Blastocyst development potential of D3 low quality embryos

Objective:To investigate the potential of blastocyst development of D3 low quality embryos for blastocyst culturing and freezing. Methods:Two thousand one hundred and eighty embryos of 398 IVF/ICSI patients’ were observed after D3 embryo transfer.The low-quality embryos were cultured by sequential micro-drops and continuously observed blastocyst formation from D3 to D6. Results:(1) A total of 1,546 low-quality embryos were collected,and 426 blastocysts formed in D5-D6.Total blastocyst formation rate(BFR) was 27.56%,of which embryos with grade 6Ⅲ/Ⅳwere 40.87%(318/778),5Ⅰ/Ⅱ28.85%(30/104),4Ⅰ/Ⅱ8.88%(16/180),4Ⅲ/Ⅳ19.72%(56/284),2-3Ⅰ/Ⅱ3%(6/200).(2) Embryos with more blastomeres had a higher blastocyst formation rate.The lower qualities of embryos resulted in lower blastocyst formation rate. Conclusions:Low-quality embryos still have the potential to develop into blastocysts.Therefore,they should not be discarded on D3.They should be continually cultured to D6 in order to reduce embryo wastage and get good clinical results.

Objective： To investigate the potential of blastocyst development of D3 low quality embryos for blastoeyst culturing and freezing. Methods.. Two thousand one hundred and eighty embryos of 398 IVF/ICSI patients＇ were observed after D3 embryo transfer. The low-quality embryos were cultured by sequential micro-drops and continuously observed blastocyst formation from D3 to D6. Results.. （1） A total of 1,546 low-quality embryos were collected, and 426 blastoeysts formed in D5-D6. Total blastocyst formation rate （BFR） was 27.56 %, of which embryos with grade 6 In/Ⅳ were 40.87 % （318/778）, 5 Ⅰ / Ⅱ 28.85% （30/104）, 4I/[[ 8.88% （16/180）,4Ⅲ/Ⅳ 19.72% （56/284）,2-3 Ⅰ/Ⅱ 3% （6/200）. （2） Embryos with more blastomeres had a higher blastocyst formation rate. The lower qualities of embryos resulted in lower blastocyst formation rate. Conclusions.. Low-quality embryos still have the potential to develop into blastocysts. Therefore, they should not be discarded on D3. They should be continually cultured to D6 in order to reduce embryo wastage and get good clinical results.