Cleavage Stage Embryo
A precise embryo quality evaluation is of paramount importance to sustain successful invitro fertilization (IVF) program. In most of the IVF clinics around the world, this quality assessment relies mainly on morphological evaluation of cleavage stage embryos. Embryologists should able to correlate with the features observed at the optical microscopes with the implantation potential of each particular embryo .To achieve this goal, many of the scoring systems are based on the morphological features of dividing embryo have been developed. These embryo classification systems are based on the evaluation of number of blastomeres, degree of fragmentation, the symmetry of the blastomeres, the presence of multinucleation and the compaction status. It is very important that the features that are related to the implantation potential are assessed accurately and similarly. The purpose for this is to illustrate morphological aspects useful for evaluation of the implantation potential of embryos. Cleavage stage embryos are ranges from the 2-cell stage to the compacted morula composed of 8–16 cells. After embryo reaches 8-cell stage, the blastomeres begins to show an increase in cell. Adherence of cell is due to the spread of intercellular tight junctions.