Semen treatment with progesterone and/or acetyl-L-carnitine does not improve sperm motility or membrane damage after cryopreservation-thawing

Objective: To assess the effects of progesterone and acetyl-L-carnitine used before semen cryopreservation-thawing on sperm motility parameters and plasma membrane integrity. Design: Prospective cohort study. Setting: Academic tertiary center. Patient(s): Subfertile men undergoing semen evaluation. Intervention(s): Before cryopreservation, spermatozoa were incubated with water-soluble progesterone (1 and 10 μM), acetyl-L-carnitine (2.5, 5, 10, and 20 mM), or both (progesterone, 1 μM; and acetyl-L-carnitine, 5 mM). Main Outcome Measure(s): Postthaw change of motility parameters (computer-assisted measurements) and vitality-membrane integrity (examined with eosin-Y staining and annexin V-Cy3 binding assay). Result(s): There were no statistically significant differences between control samples and samples treated with progesterone and/or acetyl-L-carnitine for cryosurvival rate, motility parameters, or membrane integrity. The percentages of postthaw cells identified as live showed significantly different results with use of the eosin-Y staining and annexin V binding assay. Conclusion(s): Neither progesterone nor acetyl-L-carnitine seemed to prevent cryodamage assessed by motility changes or membrane integrity in human spermatozoa of subfertile men. Annexin V binding, a reflection of membrane translocation of phosphatidylserine, provided more distinct information about postfreezing membrane integrity changes than eosin-Y staining.