Embryo scoring as a prognostic tool in IVF treatment

Abstract

A semi-quantitative and non-invasive method for scoring embryos obtained after in-vitro fertilization (IVF) has been defined, aiming at selection of embryos before transfer and at prognostic evaluation of IVF trials. Grading of embryos observed on the inverted microscope was essentially based on the amount of anucleate fragments expelled during early cleavage and on developmental speed. Embryos endowed with a high score were more often associated with pregnancy and in particular with the occurrence of multiple pregnancy. No difference was observed between scores attributed to embryos related to ongoing, aborted or chemical pregnancies. Average embryonic scores corresponding to double and triple transfers differed significantly in failures as well as pregnancies. The better quality of embryos replaced in triple transfers was also apparent from the significantly higher implantation rate per embryo observed in this group. From our results, five criteria including clinical data and embryonic scores can be derived for defining a high risk of multiple pregnancy prior to transfer. It might be warranted to replace only two embryos when these conditions are fulfilled.

Effects of embryo transfer quality on pregnancy and live birth delivery rates

“…There were no changes in the culture conditions during the time period of the study. On the day of transfer the quality of the embryos was evaluated morphological and the best embryos were selected [10,11]. Top embryos were classified on d3 as 6-8 cells A1 and B1 and on d5 as blastocyst 2-5 with grading for inner cell mass and trophectoderm AA, AB or BA .…”

An oocyte score for use in assisted reproduction

“…This is usually achieved either by the extended culture of human embryos to the blastocyst stage [5,6] or by the morphological analysis and selection of the highest quality embryos for transfer [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. More recently, the assessment of zygote quality has been applied [23][24][25][26][27][28][29][30][31][32].…”

The impact of pronuclear orientation to select chromosomally normal embryos

“…Attributes of normal development, such as holoblastic cleavage, absence of fragmentation and blebbing, and short intercleavage interval remain the main markers for embryo selection (22)(23)(24). The core objective of research on embryo selection, therefore, is to develop an objective, noninvasive, accurate, and simple method to choose right embryo.…”