In accord with the present invention, the fertility quality of an ejaculate can be determined by assaying sperm, in aliquots of the ejaculate or of an ejaculate produced previously by the same male, at intervals over a period of time. Fertility quality is determined by the number of times the level of expression of a marker on the sperm goes through a maximum level of expression during the period of time and if desired by sperm state and fertilization procedure used. The marker should be capable of correlation with the level of Fc receptor (FcR) expression on the sperm. The fertility quality of the ejaculate is related to the number of times a maximum level of expression is reached.