Rheumatoid arthritis (RA) itself doesn't seem to harm the developing baby, even if RA is active during pregnancy. In fact, 70% to 80% of women with RA have improvement of their symptoms during pregnancy. Although some women with RA may have a slight risk of miscarriage or low-birth-weight babies, most women have normal pregnancies without complications. However, many drugs for rheumatoid arthritis -- including methotrexate (Otrexup, Rheumatrex, Trexall) and leflunomide (Arava) -- can cause birth defects. These same medications may also cause birth defects if they are taken by men who father children. Therefore, it's important to talk to your doctor about altering treatment several months before you or your spouse try to get pregnant.