Arthritis is a term that refers to inflammation (swelling, pain, and redness) in the joints. Rheumatoid arthritis (RA) is one type of arthritis that can sometimes affect other body systems. RA is the most common type of arthritis that is triggered by the immune system, although the exact cause or causes are not known. The severity of RA can vary from person to person. Many individuals with RA have ongoing milder symptoms with shorter periods of more severe symptoms (flares). RA can occur in both men and women, but it is more common in women.
In the United States, 1.4% of women (or 1 in 71) currently have RA, with most women experiencing their first symptoms in their 50s (Gabriel 1999). However, recent nationwide estimates suggest that about 1,000-2,000 women with RA become pregnant each year. Since most people with RA require medicine to control inflammation and prevent or reduce damage to the joints, a medicine discussion with your doctors is especially important for women with RA who are planning a pregnancy or have learned they are pregnant.
There have been suggestions that RA may reduce fertility, however, it is not known whether this is a direct result of RA or simply because women with RA have waited longer before attempting pregnancy or chosen to have smaller families (Katz 2006). Many women with RA will have some improvement in symptoms during pregnancy, but most will experience an increase in symptoms within four months of delivery. The majority of early studies of disease activity of RA during pregnancy found RA improved in at least 75% of women, although newer estimates are lower (deMan et al., 2008). Improvements are often seen as early as the first trimester of pregnancy and continue through the end of pregnancy. While this is encouraging, it still leaves at least 25% of women who will not improve during pregnancy. Doctors are not able to predict for any one woman whether her symptoms will improve, stay the same, or worsen during pregnancy.
There are limited studies on pregnancy outcomes of women with RA and the studies themselves are limited in that they cannot tease out what is due directly to RA, what is due to the severity of RA, or what is due to the medicines, or a combination of all these factors. RA during pregnancy does not appear to be associated with miscarriage but is associated with higher rates of pregnancy complications including premature delivery and C-sections (Reed 2006). Another study found that infants born to mothers with RA had slightly lower birth weights (although generally within the normal range), and that the lower birth weights were associated with increased disease activity of RA during pregnancy (deMan et al. 2009). Therefore, a discussion of medicine use during pregnancy should include not only any concerns with RA medicines on the pregnancy but include possible concerns with active disease on the pregnancy.
In summary, many but not all, women with rheumatoid arthritis can expect some degree of relief or reduction of symptoms during pregnancy. In general, maternal RA does not cause significant risks to the fetus, but newer data suggest that increased or uncontrolled disease activity during pregnancy may have subtle effects on fetal growth. If possible, pregnancy should be delayed until RA is under control. Some commonly used medications to control disease activity have potential for causing a risk to development of the baby and ideally should be stopped prior to pregnancy. Women with RA who are considering pregnancy or those who have an unplanned pregnancy should receive counseling regarding medication use in pregnancy. Ideally women with RA who wish to become pregnant should be switched to medications with fewer associated fetal risks for at least 3-6 months prior to becoming pregnant. Birth control should be used during times when women are taking medications that have higher fetal risks. Open discussions with health care providers should contribute to the best pregnancy outcomes in women with RA.
For information about participating in the OTIS Autoimmune Diseases and Pregnancy Study, please go to the Autoimmune Diseases Study Page. More information.
Dr. Eliza Chakravarty is an Assistant Professor of Medicine (Immunology & Rheumatology)
at the Stanford University Medical Center
de Man YA et al. (2008) Disease activity of rheumatoid arthritis during pregnancy: results from a nationwide prospective study. Arthritis Rheum 59(9)1241-8.
de Man YA et al.(2009) Association of higher rheumatoid arthritis disease activity during pregnancy with lower birth weight: results of a national prospective study.Arthritis Rheum 60(11):3196-206.
Katz PP (2006) Childbearing decisions and family size among women with rheumatoid arthritis. Arthritis Rheum 2006 Apr 15;55(2):217-23.
Reed SD, Vollan TA, Svec MA (2006) Pregnancy outcomes in women with rheumatoid arthritis in Washington State. Matern Child Health J 10(4):361-6.