BACKGROUND：This retrospective study aimed to investigate pregnancy outcomes when transferred three different sources embryos during early rescue ICSI.

MATERIAL AND METHOD: A total of 805 infertility cases were included. On the third day after insemination, 615 cases transferred with one to three embryos. The pregnant rate, abortion rate and live birth rate were compared in three groups.

RESULTS: ①Pregnant group with younger female age, less starting gonadotropin dose, fertilization and embryonic score were better. ②Pregnant rate, early abortion rate and ectopic pregnancy rate were the lowest in only ICSI sources embryo. Multiple pregnancy rate and the birth rate of low weight babies at term was lower in the transferred both IVF and ICSI sources embryo group. ③The sex ratio of the newborn in the three groups were different significantly, IVF with more girl, ICSI with more boy, and IVF/ICSI group was the most balanced. ④Both cleavage rate and good quality embryo rate were the predictors of clinical pregnancy and live birth.

CONCLUSIONS: Using the early rescue ICSI based on short-term insemination was helpful to increase the utilization rate of the embryo, and improve the clinical pregnancy outcome. While more researches are needed on the safety of offspring.