Silvia Azaña, an embryologist at inviTRA, explains in this video when embryo culture is performed in an assisted reproduction treatment like IVF:
The laboratory culture of invitro fertilization begins after obtaining the eggs through follicular puncture. The day of the puncture is known as day zero of embryionic development as this is when fertilization the union of the egg and sperm will occur. Initially the eggs will be cultured without removing the layer of granulosa cells surrounding them a process known as decumulation.
However, depending on the IVF technique that will be applied to fertilize the eggs, the next step will be:
If it is conventional IVF, the eggs are combined with the sperm without decumulating.
If it is ICSI, the eggs are decumulated and then the intracytoplasmic sperm injection will be performed.
The cultivation of embryos obtained after fertilization will:
Continue until the day when the embryos are transferred to the maternal uterus, which is usually on day three or in the blastoyst stage (day 5 to 6).
Are vitrified, usually on day 5 to 6.
Are discarded for not continuing their development.
It is worth noting that those remaining embryos that are vitrified can also have different destinations. future personal use, donation for research, transfer to other couples for reproductive purposes, or sessation of their preservation when the woman's reproductive stage has ended.
