Our clinic will do either. Basically you are paying for the treatment so what you say goes. Obviously the FS and embryologists will give you their recommendations. Most of the time is there are three or less embryos our clinic will do a D2 or D3 ET. Any more than that is usually a D5/blast ET. BW's advice is excellent. i cant really add more to that except that there is a lot of science and a lot less art that goes into growing a baby from IVF Good luck with whatever you decide x