Anti-Sperm Antibodies

What exactly are anti-sperm antibodies? Is this a female problem, a male problem, or both? Kathy

Anti-sperm antibodies can occur in both men and women. Antibodies are protein molecules that are attracted to a specific site on the sperm. Once attached, they may interfere with the sperm's activity in any of several ways. They may immobilize sperm, cause them to clump together, limit their ability to pass through the cervical mucus, or prevent them from binding to and penetrating the egg. Anti-sperm antibodies are frequently seen in men after vasectomy, testicular injury or infection. The cause of anti-sperm antibodies in the woman is unknown.

Researchers classify specific antibodies by type (IgA, IgG and IgM) as well as the point at which they attach to the sperm (head, midpiece, or tail). Studies indicate that IgG type antibodies are most common in men and that IgA type can be found in women's mucus and follicular fluid, but the significance of these findings is uncertain. Binding to the head is believed to interfere with attachment and penetration of the egg, while tail binding interferes with motility.

Unfortunately, testing and identification of type of antibody or the location does little to suggest who will or won't conceive. Attempts to treat the condition -- say, by lowering antibody levels with steroids or removing the antibodies from sperm -- have demonstrated limited benefit and have been fraught with disastrous complications. A trial of ovulation induction and insemination followed by in vitro fertilization with ICSI (a process that involves injecting a sperm directly into an egg) seems to be the best treatment available.