Immunologic reactions involving sperm cells and preimplantation embryos.

Evidence that sperm cells share or impart antigenic specificities to fertilized ova and cleaving embryos in animals was first demonstrated indirectly in female animals isoimmunized against sperm or testis cells. While early studies often gave conflicting results, postfertilization infertility effects were occasionally reported. The systematic analysis in animals of anti~ertility e~ects after immunization with sperm or testis preparations resulted in a clearer delineation of the affected stages and modes of action. In a study of the effects of antisperm antisera on the fertility of sperm in rabbits, Kiddy et al. reported t~~t a dilution of serum that permitted near-normal fertilization rates resulted in significantly lowered levels of embryo survival.f Isoimmunization offemale ani~alswi~h sperm or testis preparations has often produced mcon~Is­ tent results regarding the degree and stage at which infertility occurs; however, studies in which antifertility