Feasibility of selecting viable embryos from poor quality embryos by blastocyst culture

Objective To investigate the feasibility of screening viable embryos from poor quality embryos by extending blastocyst culture. Methods 538 D3 poor quality embryos from 142 cases IVF /ICSI treatment were collected after embryo transfer or freezing,and observe the blastocyst formation by blastocyst cultured for up to the sixth days( D6). The embryos were divided into four groups( 4 cells grade Ⅰ /Ⅱ /Ⅲembryos,5 cells grade Ⅰ /Ⅱ /Ⅲ embryos,6 ~ 9 cells grade Ⅲ embryos and exceed 9 cells grade Ⅰ /Ⅱ /Ⅲembryos) according to different blastomere and grade,and then compared the blastula development. Results The blastula formation rate and the high-quality blastula rate from D3 poor quality embryos were 65. 6% and 51.3%,the blastula formation rate of the four groups were 55. 6%,56. 6%,70. 4% and 66. 7%,there were significant difference among the four groups( P 0. 05). And the high-quality blastula rate were 8. 9%,32. 6%,61. 0% and 63. 3%,there were significant difference among the four groups( P 0. 05). Conclusions Extending blastocysts cultured can select the developmental potential embryos from those poor quality embryos remnant effectively,and make better use of the embryos.