Blastocyst culture

Normally in standard IVF embryos with six to eight cells will be transferred to the uterus on day three after egg collection. Recently there has been a new development in the culture system and the embryos can be extended in culture until day five or six at the blastocyst stage. Mostly only healthy embryos reach this development stage, about 40% to 50% of fertilized oocytes. There is some patient variation. Embryos can be evaluated for their development potential on day three before blastocyst culture is continued.