The selection of blastocysts with the highest implantation potential usually involves the assessment of the appearance of trophectoderm (TE) and inner cell mass (ICM), and the degree of blastocele expansion, as per the morphological grading system developed by Gardner and Schoolcraft. The greatest scores of all these parameters indicate a blastocyst with high implantation rate; however, the independent predictive ability of each parameter is not very clear. A recent and unique retrospective trial has suggested the superiority of TE over ICM as a more significant independent predictor of live birth outcome in blastocyst transfer cycles. Although the assessment of ICM is critical, the researchers concluded on the importance of a strong TE layer for successful hatching and implantation. Read the full story

The Joint Society of Obstetricians and Gynaecologists of Canada–Canadian Fertility and Andrology Society Clinical Practice Guidelines Committee (JOINT SOGC–CFAS), in 2010, recommended the adoption of single blastocyst-stage embryo transfer when good quality blastocysts are available, considering the association with better implantation and live birth chances compared to cleavage stage embryos. Now, a retrospective study reports that single frozen-thawed blastocyst transfers are associated with significantly lower risk of ectopic pregnancy (EP) when compared to fresh cycles. Read the full story