In todays’ article, we are going to take a look at the procedure that most, if not all IVF clinics in today's day and age perform to ensure their patients a successful treatment leading to fulfilling their dream of becoming parents: Embryo selection. But what is embryo selection? And why is it recommended?

The importance of selecting the best embryo

As technology in the field of reproductive medicine has advanced, medical professionals tend to recommend the transfer of only one single embryo. Transferring only the embryo of the highest quality is the best way to ensure a pregnancy without complications. This is due to the reason that double pregnancies can lead to problems such as premature birth or delayed intrauterine growth.

It is also very important for the embryos in an IVF treatment to reach the blastocyst stage, which is usually around day 5 or 6 of embryonic development. Not only is this the best moment to evaluate their condition, but a day 5 embryo also have a higher chance of implanting.

Embryo selection: criteria

The decision of which embryo is selected by embryologists as the one with the highest quality is based on three factors:

• Morphology – The number and appearance of the cells that make up the embryo
• Genetic – The embryos chromosome composition
• Kinetic – The rate of cell division

Thanks to the evolution of technology and the improvement of available tools helping the embryologists choose the embryo with the best quality, success rates of implantation and births have been at an all-time high.

Time-lapse technology

In comparison to embryo selection in the past, which was conducted by periodically observing the embryos under the microscope, altering the continuity of their culture, new technology like the time-lapse technique allows embryologists to monitor the embryonic development without altering the incubation conditions.

In our laboratories at IVF-Spain, our team of embryologists uses the Geri Plus incubator which captures an image of the embryo every five minutes up until they reach blastocyst stage at around day 5 or 6. This way, a large amount of important information can be obtained and help our embryologists to evaluate cell division without having to remove the embryos from the incubator.

Furthermore, a characteristic unique to Geri Plus is that it has six independent spaces with its own high-resolution chamber. Since each patient has their own incubator, we can guarantee personalised conditions for every embryo in which it won’t be affected by the development of the other embryos.

By keeping the conditions in which the embryo develops steadily within the time-lapse incubator and through the precise evaluation by our embryology team, we are able to select which embryos are most likely to implant and lead to a successful pregnancy and therefore improve the success of the treatments, improving both the rate of implantation and the rate of births.

How genetics influence embryo selection

As already mentioned previously, genetics is one of the three criteria that influence the selection of the best embryo. But why is that?

Embryos that show genetic or chromosomal alterations, also called aneuploid embryos, may have the chance to implant correctly, but oftentimes lead to spontaneous miscarriage or the birth of a child with a chromosomal abnormality such as conditions like Down-Syndrome.

This is why at IVF-Spain we offer advanced techniques like preimplantation genetic testing, now known as PGT-A (Preimplantation Genetic Testing for Aneuploidy), when selecting the best embryo. This test can detect possible alterations in the 23 pairs of chromosomes that make up each cell of the embryo and is performed by an embryo biopsy in which some cells are extracted from the developing embryo (around day 5 of its growth).

If you would like to know more about Embryo selection, Time-Lapse technology or PGT-A feel free to visit our website or contact us.