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There has been a miraculous advancement in the field of fertility and reproductive medicine with respect to genetics and an IVF doctor has to ensure no genetic fault in the embryos before transferring them to the uterus.
Preimplantation genetic testing (PGT) is a technique used in IVF to screen embryos for genetic abnormalities. The goal of genetic testing of embryos in IVF is to ensure the embryo has the right number of chromosomes, as well as that the embryo is free of specific genetic mutations which could lead to abnormalities in the babies as well as recurrent pregnancy losses.
The genetic screening in IVF helps increase the chances of a successful pregnancy. Also, if a patient has experienced 2-3 IVF failures or has a genetic or hereditary disorder, the IVF doctor may recommend genetic screening before proceeding with treatment. This means a higher IVF success rate with PGT testing. It also reduces the risk of passing on hereditary diseases.
As of 2024, around 15-20% of IVF cycles in India involved PGT. This is a very significant increase from previous years, reflecting its growing adoption among fertility clinics.
What is Preimplantation Genetic Screening in IVF?
The purpose of PGT is a technique to identify embryos that are free from chromosomal disorders or specific genetic mutations. After the eggs are fertilized into an embryo, doctors take a cell from each embryo and sends it for testing. Since the procedure involves taking only a single cell from the embryo without harming it, couples can proceed with a safer IVF process.
By genetic screening before IVF, doctors increase the chance of a successful pregnancy via IVF.
Must Read: How to Read a Semen Analysis Report?
Understanding the Different Types of PGT:
- PGT-A (Aneuploidy Screening) detects abnormalities in chromosome numbers. This can be done for several blood disorders as well as Down’s syndrome, which occurs due to an extra copy of chromosome 21. Data from the Asian Center for Reproductive Medicine indicates that PGT-A reduces the risk of miscarriage by up to 50% in women with a history of recurrent pregnancy loss or advanced maternal age.
- PGT-M (Monogenic Disease Screening) screens for specific genetic disorders. Suppose you have a family history of a genetic disease, like Hereditary Spherocytosis. PGT-M is a test during IVF that checks embryos for this specific disease before pregnancy, avoiding the risk of passing on that condition.
- PGT-SR (Structural Rearrangements Screening) checks for chromosome problems where parts are swapped or rearranged. Preimplantation genetic testing SR helps spot genetic issues that could lead to health problems or pregnancy loss, ensuring healthier embryos are chosen for IVF.
What Does the PGT Test for in IVF?
The preimplantation genetic testing in IVF looks for issues like Down’s syndrome, muscular dystrophy, hereditary cancers of ovaries, breasts, ankylosing spoldylitis, hemoglobinopathies, sickle cell anemia. Now we will explain how it detects other genetic issues like dystrophy, thalassemia and more. These two specifically are caused by gene mutation.
For dystrophy, PGT identifies mutations in genes responsible for muscle function. In thalassemia, it screens for mutations in the HBB gene that causes abnormal hemoglobin production.
Embryos undergo biopsy at the blastocyst stage, and cells are analyzed for these mutations. By picking healthy embryos with the right genetic makeup, PGT increases the chances of parents feeling more confident that their baby will be healthy. Thus, every excellent IVF expert/ facility will always advise for genetic screening before IVF.
According to a study by the Indian Society of Assisted Reproduction (ISAR), PGT-A can improve IVF success rates by approximately 20-30%.
Overview of Process, Technologies, and Timeline for PGT:
Preimplantation genetic diagnosis (PGD) begins after the IVF procedure. Once eggs are fertilised, embryos are grown in the lab for about 5 days, That’s when they reach the blastocyst stage. A biopsy is then performed, removing a few cells from the embryo. These cells are analyzed for genetic abnormalities using advanced techniques such as Next-Generation Sequencing (NGS), Fluorescence In Situ Hybridization (FISH), or Array Comparative Genomic Hybridization (aCGH).
The genetic testing usually takes about 1-2 weeks. Results from PGD help determine which embryos are genetically healthy and should be transferred to the uterus. The entire IVF-PGD process, from fertilisation to embryo transfer, typically takes about 2-3 weeks, depending on the timeline of the embryo testing. PGD is crucial for preventing genetic diseases as well as for IVF success rate with the PGT testing.
Does IVF genetic testing test for Down’s Syndrome? How?
Down’s Syndrome happens when there’s an extra chromosome 21. This extra chromosome causes physical and developmental differences, including learning challenges and some health issues.
Yes, IVF genetic testing can check for Down’s Syndrome and ensure that your child does not suffer from it. During IVF, the preimplantation genetic testing helps find embryos with the right chromosomal makeup in such cases. Then the IVF doctors can choose the healthiest ones to implant. This genetic testing embryo IVF ensures least risk of having a baby with Down’s Syndrome.
Also Read: What are the Chances of Having Twins with IVF?
How Does PGT-A Improve Success Rates in IVF?
Aneuploid embryos are those with too many or too few chromosomes. These often lead to failed implantations or miscarriages. Genetic screening before IVF improves success rates in IVF by selecting embryos with the correct number of chromosomes.
By using preimplantation genetic testing for Aneuploidy for these abnormalities, the IVF specialist ensures only chromosomally normal, healthy embryos are transferred. This targeted approach is especially helpful for women over 35 or those with a history of miscarriage or failed IVF cycles.
IVF Genetic Testing Pros and Cons:
Please check the detailed pros and cons of IVF genetic testing to understand its benefits in identifying genetic disorders and the potential limitations to consider before making a decision.
Pros
- Prevent passing on serious genetic conditions to the baby, such as Down’s syndrome, muscular dystrophy, thalassemia, metabolic disorders and more. It ensures a healthy pregnancy.
- PGT lowers the chance of miscarriages caused by chromosomal abnormalities/hereditary genetic abnormalities.
- IVF success rate with the PGT testing goes up by several notches as a healthy embryo is implanted.
Cons
- IVF genetic testing cost is often higher than a normal IVF cycle, but then for certain cases genetic testing is needed for patients who actually need it or else they would suffer to conceive or bear children with genetic abnormalities.
- The process involves taking cells from the embryo, which may seem difficult technically to certain IVF centres which are not trained for it.
- There’s a tiny chance that the embryo might be harmed during the biopsy. But that’s a rare chance usually.
- Waiting for test results can be stressful for some people. So a good IVF centre will always provide you emotional therapy support.
- Not all fertility clinics offer PGT, so go for IVF centres that have high IVF success rate with PGT testing.
Is genetic screening worth it?
With a 20-30% increase in IVF success rates and a 50% reduction in miscarriage risk, Preimplantation Genetic Testing (PGT) is becoming a vital tool in Asia and India. Clinics offering genetic screening in IVF provide advanced solutions to enhance your IVF success rate with the PGT testing. Thus, we strongly advise that for a successful and healthy pregnancy, you must go ONLY for IVF clinics with genetic testing embryo IVF that too at a feasible IVF genetic testing cost.
Common Questions on Genetic Testing:
