When you’re building your family through IVF, there’s so much riding on the health and potential of each embryo. While the uncertainty may feel overwhelming, today’s advancements in genetic testing for IVF can give you insight and clarity into the health of your embryos.

Preimplantation genetic testing (PGT) allows intended parents to screen embryos for genetic abnormalities, helping them take proactive steps toward a healthy pregnancy.

As part of our work safely transporting cryopreserved embryos, we’ve seen firsthand how significant this decision can be for intended parents. Choosing whether to pursue PGT is a common step in the IVF journey, one that often comes with important questions, careful considerations, and a wide range of emotions.

This blog will help you understand PGT, when it might be recommended, and how it fits into the IVF process – so you can feel informed and prepared to make the best decision for your family.

Understanding the Types of Preimplantation Genetic Testing

PGT is a specialized procedure used during IVF to screen embryos for genetic or chromosomal abnormalities. Carried out by experienced embryologists and genetic specialists, PGT helps identify the embryos with the best chances of resulting in a healthy pregnancy.

There are three main types of preimplantation genetic testing for IVF, each addressing different concerns:

PGT-A (Aneuploidy Screening)

PGT-A checks whether embryos have the correct number of chromosomes. A healthy embryo should have 46 chromosomes arranged in 23 pairs. Extra or missing chromosomes (a condition called aneuploidy) can lead to genetic disorders like Down syndrome, Edwards’ syndrome, or Turner syndrome.

Aneuploidy is one of the most common causes of failed implantation and miscarriage. PGT-A increases the chances of selecting a chromosomally normal embryo, improving both implantation success and pregnancy outcomes.

PGT-M (Monogenic Disorder Testing)

PGT-M screens embryos for specific inherited genetic mutations. This type of testing is often used by families with a known history of conditions like cystic fibrosis, sickle cell anemia, muscular dystrophy, Huntington’s disease, and other common disorders.

By using PGT-M, intended parents can increase the chances of a healthy pregnancy and reduce the risk of passing on serious genetic conditions to their children.

PGT-SR (Structural Rearrangement Testing)

PGT-SR looks for abnormalities in chromosome structure, such as missing or extra pieces or segments that are out of order. These types of abnormalities, called structural rearrangements, can increase the risk of miscarriage or cause developmental problems in the child. 

Intended parents with a history of structural rearrangements are at a higher risk of producing embryos with an unbalanced number of chromosomes. PGT-SR helps identify embryos with balanced chromosomal structures, improving the chances of a successful pregnancy.

If you choose to pursue PGT, your fertility specialist and genetic counselor will guide you in deciding which type of embryo genetic testing is right for you.

How Is PGT Performed?

Preimplantation genetic testing for IVF is a precise process that begins once the embryo has reached the blastocyst stage of embryo development (typically day five or six after fertilization).

Here’s how it works:

1. Biopsy: Embryologists carefully remove a small sample of cells from the outer layer of the embryo that develops into the placenta. The inner cell mass, which becomes the fetus, remains untouched. 
2. Genetic Analysis: The biopsied cells are sent to a laboratory where genetic specialists analyze them based on the type of PGT being performed.
3. Freezing and Results: While awaiting results, the embryos are frozen (cryopreserved) to ensure they remain viable for future transfer. Results are typically available within a couple of weeks, although more complex testing like PGT-M may take longer. 

Once the results are in, your fertility team guides you through the next steps. They help you understand the findings and select the embryos with the highest potential for implantation and successful pregnancy.

When Is Preimplantation Genetic Testing Recommended?

PGT is not recommended for every IVF journey, but there are several situations where your fertility team may suggest it.

Candidates for PGT can include:

• Women over the age of 35 who are at greater risk of producing eggs with chromosomal abnormalities.
• Women who have experienced multiple miscarriages.
• Women who have undergone multiple unsuccessful fertility treatments.
• Women with a diagnosis of unexplained infertility.
• Intended parents who have had a previous pregnancy or child with chromosomal abnormalities.
• Intended parents or donors with a family history of genetic disorders.
• Intended parents working with a surrogacy agency that requires embryo genetic testing.

Deciding whether to pursue preimplantation genetic testing for IVF is a deeply personal choice, but it’s not one you have to make alone. With the guidance of your genetic counselor, you can explore your unique circumstances and determine if PGT is the right choice for your family.

Benefits and Considerations of PGT

Preimplantation genetic testing can offer significant advantages, but it’s also important to weigh potential challenges.

Benefits

• Better Embryo Selection: Identifies embryos with the highest potential for a healthy pregnancy. 
• Reduced Risk of Miscarriage: Screens for chromosomal abnormalities that often cause pregnancy loss. 

• Faster Path to Pregnancy: Increases the chances of success per cycle, reducing the number of cycles needed.

• Healthier Outcomes: Reduces the likelihood of transferring embryos with serious genetic conditions.

• Peace of Mind: Offers reassurance and reduces stress and uncertainty during the IVF process.

• Long-Term Cost Savings: Provides insight into which embryos are worth transferring and freezing, reducing unnecessary transfers and IVF expenses.

• Optional Gender Selection: Allows parents to select embryos of a preferred gender where legally and ethically permitted.

Considerations

• Testing Limitations: May result in false positives or negatives, and some genetic flaws may go undetected.

• No Guarantee: Reduces risks but does not eliminate all possibilities of genetic issues nor guarantee a successful pregnancy.

• Risk to Embryos: The biopsy, freezing, and thawing process carries a slight chance of damage, with around 5% of embryos being lost during PGT.¹

• Higher Costs: Adds significant expense to the IVF process, which may not be covered by insurance.

• Longer Timeline: Adds time to the IVF process, as embryos must be biopsied, frozen, and tested before transfer.

• Ethical Concerns: Raises questions about selecting embryos based on genetics or other traits.

• Emotional Challenges: Deciding which embryos to transfer or discard can be emotionally difficult for intended parents.

While these considerations are important, they don’t overshadow the fact that preimplantation genetic testing has helped countless families achieve their dreams of building a healthy family. With the guidance of your fertility team, you can weigh these factors and decide whether PGT aligns with your family-building goals.

Supporting Your Next Steps 

At CryoLogistics, we recognize how vital each step in this journey is, especially when it comes to safely transporting your precious embryos.

Our specialized hand-carry cryogenic transport services ensure your embryos are handled with the utmost care and safety every step of the way.

With services like preimplantation genetic testing, guidance from your fertility team, and reliable cryo transport, your dreams of starting a family are in the best hands.

Learn how we can support you on your IVF journey.

Sources:

1. Preimplantation Genetic Testing (PGT)