Presence of autoantibodies in women with unexplained infertility.

Serum samples from 41 patients suffering from unexplained infertility and 351 normal pregnant women were assayed for a range of autoantibodies by means of immunofluorescence, counterimmunoelectrophoresis, double immunodiffusion, Western blots, and enzyme-linked immunosorbent assays. The prevalence of autoantibodies to smooth muscle, phospholipid, and nuclear antigens, the latter when detected by immunofluorescence, was elevated in women with infertility compared with normal pregnant women (p less than 0.001, less than 0.001, and less than 0.05, respectively). Antiviral antibodies were not detected. The reason for the high level of autoreactivity in infertile women is unclear, but smooth muscle and antiphospholipid antibodies may actively interfere with the reproductive process.