Causes & Treatment
What is PGT IVF, and is it necessary? A fertility clinic answers your questions
Team TRB in partnership with Dr Laura Garcia, Medical Director at Clinica Tambre | 2 May 2020
Your PGT IVF questions, answered
When we asked our community what they wanted to learn more about from our expert partners, the answer was clear: PGT IVF.
So, we opened up the conversation on Instagram and collected your top questions. Then we took them straight to the trusted team at Clínica Tambre — a leading fertility clinic based in Madrid, Spain.
Over the years, we’ve built a library of resources together with their world-renowned clinical team, covering topics like:
- How to navigate switching fertility clinics
- Understanding antral follicle count and fertility over 35
- Are egg donors anonymous in Spain? (Your most searched questions)
All caught up? Let’s dive into what Dr. Laura Garcia, Medical Director at Clínica Tambre, had to say about PGT IVF.
What is PGT / PGS / PGD – and is there a difference?
PGT (Preimplantation Genetic Testing) is an umbrella term that includes both PGS and PGD. It involves testing embryos – usually on Day 5 – by performing a biopsy to examine some of the embryo’s cells for genetic information.
- PGS (Preimplantation Genetic Screening), also called PGT-A, checks for aneuploidy – abnormal numbers of chromosomes in the embryo, which can affect implantation and development.
- PGD (Preimplantation Genetic Diagnosis), now typically referred to as PGT-M or PGT-SR, tests for specific inherited genetic mutations passed down from the mother or father.
What’s the difference between the types of PGT?
- PGT-A (formerly PGS):
Screens for chromosomal abnormalities (aneuploidy) in embryos – helps identify euploid (chromosomally normal) vs aneuploid embryos. - PGT-M (formerly PGD):
Used when one or both parents are known carriers of a specific single-gene (monogenic) disorder. It identifies embryos affected by that genetic condition. - PGT-SR:
Used when one or both parents have a structural chromosomal rearrangement, such as a translocation or inversion. It helps detect embryos with the correct chromosome number and structure.
Who might benefit from PGT?
- PGT-A (PGS):
May be recommended for women of advanced maternal age, those with a history of repeated miscarriage, or prior IVF failure. - PGT-M:
For individuals or couples who carry or are at risk of passing on a known genetic disease. - PGT-SR:
For individuals with known chromosomal structural abnormalities (e.g translocations) identified through karyotype testing.
What is genetic compatibility testing?
Genetic compatibility testing checks whether both partners carry mutations for the same recessive genetic conditions – such as cystic fibrosis or spinal muscular atrophy. Even if both partners are healthy, they may unknowingly carry genes for certain inherited conditions.
This test is recommended for all patients undergoing fertility treatment (including IVF, egg donation, or double donation), to help reduce the risk of passing on recessive genetic disorders to their children.
Some have read that PGT can be controversial. What are your thoughts on this stance?
Of course, all medical tests are not 100% certain.
But, when there is a high risk of creating abnormal embryos that could lead to miscarriages or babies with syndromes, or even implantation failures, it is recommended to discuss individually with each couple or woman before starting the treatment, and to explain the pros and cons of this test.
What are ‘Mosaic Embryos’, and do you think they should be transferred or discarded?
The mosaic embryo is an embryo that has both normal and abnormal cells (some of its cells are absolutely normal in terms of chromosomes, whereas others are abnormal).
The recommendation to transfer or not depends on different aspects: the number of chromosomes involving the mosaicism-for instance sexual chromosomes, 21, 13 and 18 should be excluded, the number of chromosomes involved in the abnormality (one or more chromosomes), etc.
Can testing harm the embryo?
Naturally, it is an invasive test that could eventually harm the embryo. That is the reason why it is extremely necessary to do it in a very good clinic with a high-tech laboratory and senior biologists.
Do people use this method to find out the sex of their embryo?
It could be the case in some countries, but it is not possible in Spain.
How much does PGT cost?
It depends on the type of genetic testing. For instance, in PGT-A, it depends on the number of embryos biopsied. Our team of Patient Care coordinators will be more than happy to answer this type of question if you send an e-mail to information@clinicatambre.com
For someone who has few embryos, a low AMH and is over 40, would you recommend PGT?
Women with a low ovarian reserve, or with only one embryo are the ones that benefit less from this technique.
On the other hand, if a woman is older than 40, there is a high risk of abnormality and then it is necessary to discuss with them if they want to carry on with the test or not.
Thanks to Clinica Tambre for answering our readers’ questions about IVF PGT. Get in touch with their expert team, for more answers, and pathways into treatment.
If you’d like further information on PGT or anything related to this matter, please pop us a message message over on Instagram. Our DMs are always open.
