Hyperactivated Motility of Human Spermatozoa During In Vitro Capacitation and Implications for Fertility

The acrosome reaction is no longer viewed as the sole phenomenon which signals the completion of capacitation. Increasingly, hyperactivated motility of spermatozoa has been included as a second functional marker. An understanding of the present data on human (HA) could impact substantially on any laboratory intending to assess human sperm capacitation. The divergent conclusions about human HA patterns can be appreciated by examining one group of recent studies which utilized slow-motion analysis in contrast to a second group of reports that relied on digital image analysis methods. An excellent study by Morales et al. utilized high-speed videomicrography and rigorous frame-by-frame analysis to examine alterations in human sperm motility during capacitation. The momentum of male infertility therapy may, in fact, lead to the development of two methodologies for assessing human HA: one that is streamlined for use in the average clinic and another for more rigorous research protocols.