Effects of cryopreservation on the motility characteristics of human spermatozoa

Abstract

Ejaculates (164) were obtained from 17 donors serving on an artificial insemination by donor panel. Semen analysis was performed before and after freezing by an integrated microcomputerized system employing the multiple-exposure photography (MEP) method. Sperm count, motility, velocity, motility index (MI; product of the sperm velocity and percentage of motile spermatozoa) and motile density (MD) were determined for each ejaculate. After the initial evaluation the ejaculates were frozen in liquid nitrogen, thawed 24 h later, and assessed for post-thaw motility, velocity, MI and MD. The mean +/- s.e. sperm count and volume for this group of donors was 148 +/- 4 x 10(6)/ml and 3.1 +/- 0.1 ml, respectively. Mean +/- s.e. values obtained from the prefreeze analysis were: motility = 64 +/- 1%, velocity = 30 +/- 0.4 microns/sec, MI = 19 +/- 0.5 microns/sec and MD = 94 +/- 3 x 10(6)/ml. Post-thaw analysis revealed a significant reduction (P less than 0.01) in all values measured. Motility was reduced to 27 +/- 1%, MI was reduced to 5 +/- 0.3 microns/sec, and MD was reduced to 33 +/- 1 x 10(6)/ml. Velocity was the least affected by cryopreservation, being reduced to 21 +/- 0.5 microns/sec (P less than 0.01). Cryopreservation resulted in a marked shift in the frequency distribution of sperm motility and motility index towards subnormal values while in the majority of ejaculates velocity and motile density were maintained in the normal range. Significant differences were noted amongst donors in the percentage change of the various semen measures as a result of cryopreservation. When within-subject coefficients of variation were calculated, velocity was the least variable parameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Impact of Cryopreservation on Spermatozoa from Infertile Men: Implications for Artificial Insemination

“…Cryopreservation decreased the average velocity of the progressively motile spermatozoa in both the infertile patient and fertile groups. This is similar to the decrease of about 30% reported by Keel et al [7]. Although motility and velocity were decreased in post-thaw samples in both patients and donors (compared to original samples), the percentage decrease in motility was significantly greater in patients than in donors.…”

Reasons for rejecting potential donors from a sperm bank program

“…Similarly, for poor cryosurvival the rejection rate of otherwise acceptable donors in our program was comparable to that reported by others (10). Poor cryosurvial also reduces the number of donors (30). The percentage changes in semen quality after cryopreservation were similar in both accepted and rejected donors, suggesting that the effect of freezing and thawing on sperm quality is not different between the two groups (31).…”

Andrology: Pentoxifylline-supplemented cryoprotectant improves human sperm motility after cryopreservation

“…This may be apparent immediately upon thawing (Watson et al, 1992) or may occur later due to sublethal damage (Overstreet and Drobnis, 1993). While cryopreservation decreases the percentage of motile spermatozoa and their velocity (Crister et al, 1987;Keel et al, 1987), it is unclear to what extent membrane damage is responsible for the deleterious effects of cryopreservation on sperm motility (McLaughlin et al, 1992). Decreases in sperm motility have also been attributed to a lowered metabolic rate found in spermatozoa after thawing (Hammerstedt et al, 1990).…”