Oocyte vitrification technology has made egg-sharing donation easier in China

When infertile women undergoing IVF or intracytoplasmic sperm injection (ICSI) have more than 20 mature oocytes retrieved, at least 15 oocytes are inseminated by their husband’s spermatozoa. The extra oocytes are cryopreserved by vitrification. If the patients became pregnant and have healthy live births, the patients are encouraged to donate their remaining cryopreserved oocytes. Forty-seven egg-sharing donors were recruited after having normal deliveries and they donated their remaining oocytes, totalling 395 cryopreserved oocytes, to 75 recipients. The survival rate of vitrified–warmed oocytes was 83.0%. Following insemination by ICSI, the fertilization and cleavage rates were 83.8% and 89.8%, respectively. Out of 75 recipients, 71 recipients completed the treatment cycles and 30 of them became pregnant with clinical pregnancy and implantation rates of 42.3% and 25.5%, respectively. The birthweight of the new-born infants (22 from singleton and two from one set of twins) were 3344.5 ± 669.1 g and 2425.0 ± 742.5 g, respectively. No birth defects were observed for the live births. These results indicate that oocyte vitrification is an effective methodology for an egg-sharing donation programme, with acceptable pregnancy and implantation rates.This study demonstrated that the strategy of egg-sharing donation with oocyte vitrification is a practical and efficient programme in China, especially with the strict regulations controlling egg-sharing donation. When infertile women undergoing IVF or intracytoplasmic sperm injection (ICSI) have more than 20 mature oocytes retrieved, at least 15 oocytes are inseminated by their husband’s spermatozoa. The extra oocytes are cryopreserved by vitrification. If the patients become pregnant and have healthy live births, the patients are encouraged to donate their remaining cryopreserved oocytes. Forty-seven egg-sharing donors were recruited after having healthy deliveries and they donated their remaining oocytes, in total 395 cryopreserved oocytes to 75 recipients. The survival rate of vitrified–warmed oocytes was 83.0%. Following insemination by ICSI, the fertilization and cleavage rates were 83.8% and 89.8% respectively. Out of 75 recipients, 71 recipients completed their treatment cycle and 30 of them became pregnant (42.3% clinical pregnancy rate and 25.5% implantation rate). The birthweight of new-born infants for 22 singletons and two babies from one set of twins were in the normal range. No birth defects were observed for those live births. These results indicate that oocyte vitrification is an effective methodology for an egg-sharing donation programme, and gives acceptable pregnancy and implantation rates.