In an IVF treatment, eggs and sperm are fertilized outside the body in a special lab. The fertilized eggs are then cultured for a few days to create an embryo, which is implanted into the woman’s uterus. But do those implanted embryos ensure a better chance of pregnancy and a healthy child?-No, the embryo may have abnormalities and genetic disorders leading to unsuccessful IVF pregnancy. Thus, PGT testing is essential to identify embryo conditions.
This blog post will cover everything you need about PGT, including its types, procedures, benefits, limitations, and ethical considerations.
What is Preimplantation Genetic Testing?
Preimplantation Genetic Testing (PGT) is an embryo test in IVF treatment to select the healthiest embryo before implanting it in the uterus. The test identifies whether the embryo has genetic conditions, chromosomal abnormalities, or inherited disease to ensure that only healthy embryos are transferred. PGT enhances the success rate of IVF, leading to a healthy pregnancy and reduces the risk of miscarriage.
Types of Preimplantation Genetic Testing
The three main types of preimplantation genetic testing are PGT-A (Preimplantation Genetic Testing for Aneuploidy), PGT-M (Preimplantation Genetic Testing for Monogenic Disorders), and PGT-SR (Preimplantation Genetic Testing for Structural Rearrangements).
PGT-A (Preimplantation Genetic Testing for Aneuploidy)
PGT-A identifies chromosomal abnormalities, such as extra or missing chromosomes, which can lead to conditions such as Down syndrome (trisomy 21) or Turner syndrome. It helps select embryos with the correct number of chromosomes, improving the chances of a successful IVF pregnancy.
PGT-M (Preimplantation Genetic Testing for Monogenic Disorders)
PGT-M screens embryos for specific single-gene disorders (monogenic disorders). It is beneficial for couples who have genetic conditions such as cystic fibrosis, sickle cell anemia, or Huntington’s disease. PGT-M can prevent the inheritance of known genetic diseases, allowing couples to have children free from specific genetic disorders.
PGT-SR (Preimplantation Genetic Testing for Structural Rearrangements)
PGT-SR detects structural chromosomal rearrangements, such as translocations or inversions, that can lead to reproductive issues, including recurrent miscarriages or congenital disabilities. Couples who have a history of recurrent miscarriages or are known to carry balanced translocations can benefit from PGT-SR to increase the chances of having a healthy pregnancy.
How Does Preimplantation Genetic Testing Work?
In an IVF process, when embryos are developed enough for testing, they undergo genetic testing ((PGT-A, PGT-M, or PGT-SR). After the test, the embryos’ DNA is analyzed to identify chromosomal abnormalities, gene mutations, or structural rearrangements. Based on genetic testing, the healthy embryo is transferred.
Ovarian Stimulation, Egg Retrieval, and Fertilization
The first step in the IVF process is ovarian stimulation, where the woman undergoes hormonal treatment to stimulate the ovaries to produce multiple eggs. These eggs are then retrieved in a minor surgical procedure and fertilized to create embryos.
Embryo Culture
The embryos are cultured for a few days, typically 5 to 7 days, until they reach the blastocyst stage, when they have developed enough to be tested.
Embryo Biopsy
A small number of cells (usually 5 to 10) are removed from the embryo for genetic analysis. This biopsy is performed at the blastocyst stage, as the embryo is sufficiently developed to allow for accurate testing.
Genetic Testing
The extracted cells are sent to a laboratory, where they undergo genetic testing (PGT-A, PGT-M, or PGT-SR, depending on the reason for the test). The laboratory analyzes the embryos’ DNA to identify chromosomal abnormalities, gene mutations, or structural rearrangements.
Embryo Selection
Based on the genetic testing results, the healthiest embryos are selected for implantation, while those with significant abnormalities are discarded. The selected embryo(s) are then transferred into the woman’s uterus for potential pregnancy.
Benefits of Preimplantation Genetic Testing
Preimplantation Genetic screening helps to increase healthy pregnancy, reduce miscarriage risk, and enhance overall IVF success rate.
- Increased Chance of a Healthy Pregnancy: Genetic screening helps to identify genetic disorders and chromosomal abnormalities in embryos that could result in miscarriage and birth defects. Selecting embryos with the highest chance of leading to a healthy pregnancy increases the likelihood of a successful IVF outcome.
- Reduced Risk of Miscarriage: Couples who experience recurrent miscarriages due to genetic or chromosomal abnormalities can benefit from PGT. By ensuring the embryos are genetically normal, PGT reduces the chances of early pregnancy loss.
- Improved IVF Success Rates: Identifying embryos with genetic abnormalities and selecting healthy embryos increases the success rate of IVF. This test is particularly beneficial for older women with a higher risk of chromosomal abnormalities in their eggs.
- Avoiding Genetic Diseases: PGT-M allows couples who are carriers of genetic disorders to avoid passing those diseases on to their children, ensuring a healthy baby and reducing the emotional and financial burden of managing a genetic condition.
Limitations of Preimplantation Genetic Testing
Not 100% Accurate: False positives and negatives can occur, leading to incorrect conclusions about the embryo’s genetic health. Further testing may be needed to confirm the results.
Limited to Certain Genetic Conditions: PGT may not detect all possible genetic conditions, especially those that are less common or outside the scope of the test.PGT is primarily used to test for genetic disorders, chromosomal abnormalities, and structural rearrangements.
- Emotional and Financial Costs: IVF and genetic testing can be expensive, and multiple cycles may be needed to achieve a successful pregnancy. The process can be emotionally taxing for couples who face challenges during the IVF journey.
- Not Available Everywhere: Not all IVF clinics offer PGT, and the availability of genetic testing may depend on your location, the clinic’s resources, and the specific conditions being tested.
Preimplantation Genetic Testing (PGT) enhances the IVF process by allowing couples to select the healthiest embryos, reducing the risk of genetic diseases and chromosomal abnormalities. This technology significantly boosts IVF success rates, increases the chances of a healthy pregnancy, and offers peace of mind to families.
Common Questions About Preimplantation Genetic Testing (PGT)
1. What is Preimplantation Genetic Testing (PGT) in IVF?
Preimplantation Genetic Testing (PGT) is a genetic test performed on embryos created during IVF to check for chromosomal abnormalities or inherited genetic disorders. The goal is to identify the healthiest embryos before transferring them into the uterus, which increases the chances of a healthy pregnancy and lowers the risk of miscarriage or birth defects.
2. What are the main types of PGT (PGT‑A, PGT‑M, PGT‑SR)?
The three main types of PGT are:
PGT‑A (Aneuploidy) – checks for extra or missing chromosomes (e.g., Down syndrome).
PGT‑M (Monogenic disorders) – screens for single‑gene diseases like cystic fibrosis or sickle cell anemia.
PGT‑SR (Structural rearrangements) – detects structural problems such as translocations or inversions that can cause miscarriage or congenital disabilities.
Each type is chosen based on the couple’s medical or genetic history.
3. How is PGT performed during the IVF process?
In IVF, embryos are cultured for 5–7 days until they reach the blastocyst stage. A small number of cells (5–10) are biopsied from the embryo, and the DNA is sent to a lab for genetic analysis. Based on the PGT report, only genetically normal embryos are selected for transfer into the uterus, while abnormal ones are not used.
4. Who should consider PGT in IVF treatment?
PGT is often recommended for:
Couples with a history of recurrent miscarriages or failed IVF cycles.
Women of advanced maternal age (35+), who have a higher risk of chromosomal abnormalities.
Couples who are known carriers of single‑gene disorders or have a family history of genetic diseases.
At clinics like Sishu Fertility, genetic counseling helps decide whether PGT is necessary for your IVF journey.
5. What are the benefits of PGT in IVF?
PGT can:
Increase the chance of a healthy pregnancy and live birth.
Reduce the risk of miscarriage caused by chromosomal abnormalities.
Improve IVF success rates, especially for older women or those with prior failed cycles.
Help carrier couples avoid passing on inherited genetic diseases to their children.
This makes PGT a powerful tool for couples pursuing IVF in Nepal.
6. Are there any risks or limitations of PGT?
PGT is not 100% accurate; false positives or negatives can occur, so confirmatory tests during pregnancy may still be needed. It also mainly detects specific chromosomal or known genetic issues and may miss rarer or complex conditions. PGT adds to the cost and emotional load of IVF, and not all IVF clinics in Nepal offer advanced genetic testing services.
7. Does PGT increase IVF success rates in Nepal?
Yes, by selecting genetically normal embryos, PGT can increase the chances of implantation and reduce early miscarriages, which improves overall IVF success rates. This is especially helpful for women of advanced maternal age or those with repeated IVF failures.
8. How much does PGT cost as part of IVF treatment in Nepal?
PGT adds an extra cost on top of a standard IVF cycle, and the price depends on the type (PGT‑A, PGT‑M, or PGT‑SR) and the clinic’s lab setup. In Nepal, only a few specialized IVF centers offer PGT, and the total cost includes IVF, embryo culture, biopsy, genetic analysis, and any follow‑up procedures.
9. Is PGT necessary for every IVF patient?
No, PGT is not required for every IVF patient. It is most beneficial for couples with a known genetic risk, recurrent miscarriages, repeated implantation failure, advanced maternal age, or severe male‑factor infertility.
10. Why should I choose Sishu Fertility Clinic for PGT in Nepal?
Sishu Fertility Clinic offers advanced IVF with integrated PGT services, using modern embryo culture systems, blastocyst‑stage biopsy, and reliable genetic testing to select the healthiest embryos. With experienced fertility specialists, clear counseling on benefits and risks, and a focus on personalized care, the clinic is a trusted choice for couples in Kathmandu and across Nepal who want to maximize IVF success and reduce the risk of genetic or chromosomal problems.
