Autoantibodies and pregnancy history in a healthy population

Our purpose was to determine whether the presence of autoantibodies is associated with pregnancy history in healthy adults.

Antibodies against phospholipid, histone, and nucleotide antigens were determined in 102 male and 99 female subjects. The effects of age, sex, marital status, and pregnancy history on antibody positivity were assessed.

Women showed higher levels of autoantibodies, but differences were not statistically significant in this sample. Age was not associated with antibody positivity in men. In women age was 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 prevalence of immunoglobulin G antibodies was increased in married women, although differences did not reach statistical significance (p = 0.167). Gravidity 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.

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 immunoglobulin G autoantibodies is associated with marriage, as a result of either exposure to semen or trophoblast antigens.