Increased cryo-survival rate in ejaculated human sperm from infertile men following pre-freeze in vitro myo-inositol supplementation / 대한생식의학회지

OBJECTIVE: To investigate the effects of in vitro myo-inositol (Myo-Ins) supplementation of cryopreserved human semen on the cryo-survival rate (CSR). METHODS: Semen samples were obtained from 41 infertile men. Following routine semen analysis, each sample was divided into two equal aliquots (0.5 mL each). One aliquot was treated with 1 mg of Myo-Ins dissolved in 10 µL of sperm preparation medium. The second aliquot was treated with 10 µL of the same medium (control). Both aliquots were incubated for 20 minutes prior to freezing to slow the freezing process. The frozen samples were examined for post-thaw percentages of total motility (TM), progressive motility (PM), and the CSR, defined as the percentage of post-thaw TM divided by the percentage of pre-freeze TM and multiplied in 100. The results were expressed as median and interquartile range (25th and 75th percentiles). RESULTS: The pre-freeze TM (50% [30%–50%]) and PM (35% [20%–35%]) were significantly higher than the post-thaw TM and PM in the Myo-Ins group (15% [10%–35%] and 10% [5%–20%]; p < 0.001 and p < 0.001, respectively) and the control group (10% [6%–30%] and 5% [3%–15%]; p < 0.001 and p < 0.001, respectively). The CSR of the 41 semen aliquots supplemented with Myo-Ins (40% [25%–70%]) was significantly higher than that of the control samples (30% [13%–58%], p=0.041). The CSR of the 26 abnormal semen samples that were supplemented with Myo-Ins (38% [20%–50%]) was significantly higher than that of the control samples (23% [12%–30%], p=0.031). CONCLUSION: In vitro Myo-Ins supplementation of ejaculated human sperm from infertile men resulted in a significant increase in the CSR in samples with abnormal pre-freeze sperm parameters.

Rapid freezing versus Cryotop vitrification of mouse two-cell embryos / 대한생식의학회지

OBJECTIVE: To compare our in-house method of embryo freezing with Cryotop vitrification in terms of immediate survival, subsequent cleavage and blastocyst formation, and cell numbers in blastocysts. METHODS: Two-cell mouse embryos were randomly allocated into three groups: a non-frozen control group (group 1, n=300), a group that underwent Cryotop vitrification (group 2, n=300), and a group that underwent our in-house freezing method (group 3, n=300). RESULTS: There were no significant differences between groups 2 and 3 in the immediate survival rate (96.3% vs. 98.6%, respectively; p=0.085), the further cleavage rate (91.7% vs. 95.0%, respectively; p=0.099), or the blastocyst formation rate (80.7% vs. 78.6%, respectively; p=0.437). The cell numbers in the blastocysts from groups 1, 2, and 3 were comparable (88.99±10.44, 88.29±14.79, and 86.42±15.23, respectively; p=0.228). However, the percentage of good-quality blastocysts in the Cryotop vitrification group was significantly higher than in the group in which our in-house method was performed, but was lower than in the control group (58.0%, 37.0%, and 82.7%, respectively; p < 0.001). CONCLUSION: At present, our method is inferior to the commercial Cryotop vitrification system. However, with further improvements, it has the potential to be useful in routine practice, as it is easier to perform than the current vitrification system.