Ensuring Healthy Beginnings: The Power of Preimplantation Genetic Screening

Ensuring Healthy Beginnings: The Power of Preimplantation Genetic Screening

The journey to parenthood is one filled with anticipation, love, and, often, anxiety. For couples undergoing fertility treatments like in vitro fertilization (IVF), the road can be even more emotionally and physically challenging. One of the most groundbreaking advancements in reproductive medicine that offers hope and reassurance is Preimplantation Genetic Screening (PGS), now more accurately known as Preimplantation Genetic Testing for Aneuploidies (PGT-A).

This powerful tool allows fertility specialists to examine embryos for chromosomal abnormalities before implantation, increasing the chances of a successful pregnancy and reducing the risk of genetic disorders. This article will explore how PGS works, its benefits, who it best suits, and how it ensures healthy beginnings for future families.

What is Preimplantation Genetic Screening?

Preimplantation Genetic Screening is a laboratory procedure used during IVF to test embryos for abnormal chromosome numbers. A typical human embryo should have 46 chromosomes—23 from each parent. Suppose an embryo has too many or too few chromosomes (a condition known as aneuploidy). In that case, it can lead to failed implantation, miscarriage, or genetic conditions such as Down syndrome, Turner syndrome, or Klinefelter syndrome.

With PGS, a few cells are safely removed from an embryo on day 5 or 6 (blastocyst stage) and analyzed for chromosomal abnormalities before the embryo is implanted into the uterus. Only those embryos with the correct number of chromosomes are selected for transfer.

Why Chromosomal Normalcy Matters

Chromosomal abnormalities are one of the most common causes of IVF failure. Even embryos that appear healthy under a microscope can carry genetic errors. These abnormalities are widespread in women over 35, as egg quality declines with age.

By identifying chromosomally normal embryos, PGS improves the chances of a healthy pregnancy and reduces the emotional and financial toll of repeated IVF cycles. This scientific insight empowers couples with the knowledge to make informed decisions about their fertility journey.

The PGS Procedure: Step by Step

1. IVF and Embryo Development: The first step involves stimulating the ovaries to produce multiple eggs, retrieving them, and fertilizing them with sperm in the lab.
2. Embryo Culture: Embryos are cultured for 5–6 days until they reach the blastocyst stage.
3. Embryo Biopsy: A small number of cells (typically 5–10) are gently removed from the outer layer of the blastocyst, which becomes the placenta. This biopsy does not harm the embryo.
4. Genetic Analysis: The biopsied cells are sent to a genetic lab, where their chromosomal makeup is analyzed using techniques like Next-Generation Sequencing (NGS).
5. Embryo Freezing: While the results are being processed (which can take 5–10 days), all embryos are cryopreserved (frozen) safely.
6. Embryo Transfer: Only the embryos confirmed to be chromosomally normal are thawed and transferred to the uterus in a later cycle.

Who Can Benefit from PGS?

PGS is particularly beneficial for:

• Women over 35 years old: As maternal age increases, so does the risk of chromosomal abnormalities.
• Couples with recurrent IVF failure: PGS helps identify embryos most likely to implant successfully.
• Couples with recurrent miscarriages: Many miscarriages are due to aneuploid embryos.
• Couples seeking single embryo transfer (SET): PGS allows for more accurate SET, reducing the risk of multiple pregnancies.
• Those with a history of genetic disorders: Although PGS does not test for specific inherited diseases (that's the role of PGD – Preimplantation Genetic Diagnosis), it ensures the embryo has the correct number of chromosomes.

Key Benefits of Preimplantation Genetic Screening

1. Improved IVF Success Rates
2. PGS increases the likelihood of implantation, clinical pregnancy, and live birth per embryo transfer.
3. Lower Miscarriage Rates
4. Since chromosomal abnormalities are a significant cause of early pregnancy loss, transferring only normal embryos reduces the risk of miscarriage.
5. Healthier Babies
6. Screening reduces the risk of chromosomal disorders, ensuring a better chance of a healthy birth.
7. Fewer IVF Cycles Needed
8. Couples often avoid multiple unsuccessful cycles by selecting the best embryos from the start.
9. More Confidence in Single Embryo Transfer
10. PGS supports SET, reducing the chances of complications associated with twin or triplet pregnancies.
11. Emotional and Financial Relief
12. While PGS adds cost to an IVF cycle, it often results in fewer overall treatments, reducing both emotional stress and financial burden in the long run.

Limitations and Considerations

While PGS offers many benefits, it’s essential to understand its limitations:

• Not a guarantee: PGS improves success rates but doesn’t guarantee pregnancy.
• Embryo freezing required: A frozen embryo transfer is typically needed since results take time.
• Cost: PGS can add ₹100,000–₹200,000 to the cost of IVF, which may concern some couples.
• Ethical considerations: Some may have moral or religious concerns about discarding abnormal embryos.
• Not suitable for all: Younger women with high-quality embryos may not always benefit from PGS unless there's a specific medical reason.

PGS vs PGD: What’s the Difference?

It’s important to differentiate between Preimplantation Genetic Screening (PGS) and Preimplantation Genetic Diagnosis (PGD).

• PGS/PGT-A: Screens for chromosomal number abnormalities (aneuploidy).
• PGD/PGT-M: Tests for specific inherited genetic diseases (like cystic fibrosis or sickle cell anemia).

Both are valuable tools but serve different purposes. Your fertility specialist can guide you on the appropriate test based on your medical history.

The Future of Fertility with Genetic Screening

As genetic science advances, the role of preimplantation testing in reproductive medicine is only set to grow. PGS is already helping thousands of couples worldwide to achieve their dream of having healthy babies. As technology becomes more precise, accessible, and affordable, it is expected to become a routine part of IVF for many patients.

Conclusion

Ensuring healthy beginnings starts with informed choices. Preimplantation Genetic Screening is a powerful way to reduce uncertainty and enhance the chances of successful, healthy pregnancies. For couples navigating the complexities of IVF, it offers a beacon of hope rooted in the precision of science.

By identifying the healthiest embryos before implantation, PGS improves outcomes and eases the emotional journey to parenthood. As always, consultation with a trusted fertility specialist is essential to determine whether PGS is the right step in your unique journey to creating a family