Impact of incubation time of oocytes and sperm on the outcome of in vitro fertilization and embryo transfer.

[Objective] To compare the effect of different incubation time on the outcome of in vitro fertilization and em- bryo transfer (IVF-ET). [Methods] A total of 272 women receiving IVF-ET treatment were included and divided into group A (199 cases) and group B (73 cases). In group A, the oocytes were incubated with the sperm for 4～6 hours, then the oocytes were washed and transferred into the fresh medium. In group B, the oocytes were co-incubated with sperms for 16～18 hours. The fertility rates, cleavage rates, hight quality embryo rates, clinical pregnancy rates and implantation rates were compared between the two groups. [Results] The fertility rate of group A was significantly higher than that of group B (P﹤0.01); The normal fertility rate and better embryo rate of group A was significantly higher than those of group B (P﹤0.05), There was no significant difference between the two groups in cleavage rate, pregnancy rates and implantation rates. [Conclusion] The short time incubation of oocytes and sperm could improve the normal fertility rate and the quality of embryo so that to improve the implantation potency.