Blastocyst quality scoring based on morphologic grading correlates with cell number

Blastocyst quality score (BQS), first reported by Rehman et al., is a numerical blastocyst-morphology grading system based on the criteria established by Gardner and Schoolcraft. We demonstrate a positive correlation between the calculated BQS score and cell number by staining thawed human embryos and suggest that BQS can be applied to evaluate culture systems clinically. (Fertil Steril (R) 2010;94:1135-7. (C)2010 by American Society for Reproductive Medicine.)