Can post-thaw motility vary with the laboratory performing the analysis?
Yes, this is a valid concern. Post-thaw motility may vary depending upon: • The method of analysis • The time and temperature of incubation • The extender used for dilution Method of Analysis: At SBS we test post-thaw motility objectively by computer assisted sperm analysis (CASA). Clinicians without a CASA system determine motility visually by looking down the microscope and estimating the percent motility; this method is subject to observer bias and shows poor consistency of application and accuracy between technicians. However, there are still opportunities for the user to introduce bias into a CASA analysis; these include field selection and definition of the CASA settings. In our CASA system, a progressively motile sperm is defined as one that has an average path velocity (VAP) of > 50 microns/second AND is moving with a straightness value (STR) of > 75%. Since the thresholds for Progressive Motility can be set by the user it is important to understand that the clinician can incre
