Abstract: | A total of 14,856 women, including 921 pregnant subjects, were tested for rheumatoid factor; 4,562 were using oral contraceptives at the time of testing. The prevalence of rheumatoid factor increased directly with age. The age-adjusted prevalence of rheumatoid factor was lower in oral contraceptive users than in nonusers but this difference was not statistically significant. Rheumatoid factor remained positive in 39% of subjects undergoing retesting after an average interval of 16 months. Those women with higher titers of rheumatoid factor were more likely to remain positive (81%). Of the women having positive tests, 5.4% were identified as having rheumatoid disease. |