risk factors of rheumatoid arthritis development among females in north-west of iran: a case-control study

conclusions the risk of ra increased with delayed menarche, advanced maternal age at first delivery and early age at menopause. however, longer duration of breast-feeding, parity, large number of children and consumption of ocs were found as protective independent variables against ra. methods this case-control study was conducted on 231 patients with ra and 238 controls among females aged 26 - 64 years old from the north-west of iran. the adjusted risk of ra was assessed using multivariate logistic regression models. results females ≥ 14 years old at menarche, were more likely to be at risk of ra (or = 1.69; 95%ci: 1.08 - 2.64). advanced maternal age at first delivery (or = 1.91; 95%ci: 1.21 - 3.26) and having abortion (or = 1.97; 95%ci: 1.23 - 2.99) significantly increased the risk of ra. post-menopausal status increased the risk of developing ra (or = 2.97; 95%ci: 1.98 - 4.46). longer duration of breast-feeding was determined as significant protective variable for ra (p < 0.05). subjects with oral contraceptives (ocs) use (or = 0.36; 95% ci: 0.20 - 0.64), parity (or = 0.20; 95%ci: 0.06 - 0.70) or large number of children tended to show rather more reduced risk of ra. background given the high prevalence of rheumatoid arthritis (ra) in females of reproductive ages, it seems that hormonal factors might be important in ra pathogenesis. objectives the current study aimed to investigate the association between females’ reproductive factors occurring prior to the onset of rheumatoid arthritis and the risk of ra development.