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Updated: Aug 9, 2026
Fluorescence in situ hybridization (FISH) Protocol in Human Sperm
Published on: September 1, 2009
Cytogenetic effects of cryopreservation on human sperm: assessment using an improved method for analyzing human sperm
S Okada1, K Suzumori, Y Yagami
1Department of Obstetrics and Gynecology, Nagoya City University of Medical School, Japan.
Objective:
To evaluate any cytogenetic effects of cryopreservation on human sperm by comparing the frequencies of sperm chromosome anomalies and sex ratios before and after freezing.
Methods:
Using in vitro fertilization of zona-free hamster oocytes, analysis of sperm chromosomes was first performed on portions of fresh human semen samples. The residual semen was then analyzed for sperm chromosomes after cryopreservation for several weeks. Sperm donors were 5 healthy men aged 26-38 years.
Results:
A total of 166 sperm karyotypes were analyzed, 94 before freezing and 72 after freezing. The results indicated no significant differences between fresh and frozen sperm in either frequencies of aneuploidy (fresh: 0%, frozen: 2.8%) or structural anomalies (fresh: 7.5%, frozen: 9.7%). The sex ratios did not differ from the expected 1:1 ratio under either condition.
Conclusions:
The results of these studies indicate that cryopreservation does not exert any cytogenetic mutagenicity on human spermatozoa or alter X/Y ratio of human sperm.
