Effects of cryopreservation on penetration ability of human spermatozoa into bovine cervical mucus.

Cryopreserved sperm exhibit lower fertilizing capacity in comparison to fresh sperm, partly due to effects of glycerol as the common cryoprotectant medium. Since standard semen analysis is not a good predictive method to assess sperm fertilizing capacity, functional tests like cervical mucus penetration may provide more useful information. A total of 24 semen samples were examined before and after cryopreservation for sperm parameters as well as number and motility of penetrated sperm into bovine cervical mucus (BCM) as an alternative for human cervical mucus. Freezing and thawing procedures have negative effects on sperm penetration into cervical mucus. No significant relation was noticed between sperm motility percentage or its penetration into BCM before and after cryopreservation, which denotes the variability in resistance of sperm to damaging effects of freezing.