Blastocyst is called the embryo on the 5th day after fertilization. It consists of more cells (70-100) than 3 day old embryos (6-8 cells).
Blastocyst culture is a process in IVF in which embryos are allowed to develop until the 5th day in the laboratory. Then the most “strong” embryos are selected from the ones that started the procedure. It is essentially a method of selecting the best embryos, which allows for a significant improvement in the success rates of pregnancy in couples that are being applied.
Selection of embryos with the best dynamic in the laboratory.
Greater success rates. Endometrium appears to be more acceptable at day 5 after ovulation.
Smaller percentages of multiple pregnancies if a blastocyst is transferred without reducing the pregnancy rate.
It allows preimplantation genetic diagnosis (PGD), which is done on 3 day embryos and healthy embryos are transported on day 5, at the blastocyst stage. In some cases blastocyst culture allows for the diagnosis of infertility in the couple. While the embryos are of good quality and develop naturally until the 3rd day, then the embryos are converted to moderate quality and / or their growth is stopped.