Immunologic disturbances must be considered a major cause of unexplained infertility. To evaluate the influence of sperm antibodies (SPAB) and zona pellucida antibodies (ZPAB) on the pregnancy rate, we have screened patients treated by in-vitro fertilization (IVF) and embryo transfer (ET) in the Department of Obstetrics and Gynecology of the School of Medicine, Hannover, for the presence of sperm antibodies and zona pellucida antibodies in the serum, cervical mucus and uterine secretions, and also in the serum and ejaculate of the husbands. After embryo transfer the concentrations of progesterone and beta-hCG in the sera were determined to evaluate the luteal phase and to detect early pregnancy. Among 122 women 11 clinical pregnancies were achieved; 8 of these pregnant women showed negative antibody reactions, while only 3 women with significant positive reactions for SPAB or ZPAB became pregnant. Only one pregnancy occurred in 24 women with high ZPAB titers. In conclusion, determinations of SPAB- and ZPAB-titers in serum and genital secretions are highly recommended in the evaluation of infertile couples.
