Analysis of the clinical outcomes of day 2 or day 3 embryo transfer in IVF/ICSI cycles

Objective: To observe the impact of day 2 or day 3 embryo transfer in IVF/ICSI cycles on the clinical results.Methods: A total of 767 infertile patients,who underwent IVF-ET or ICSI-ET treatment from Jan 2005 to Dec 2005 in our reproductive center,were studied retrospectively.576 cycles with day 2 embryo transfer were as D2 group,and 191 cycles with day 3 embryo transfer as D3 group.The main clinical outcomes were compared including average embryo transfer numbers,implantation rate,pregnancy rate,abortion rate,ectopic pregnancy rate and live birth rate.Results: Average embryo transfer numbers,implantation rate,pregnancy rate,abortion rate,ectopic pregnancy rate and live birth rate were 2.28,25.5%,42.0%,12.4%,3.7%,35.2% in D2 group and 2.29,26.6%,47.1%,10%,3.3%,40.8% in D3 group,respectively.No significant differences were observed between these two groups in above data(P0.05).In D3 group,the high quality embryo rate was 53.4% at D2 of culture and then decreased to 40.7% on D3(P0.01).Conclusion: D3 group showed no better clinical results than D2 group.But one more day in vitro culture reduced the number of high quality embryos.