Blastocyst

The 5th to 6th day of an embryo’s development after fertilisation; blastocysts have a higher chance of successful implantation in the uterus. The blastocyst stage is an early embryonic stage of a human foetus, consisting of approximately 120 cells. In IVF, the embryo is transferred to the woman’s uterus at this stage. The remaining blastocysts can be frozen for further attempts.