Nature of the inhibitory effect of complex saccharide moieties on the tight binding of human spermatozoa to the human zona pellucida**This work was supported by the Contraceptive Research and Development Program (CONRAD), Eastern Virginia Medical School, under a cooperative agreement with the United States Agency for International Development (AID) (DPE 2044-AA-00-6063-00). The views expressed by the authors do not necessarily reflect the views of AID. Support was also provided by the Eastern Virginia Medical School Institutional grant 894A (GFC).††Presented in part at the 34th Annual Meeting of the Society for Gynecologic Investigation, St. Louis, Missouri, March 21 to 24, 1990.