How does genetic testing work?


Have you always wondered about the connection between genetic testing and fertility? Have you struggled to understand the differences among the main types of genetic tests? If so, this is the right article for you. 

Preimplantation genetic diagnosis (PGD), also known as PGT-M or PGT-SR, is used to study the genetic heritage of embryos born from an IVF procedure. Testing occurs before embryo transfer to avoid transmitting a genetic disease present in the future parent’s genes, such as hemophilia. 

PGD is suited for people who are carriers of a genetic anomaly. In a couple, it can be both members but also just one. Not necessarily are the parents genetically ill, but they can nevertheless be carriers. 

Another type of testing is PGT-A (preimplantation genetic testing for aneuploidies). It consists of detecting anomalies in the number of chromosomes of the embryo. This process aims to maximize the chances of IVF success by avoiding miscarriages. 

The term aneuploidy means that the cell has an unusual number of chromosomes, leading to genetic diseases like trisomy 2. An aneuploid cell is a frequent cause of embryo implantation failures. PGT-A is made for infertile couples who are going through IVF. 

When do we recommend using PGT-A? 

1. if a woman’s age is superior to 35 

2. if the couple has struggled to have successful implantation for the embryo 

3. if the woman has had a lot of miscarriages (generally more than three) 

4. if the couple’s previous child had some genetic anomaly 


PGT-SR is a more advanced method to see whether there are translocations, deletions, inversions or other pathologies in each chromosome. PGT-M or PGT-A can be done in the blastocyst phase of the embryo, meaning between the 5th and 6th day of embryo development. Doctors then can narrow the field and the number of embryos to only those chromosomally and genetically sound and give them a good chance to continue their development. The procedure starts with ovarian stimulation, followed by the IVF process, a sampling of some cells of the embryo, a genetic test and the final transfer of the embryo. 

At Unica clinics, we primarily use PGT-A and PGT-M. If you have doubts, it is essential to talk about PGD testing with your gynecologist, geneticist or an IVF expert like the ones we have at Unica. During this consultation, you find out which one of these methods is suitable for you and which one of them you will need for your IVF treatment. 

Our medical team is here to advise and support you in all the steps of your journey. You can find out more by contacting your future or current coordinator to help you fulfill your dream of becoming a parent!

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