THE EVALUATION OF THE EFFICIENCY OF THE CRYOPRESERVATION OF HUMAN'S GAMETES AND EMBRYOS IN ASSISTED REPRODUCTIVE TECHNOLOGY PROGRAM

Cryopreservation of gametes and embryos is the essential of modern reproductive medicine. This study aimed to evaluate the efficiency of the native and frozen material in the assisted reproductive technology programs. We investigated 120 semen samples of healthy males (sperm donors). One hundred cases (83%) demonstrate mobility attenuation after defrosting from 67% to 84% versus initial value. During the investigation of 35 native and 23 frozen oocytes, we taped an insignificant decreasing of cleavage rate (from 98,4% to 84,2%, p=0,018). We performed 1289 defrosted gametes and embryos transfers and used closed (n=611, CryoTip, USA) and open (n=678, CryoTop, Japan) type carriers. The majority of indicators was better when we used open type carriers: survival (84,8% for closed type, 95,1% for open type, p <0,0001), pregnancy rate (39,5%, 44,2%, p=0,001), labors rate (72,7%, 67,3%, p=0,003), losses rate (27,3%, 24,3%, p=0,044). The obtained data allow us to conclude that the vitrification of morphologically normal gametes doesn't deteriorate the efficiency of cryo-program and keeps their reproductive status. Open type carriers for vitrification and storage of embryos demonstrates higher survival of embryos, pregnancy rate and lower losses rate after cryopreservation as compared to closed type carriers. Highly likely it occurs due to direct contact of an embryo with liquid nitrogen and high freezing speed. It can be the crucial factor defining the success of the vitrification in open type carriers.

вспомогательные репродуктивные технологии, криоконсервация, эмбрион человека, assisted reproductive technology, human embryo, cryopreservation