A functional analysis and the potential clinical significance of 7 categories of sperm morphology

Sperm morphology is a critical factor in the evaluation of infertile men. Patients often exhibit a morphology profile with consistent increases of specific abnormal categories of sperm morphology. We analyzed the functional ability of 7 categories of sperm morphology using assays that measure sperm viability longevity, deoxyribonucleic acid packing, acrosomal status, and the stimulation of the acrosome reaction with human cumulus/oocyte complexes and calcium ionophore A23187. Each morphology category was separately analyzed initially and at 3, 6, 12, 18 and 24 hours of in vitro culture. The data indicate that all categories of abnormal sperm morphology exhibit various functional debilities. However, tapered sperm most closely approached normal sperm function. All abnormal categories possessed subpopulations of sperm that functioned normally to the limits of these assays. These data indicate that increases in any of the categories of abnormal sperm morphology may lead to decreased fertility due to diminished functional ability indicated by the assays performed in this study.