AUTOANTIBODIES AND PREGNANCY HISTORY IN A HEALTHY POPULATION

OBJECTIVE: Our purpose was to determine whether the presence of autoan tibodies is associated with pregnancy history in healthy adults. STUDY DESIGN: Antibodies against phospholipid, histone, and nucleotide anti gens were determined in 102 male and 99 female subjects. The effects o f age, sex, marital status, and pregnancy history on antibody positivi ty were assessed. RESULTS: Women showed higher levels of autoantibodie s, but differences were not statistically significant in this sample. Age was not associated with antibody positivity in men. In women age w as associated with positivity for (1) immunoglobulin G antibodies (p = 0.009), (2) antihistone antibodies (p = 0.024), and (3) more than one antibody (p = 0.020). Immunoglobulin M antibodies were more common in unmarried than married females (p = 0.020). In contrast, the prevalen ce of immunoglobulin G antibodies was increased in married women, alth ough differences did not reach statistical significance (p = 0.167). G ravidity and history of fetal loss were not associated with increased antibody positivity. In subjects in whom follow-up data were available , positive antibody titers were not associated with subsequent adverse pregnancy outcome. CONCLUSIONS: In this population autoantibodies are not associated with adverse pregnancy outcome. However, an increased prevalence of immunoglobulin M in unmarried women and immunoglobulin G in married women suggests that a switch from immunoglobulin M to immu noglobulin G autoantibodies is associated with marriage, as a result o f either exposure to semen or trophoblast antigens.