In vitro evaluation of sperm quality

This paper highlights selected laboratory analyses that are currently used to evaluate sperm, and describes why results from these assays do not consistently correlate with sperm fertility. Reasons for the disconnect between the two are due in part to the definition and reliability of the fertility data collected, to the complexity of the spermatozoon itself, to imprecision of some measurements, and. to uncontrollable factors not associated to either the laboratory analysis or the sperm sample. Each sperm must possess a number of different attributes to fertilize an oocyte, and individual laboratory assays measure only one or a few of these attributes. Current and past data, correlating laboratory assay data with sperm fertility are presented in an effort to determine which types of assays are important to conduct and when to conduct them. Even though laboratory assay results do not allow accurate evaluation of the fertilizing potential of a semen sample, these assays are important to enable culling of poor quality samples. (C) 2007 Elsevier B.V. All rights reserved.