Spermagglutinating antibodies and beta-spermagglutinins in sera from infertile and fertile women.

Sera from five groups of women were investigated by the tray agglutination technique for the presence of spermagglutinins: (1) 326 women from infertile couples, (2) 51 women in early pregnancy, (3) 65 women in advanced pregnancy, (4) 41 oral contraceptive users, and (5) 109 presumably fertile, nonpregnant women. By absorbing spermagglutinating sera with a cell-free eluate from spermatozoa, agglutination disappeared when due to a high-molecular weight compound with beta-mobility in preparative zone electrophoresis (denoted beta-spermagglutinin), whereas activity due to sperm antibodies was unchanged. Spermagglutinating sera occurred with comparable frequency among women from infertile couples, women in advanced pregnancy, and oral contraceptive users. The absorption study revealed agglutinating antibodies in a significantly higher frequency and in higher titers among women of infertile couples than among fertile women, in whom beta-spermagglutinins were found almost exclusively. These results demonstrate the importance of discriminating between sperm antibodies and beta-spermagglutinins in studies of sperm antibodies as a cause of infertility in women.