Role of Genetic Testing in IVF: PGD vs PGS

If you are at a point where you’re thinking of undergoing IVF treatment, you may already be aware, it’s not merely a physical process. It’s an emotional, medical, and very personal journey. And when it comes to making every cycle worth it, choosing genetic testing in IVF is a crucial decision to be safe from future worries.

With terms like PGD, PGS, PGT-M, and PGT-A thrown around, it’s likely to feel overwhelmed. But being aware of the significance of genetic testing in IVF, and more importantly, what it means for your IVF journey gives much clarity, especially while dealing with infertility or known genetic risks.

What is Genetic Testing in IVF?

Genetic testing in IVF refers to examining embryos for abnormalities in genes or chromosomes before implantation. This enables the IVF specialists to spot and transfer only the healthiest embryos, enhancing the success chances of pregnancy while minimizing the risks of miscarriage or genetic disorders.

The two main types of IVF genetic testing:

• PGD (Preimplantation Genetic Diagnosis), now known as PGT-M Pre-implantation Genetic Testing for Monogenic Disorders) 
• PGS (Preimplantation Genetic Screening), now known as PGT-A (Pre-implantation Genetic Testing for Aneuploidies 

These fall under the broader umbrella of Preimplantation Genetic Testing (PGT) and are done during an IVF cycle, just after embryo fertilization and before embryo transfer.

Why Consider IVF Genetic Testing?

Genetic testing during IVF isn’t mandatory, but it’s often recommended in specific cases, especially when the goal is to avoid inherited disorders or improve the chance of a successful pregnancy.

You might be a candidate for IVF genetic testing if:

• You or your partner are carriers of a genetic condition 
• You’ve experienced repeated IVF failures 
• You’ve had multiple early miscarriages 
• You’re over the age of 35, where the risk of chromosomal issues increases 
• You want to reduce the emotional and financial toll of unsuccessful IVF attempts 

Understanding PGD (PGT-M): Targeted Testing for Inherited Conditions

PGD, or Preimplantation Genetic Diagnosis, now called PGT-M (Preimplantation Genetic Testing for Monogenic conditions), screens embryos for certain single-gene disorders that one or both parents are carrying.

These conditions can often be serious, lifelong, and sometimes fatal, so early identification is crucial.

Conditions Commonly Detected Through PGD / PGT-M

Following are some of the most common inherited diseases tested through PGD:

1. Thalassemia

A blood disorder that affects the body’s ability to produce hemoglobin. Children with major thalassemia remain dependent on lifelong blood transfusions. Risk is around 25% chance if both parents are carriers

2. Cystic Fibrosis

A genetic condition affecting the lungs and digestive system. It leads to thick mucus buildup, frequent infections, and shortened life expectancy. Risk is higher if both partners are carriers.

3. Sickle Cell Anemia

This disorder causes red blood cells to develop a sickle shape, causing painful episodes, anemia, and organ damage. Commonly seen in people of African, Indian, Middle Eastern descent.

4. Tay-Sachs Disease

A fatal disorder that damages or destroys nerve cells in the brain and spinal cord. Symptoms begin in infancy and progress at a fast rate.

5. Muscular Dystrophy

A group of genetic disorders causing progressive muscle weakness. Some forms can be fatal in childhood. Inheritance is often X-linked (affects males more severely)

6. BRCA Gene Mutations

These increase the risk of breast and ovarian cancers. Testing embryos lowers transmission of this high-risk gene.

What is PGS (PGT-A)? Screening for Chromosomal Abnormalities

PGS, or Preimplantation Genetic Screening, now known as PGT-A (Preimplantation Genetic Testing for Aneuploidy), evaluates whether an embryo has the correct number of chromosomes.

A normal embryo has 46 chromosomes (23 pairs). An incorrect number is called an aneuploidy, which may result in implantation failure, early miscarriage

Common Conditions Detected Through PGT-A

1. Down Syndrome (Trisomy 21)

Caused due to an extra copy of chromosome 21. It causes developmental delays, intellectual disorders, and physical features such as poor muscle tone and upward-slanting eyes.

2. Turner Syndrome (Monosomy X)

Develops when a female lacks one X chromosome. It results in short stature, infertility, and heart conditions.

3. Edwards Syndrome (Trisomy 18)

It’s a severe condition where babies are born with malformed organs and usually don’t survive past infancy.

4. Patau Syndrome (Trisomy 13)

Causes severe brain, heart, and spinal defects. Life expectancy is even less than a year.

PGD vs PGS in IVF: What’s the Difference?

Here’s a clear comparison to help you decide which test might be right for your situation:

IVF PGD and PGS: Step-by-Step Process

Whether you choose PGD IVF or PGS IVF, the process usually includes the following steps:

1. Genetic Counseling: You meet with a counselor to evaluate your risk profile, family history, and finalize which test is important. 
2. Standard IVF Cycle: Doctor retrieves the eggs, fertilizes them and creates embryos in the IVF lab. 
3. Embryo Biopsy: On day 5 or 6, embryologists extract a few cells from each embryo. 
4. Genetic Testing (PGT-M or PGT-A): They send these cells to a specialized lab for testing. 
5. Embryo Selection: Embryologists and IVF specialists select embryos that don’t show targeted disorder or chromosomal defects 
6. Embryo Transfer: Then, the doctor transfers the healthy embryo into the uterus for implantation. 
7. Pregnancy Monitoring: You continue with routine check-ups like any IVF cycle. 

Benefits of PGT-M (PGD IVF)

• Prevents passing on genetically inherited or life-altering diseases 
• Highly beneficial for carrier couples who have known family conditions 
• Helps to eliminate diseases from coming generations 
• Prevents emotionally and ethically difficult decisions later in pregnancy 
• Ensures a good start of the pregnancy with healthier embryo from the start 

Benefits of PGT-A (PGS IVF)

• Finds out embryos with higher implantation potential 
• Reduces the number of failed IVF cycles and miscarriages 
• Benefits older women or couples with limited embryos 
• Allows for elective single embryo transfer (eSET) without affecting IVF success chances 
• Enhances overall IVF efficiency and cost-effectiveness 

Is IVF Genetic Testing Right for You?

While IVF genetic testing offers several advantages, it’s not mandatory for everyone. It’s better to consider IVF genetic testings like PGD or PGS if: 

• You or your partner are a carrier of known genetic condition 
• You’ve gone through two or more failed IVF cycles 
• Your age is above 35, and embryo quality is a major concern 
• You’ve been through multiple early pregnancy losses 
• You wish to ensure good health of future children 

Always discuss with your fertility specialist and a genetic counselor to make a well-informed decision based on your unique needs and challenges.

If you have a higher chance of passing on hereditary condition, the IVF PGD process lets you screen embryos and pick the healthiest one before implantation, helping reduce risks later on.

Embrace your unique journey of IVF treatment without comparing it with any other story. If important, utilize tools such as PGD and PGS that make you feel more confident along the way. Genetic testing makes a huge difference in protecting your baby from a genetic disorder and giving you the best chance of a healthy pregnancy. 

The decision may not always come easy but it’s well-informed. And that’s what empowers couples to move forward with clarity, hope, and confidence.

Connect with us at Pristyn Care today to plan a safe IVF treatment journey with our experienced IVF specialists. Book your consultation today!

FAQs on IVF Genetic Testing

1. Is PGD only for couples who have genetic disorders in the family?

Yes. PGD, now called PGT-M, is helpful to screen embryos for specific genetic mutations when one or both partners are known carriers. It prevents passing on serious inherited disorders to the baby.

2. Can PGS help if you’ve had previous pregnancy failures?

Yes, PGS, now called PGT-A, benefits in such cases. It checks for chromosomal abnormalities that may remain as the hidden reason behind implantation failure or recurrent pregnancy loss, even in people without a known genetic history.

3. Is genetic testing safe for embryos?

Yes, it is safe when trained embryologists perform it using advanced techniques, the embryo biopsy for PGD or PGS is safe. It’s usually carried out at the blastocyst stage, where specialists take a few cells of the embryo without any harm to the embryo’s development potential.

4. Does genetic testing guarantee a healthy baby?

No test can offer absolute guarantee, but PGD and PGS greatly minimize the risk of inherited genetic disorders and chromosomal issues. They majorly increase your chances of a successful pregnancy and a healthy baby, especially when blended with expert IVF care.

5. Can I opt for PGD or PGS in a donor egg or sperm IVF cycle?

Yes, genetic testing can come handy even when you’re using donor gametes, especially if there’s unclear genetic history available or if you simply want to ensure chromosomal normalcy before embryo transfer.