Association between failure to impregnate after vasovasostomy and sperm agglutinins in semen.

Sperm agglutinins emerging from the reopened part of the vas deferens were found in the seminal fluid of 10 out of 29 men after vasovasostomy. There was a strong association between the presence of these antibodies and the failure to impregnate over a period of 14 to 33 months. Of 20 couples, 11 pregnancies resulted among the 13 women whose men had no sperm agglutinins in the seminal fluid, but only 1 among the 7 whose men had such antibodies, 2p = 0.0044. The presence of sperm agglutinins in the seminal fluid was always associated with their presence in the serum, usually in a higher titre. Preoperative serum levels thus are highly predictive of ability to impregnate after reversal of vasectomy.