Effect of oral contraceptive pills on rheumatoid arthritis disease activity in women: A randomized clinical trial

Background: Rheumatoid arthritis is one of the most common autoimmune diseases. Because immunological changes can be induced by steroid hormones, it seems that oral contraceptive pills can affect the severity of the disease. In this study, we examined the effect of oral contraceptive pills on rheumatoid arthritis activity in women. Methods: This blinded randomized clinical control trial was performed in the selected rheumatology centers in Tehran, Iran, in 2011. A total of 100 women with rheumatoid arthritis were included (50 in the intervention and 50 in the control groups), and those in the intervention group took oral contraceptive pills intermittently for 8 weeks. Disease activity was measured at 1 and 9 weeks based on DAS-28, which includes the number of tender joints, number of swollen joints, ESR, and GH. Data were analyzed using SPSS-16, and significance level was set at p≤0.05. This study was registered in IRCT (number: 138904224364N1) and all interventions were done after receiving confirmation from the Ethical Committee of Tehran University of Medical Sciences (Code: 250/ 6441). Results: After administering oral contraceptive pills to the intervention group, we found significant differences between the 2 groups in disease activity and severity scores (p=0.04). Intervention group showed lower swollen joints score (p=0.02), lower joint tenderness score (p=0.02), and lower general health score (p=0.001) than the control group. Conclusion: According to the results of this study, oral contraceptive pills can improve rheumatoid arthritis activity and severity. As these pills are used for contraception, women with rheumatoid arthritis can benefit from both effects of these pills.