structural defects, while a disease-matched comparison group and a healthy comparison group both had rates of 4.2%, according to Christina D. Chambers, PhD, of the University of California San Diego, and colleagues.
That was not a significant difference (P=0.13), and the rates in all three groups were similar to the 3% to 4% expected in the general population, the researchers reported online in Arthritis & Rheumatism.
Leflunomide is an isoxazole immunomodulatory agent shown in animal studies to be both embryotoxic and teratogenic, and thus has been classified as pregnancy category X.
A few case reports have been published of births after maternal exposure, but the data have been sparse and inadequate for the purpose of advising women who unexpectedly become pregnant.
http://www.medpagetoday.com/Rheumatology/Arthritis/18569