The embryo transfer process is a procedure that starts with fertilization followed by the embryo culture. During the time the embryos stay in the culture, their quality is evaluated to determine which embryo and how many will be transferred to the uterus. This procedure finishes when the embryos are deposited in the uterus

Frequent Doubts about the Embryo Transfer Process

Even though every case is unique and in assisted reproduction it’s impossible to generalize, having arrived at the fifth day of development, the blastocyst allows us to better select which embryo to transfer. This leads to higher pregnancy rates.

In cases where on the third day we have a limited number of high-quality embryos, waiting until the fifth day does not offer any advantages as we already have the embryos selected.

A blastocyst is an embryo after 5 or 6 days of embryonic development. It has a complex structure with approximately 200 cells and is the phase just before implantation into the mother’s uterus. Embryos that reach this phase have a higher potential for implantation.


No, only embryos with a sufficient quality can be cryopreserved. This way we can guarantee that the cryopreserved embryos have a high potential for resulting in pregnancy.

Embryos are classified according to their morphological characteristics. The embryologists evaluate the number and symmetry of the cells and determine if they are fragmented or not.

Taking into consideration these and other parameters, they can be classified with a letter according to their quality. Quality is classified on a scale between “A” and “D”. “A” and “B” classified embryos offer the highest possibility for pregnancy.