Preimplantation Genetic Testing (PGT)
In short: PGT (preimplantation genetic testing) checks embryos for genetic diseases and chromosome problems during IVF, before transfer. A few cells are taken from each embryo on day 3–5 and tested. There are three main types: PGT-M (single-gene diseases), PGT-SR (chromosome structure) and PGT-A (chromosome number). It helps choose a healthy embryo, but no test is 100% certain.
What Is PGT?
Preimplantation genetic testing (PGT) is a genetic screening method used during IVF. It looks at the genes of an embryo at an early stage. This can find some genetic diseases and chromosome problems.
At DrHIT Cyprus IVF Center, PGT is part of our advanced IVF lab work. It helps us choose healthy embryos before transfer.
What Is the Purpose of PGT?
PGT gives early information about genetic diseases or chromosome problems a baby might have. It helps stop these conditions from being passed on.
So PGT is especially advised when a couple has a known genetic risk.
PGT can:
- lower the risk of inherited genetic diseases
- help prevent chromosome problems
- raise the chance of choosing a healthy embryo
- improve implantation rates in some patients
How Is PGT Done?
PGT is done during IVF. After the eggs are collected and fertilized, the embryos grow in the lab.
When the embryos reach day 3 to day 5, one or more cells are carefully removed. This is called a biopsy. The cells are sent for genetic testing.
Based on the results, healthy embryos are chosen and placed in the womb.
At DrHIT Cyprus IVF Center, this is done with advanced embryology lab systems, following Cyprus IVF standards.
Types of PGT
What Is PGT-M?
PGT-M finds monogenic diseases. These are diseases caused by a change in a single gene.
Examples include:
- cystic fibrosis
- sickle cell anemia
- thalassemia
- hemophilia
PGT-M is advised for couples who are known carriers of a specific inherited disease.
What Is PGT-SR?
PGT-SR checks for changes in the structure of chromosomes. It is advised especially for couples with:
- balanced chromosome translocations
- repeated miscarriages
- known chromosome structure problems
PGT-SR helps choose embryos with a normal chromosome structure.
What Is PGT-A?
PGT-A (testing for aneuploidy) is widely used to find an abnormal number of chromosomes.
It can find conditions such as:
- Down syndrome
- Turner syndrome
- other problems with chromosome number
PGT-A is often advised for women over 35 or couples with repeated IVF failure.
When Is PGT Recommended?
PGT may be advised for:
- couples who carry a genetic disease
- women aged 35 or older
- repeated pregnancy loss
- a previous child with a genetic disorder
- repeated IVF failure
- severe male-factor infertility
- a family history of inherited disease
Which Genetic Disorders Can PGT Detect?
PGT can find many chromosome problems and single-gene diseases.
Examples include:
- Down syndrome
- Turner syndrome
- cystic fibrosis
- thalassemia (alpha and beta)
- hemophilia
- sickle cell anemia
- fragile X syndrome
- spinal muscular atrophy (SMA)
- Gaucher disease
- Tay-Sachs disease
- Wilson disease
- Niemann-Pick disease
- Fanconi anemia
With modern methods such as NGS (next generation sequencing), it is possible to screen for hundreds or even thousands of genetic conditions.
Frequently Asked Questions
What is preimplantation genetic testing (PGT)?
PGT is a test done during IVF. Embryos are checked for genetic problems, so healthy embryos can be chosen for transfer.
How long does PGT take?
PGT is done during the IVF cycle. The genetic test usually takes a few days.
Is PGT 100% successful?
No. PGT greatly improves embryo selection, but no medical test can guarantee 100% success.
Is PGT expensive?
PGT adds to the cost of IVF. But for couples with a genetic risk, it may prevent serious inherited diseases and repeated pregnancy loss.
Is PGT ethical?
PGT raises ethical questions because it involves choosing embryos. But many people see it as a valuable way to prevent severe genetic diseases.
Scientific Background
Advances in genetics now make it possible to diagnose more and more inherited diseases. Since the human genome was mapped, genetic testing has grown fast.
Humans have 46 chromosomes and about 20,000–25,000 working genes. Some conditions, such as cystic fibrosis, can be caused by hundreds of different gene changes.
PGT lets embryos be checked for genetic risks the parents are known to carry. Today, wide carrier screening panels can test for hundreds of inherited disorders.
Important Points
- PGT must be done by experienced embryologists and genetic specialists.
- Embryo biopsy carries a small risk.
- Genetic counselling is strongly advised before PGT.
- PGT improves embryo selection but does not fully replace testing during pregnancy.
Conclusion
Preimplantation genetic testing (PGT) is an advanced genetic screening method used during IVF. It helps lower the risk of inherited diseases and chromosome problems.
At DrHIT Cyprus IVF Center, PGT is part of our full IVF programs. It supports safer embryo selection and better pregnancy outcomes, using internationally recognised lab standards.
If you are thinking about PGT, talk to a fertility specialist about your medical history and genetic risks. They can tell you if it is right for you.