Ninety-six women with rheumatoid arthritis (RA) were found to have an abortion ratio higher than that of a comparison group (p = 0.005). This was true even before the onset of their RA (p = 0.007). The fertility rate of the patients with RA was not different from the control patients. This suggests the presence of a "rheumatoid diathesis" which long antedates the expression of the disease.