The prognostic value of antinuclear antibodies in women with recurrent pregnancy losses: a prospective controlled study.

Because autoimmune diseases are suspected of causing some cases of recurrent pregnancy loss, we sought clinical and serologic evidence of such diseases in a group of 277 women with recurrent pregnancy loss. Using HEp-2 cells as targets for an indirect immunofluorescence test for antinuclear antibodies, we compared the frequency of a positive antinuclear antibody test in the women with recurrent pregnancy loss to that in 299 pregnant controls and 119 nonpregnant controls. The frequency of positive antinuclear antibody tests at a titer of 1:40 or higher was 16.3% in cases, 16.6% in pregnant controls, and 16.8% in nonpregnant controls. Increasing the critical titer to 1:80, however, led to a statistically significant difference between cases (6.9%) and controls (0 and 0.8%, pregnant and nonpregnant, respectively; P less than .0001). Additional serologic tests failed to identify any subclinical autoimmune diseases, although two antinuclear antibody-negative patients later developed systemic lupus erythematosus. Pregnancy outcome in women with antinuclear antibody titers of 1:80 or higher included 52% live births, compared with 65.6% live births in women with three or more pregnancy losses and an entirely normal comprehensive evaluation, a nonsignificant difference. The combination of clinical evaluation and antinuclear antibody tests did not identify new cases of autoimmune disease in this population.