The blastocyst is the stage of embryo development when the embryo reaches the uterine cavity to implant (day 5 after fertilization). As a result, in IVF cycles, it is necessary to keep the embryo in the incubator for five days to allow it to reach the blastocyst stage.
This technique is usually indicated for patients with repeated implantation failures, in cases where there is a risk of hyperstimulation, when a single embryo is transferred, to select embryos with higher implantation potential, and in a PGD, etc. Pregnancy rates with blastocysts are very similar to those obtained with embryos transferred at the eight-cell stage (on day 3).
If you become pregnant, your pregnancy can be considered a normal pregnancy. It is advisable to notify your obstetrician that you conceived using assisted reproduction techniques.