Do breast‐feeding and other reproductive factors influence future risk of rheumatoid arthritis?: Results from the Nurses' Health Study

Abstract

In this large cohort, breast-feeding for >12 months was inversely related to the development of RA. This apparent effect was dose-dependent, with a significant trend toward lower risk with longer duration of breast-feeding. Irregular menstrual cycles and earlier age at menarche increased the risk of RA. Other reproductive hormonal factors were not associated with RA risk.