Preimplantation Genetic Testing (PGT): What It Is, Who Should Consider It, and What to Expect

What Is PGT, and Why Might You Consider It?

Preimplantation Genetic Testing (PGT) is a procedure that screens embryos for certain genetic abnormalities before they're transferred into your uterus. During an IVF cycle, your eggs are fertilized in the lab. After about five to six days of development, when your embryos reach a stage called the blastocyst, a few cells are removed from each embryo and sent to a genetic laboratory for analysis. The rest of the embryo continues developing and is then frozen while you wait for results.

PGT provides a snapshot of your embryo's genetics at a specific moment in time. It can help identify chromosomal issues and specific genetic defects. But… PGT doesn't guarantee a healthy pregnancy or baby. It's one tool among many in your fertility treatment toolkit.

There are also psychological considerations. For some people, getting genetic information about embryos creates anxiety or difficult decisions. If you have a mosaic embryo or limited embryo numbers, you might face tough choices about whether to transfer, retest, or continue cycling. It's worth thinking about your emotional readiness for those possibilities before you start testing.

Who Is a Good Candidate for PGT?

PGT might be recommended in several situations:

If you're over 35, your risk of chromosomally abnormal embryos increases significantly with age. At 35, about 35% of embryos may have chromosomal abnormalities; by 40, that number rises to around 60%. PGT can help identify which embryos are less likely to result in early miscarriage.

If you've experienced recurrent miscarriages, especially if they were due to chromosomally abnormal pregnancies, PGT can help identify which embryos are euploid, meaning they’re chromosomally normal, so you have a higher chance of a viable pregnancy.

If you have a known genetic condition or carry a gene mutation, PGT may be used to screen for that specific condition. This is typically only relevant if both partners are carriers of a recessive condition (where a child would inherit the condition only if they received the mutation from both parents), or if one partner has a dominant genetic condition.

If you’re using a gestational carrier, many agencies and/or gestational carriers require embryos provided by intended parent(s) to be euploid.

If you’re doing IVF for sex selection, then PGT testing is required to determine the sex of the embryo prior to transfer.

Of course, some people choose PGT because they just want more information about their embryos. That's valid too. The decision is ultimately yours.

Types of PGT: Understanding the Acronyms

Like the rest of the fertility process, PGT is full of acronyms. Here's what they mean:

PGT-A (Aneuploidy Testing) screens for an abnormal number of chromosomes. Usually, humans have 23 pairs of chromosomes (46 total). Aneuploidy is when an embryo has too many or too few chromosomes. The most common aneuploidy is trisomy 21 (Down syndrome), where there are three copies of chromosome 21 instead of two. PGT-A is the most common type of PGT testing.

PGT-M (Monogenic Testing) screens for specific single-gene conditions like cystic fibrosis, sickle cell disease, or Huntington's disease. This type of testing is used when you know there's a specific genetic condition that you and/or your partner carry.

PGT-SR (Structural Rearrangement Testing) is for people who carry balanced chromosomal rearrangements—situations where chromosomal material has been rearranged but no genetic material is missing or extra. People with balanced rearrangements are usually healthy, but their embryos may inherit unbalanced versions that result in early miscarriage. PGT-SR helps identify which embryos have a normal chromosome structure. 

For this post, we're focusing on PGT-A because it's the most commonly offered and discussed option.

Understanding Your Results: What Do PGT Results Mean?

This is the part that can feel complex—and it’s where you may have to make hard decisions. When you get your PGT-A results, your embryos will be classified into categories. Here's what each one means:

Euploid (Chromosomally Normal)

A euploid embryo has the correct number of chromosomes. These embryos have the highest implantation rates and the lowest miscarriage rates. If you have euploid embryos available, these are typically the ones your doctor will recommend transferring first.

Aneuploid (Chromosomally Abnormal)

An aneuploid embryo has an abnormal number of chromosomes. This might mean an extra chromosome (trisomy) or a missing chromosome (monosomy). Most aneuploid embryos will not result in a pregnancy. Typically, they don't implant or result in early miscarriage. Some aneuploid conditions, like trisomy 21, can result in a pregnancy that continues to the birth of an affected child. In most cases, aneuploid embryos are not transferred.

Mosaic (Mixed)

A mosaic embryo has a mix of cells: some cells have the normal number of chromosomes, while others have an abnormality. The research on mosaic embryos is still evolving, and different clinics may have different recommendations. 

Some mosaic embryos result in healthy pregnancies and babies. Others do not. The reality is that we don't have perfect predictive ability for mosaic embryos yet. Some clinics will transfer mosaic embryos, especially if you don't have euploid options available. Some will not. This is an evolving area of science and medicine, and so it’s an important conversation to have with your fertility team.  Their comfort level with mosaic transfer—and the specific circumstances of your mosaic embryo—should inform any decisions.

No Result / Inconclusive

Sometimes the lab can't get a clear result, usually because there weren't enough cells to analyze or the cells didn't grow well. In these cases, you may be given the option to retest, or your doctor may recommend transfer based on morphology (how the embryo looks under the microscope) or not transferring that embryo.

Why the Cost? Understanding What You're Paying For

Estimates vary, but at between $2,000 and $6,000 per cycle for PGT can feel like a lot—especially when you're already managing significant fertility treatment costs. Here's what that money actually covers:

The biopsy itself requires specialized equipment and trained embryologists. A few cells must be carefully removed from each embryo without damaging it—this is precision work.

The genetic analysis involves sequencing or analyzing the DNA of those cells. Labs use sophisticated technology to count chromosomes and identify abnormalities. Depending on the type of testing, the analysis can be quite complex.

Logistics and expertise include the lab's quality control, validation of results, consultation with genetic counselors or doctors to interpret findings, and secure handling of genetic information.

Your peace of mind (this one's not on an invoice, but it matters). For many people, having genetic information about their embryos helps them feel more confident in their transfer decision. That can be genuinely valuable.

Does PGT-A Actually Work?

The research shows that PGT improves some fertility outcomes for some people, but it's not a guarantee.

In people over 35, PGT can significantly reduce miscarriage rates compared to not testing. PGT tends to shorten the time from when someone starts trying to become pregnant to pregnancy, and to increase live birth rates for those in this age group.

However—and this is important—euploid embryos don't always result in pregnancy, and aneuploid embryos don't always fail. Biology is complicated.

For people under 35 without specific risk factors, the benefit of PGT is minimal. Your embryos are more likely to be chromosomally normal already, so PGT does not improve live birth rates, but does reduce the already-low miscarriage rate.

One thing PGT doesn't do: it doesn't improve your egg or sperm quality. If your issue is low egg and/or low sperm quality, PGT might identify abnormal embryos, but it won't create more normal ones. In that case, the focus might be on optimizing your protocol, considering additional cycles, or exploring other options with your team.

Is PGT Safe? Understanding the Risks

Short answer: PGT is considered safe, but like any procedure, it carries small risks.

The biopsy itself—removing those few cells—does carry a small risk of damaging the embryo. In experienced hands, this risk is minimal. Studies have not shown higher miscarriage rates or developmental problems in babies born after PGT compared to babies born after IVF without PGT.

Do You Need Genetic Counseling?

Probably. While it depends on what you're testing for and your personal situation, most clinics recommend counseling when people do genetic testing.

You should definitely have genetic counseling if:

• You're considering PGT-M or PGT-SR
• You have a known family history of a genetic condition
• You and your partner are known carriers of the same genetic mutation
• You're considering PGT after multiple miscarriages and want to understand possible genetic causes
• You're trying to decide whether to transfer a mosaic embryo

In these situations, a genetic counselor can help you understand your specific risk, what the results mean for you, what your options are, and how to think through the decision.

It may be optional but helpful if:

• You're doing PGT-A (aneuploidy testing) and want help interpreting results
• You want to discuss the emotional and psychological aspects of testing and results

Many fertility clinics include genetic counseling as part of the PGT process. While some clinics make it optional, we recommend asking if it's available and taking advantage of it.

Timeline and Logistics: How Long Does This Take?

Biopsy: Day 5 or 6 of embryo development (at the blastocyst stage). This is when your embryos are ready to be biopsied. Samples need to go to the lab for testing, so you won't transfer during this cycle.

Lab turnaround: 7-14 days for PGT-A and PGT-SR, though some labs offer expedited results in 3-5 days (usually for an additional fee). The variation depends on the lab's workload and whether you're using standard or expedited processing. PGT-MT can often take longer.

Embryo transfer: Typically during your next menstrual cycle. This gives you time to understand your results, discuss them with your doctor, and plan your transfer. If you don’t have any euploid embryos, you might choose to do another retrieval cycle.

Total timeline: From egg retrieval to having results and planning transfer is typically 2-4 weeks, depending on how fast your lab is and on your cycle.

So, is PGT Right for You?

As with so much about the fertility journey, deciding whether to do PGT is personal. Here are some questions to help think through it:

• Where are you in your fertility journey? If you're under 35 with no risk factors and this is your first IVF cycle, PGT is unlikely to benefit you. If you're over 35 or have had multiple miscarriages, the information might feel more valuable.
  
  
• What's your financial situation? Can you afford PGT without stretching yourself thin? Remember that fertility treatment already costs a lot, and adding PGT is a real financial decision.
  
  
• What's your comfort with uncertainty? Some people want as much information as possible before transferring. Others find too much information paralyzing. Both are valid approaches.
  
  
• What does your doctor recommend? Your fertility team knows your specific situation and can give you personalized advice.
  
  
• How would you feel about different results? If you got results showing only aneuploid embryos, would you want to know? Thinking through these scenarios can help you decide if testing is right for you.
  
  

PGT isn't a magic solution, but it does offer valuable information that can help guide decision making and improve odds of a healthy pregnancy.

Your fertility journey is uniquely yours. Whatever you decide, make sure it's a decision that feels right for you, informed by your doctor, and made with clarity about what testing can and can't do.

At Sunfish, we help guide and support you throughout your journey, providing resources built with our medical advisory team for every step, from getting started through your treatment cycle. If you're thinking about PGT as part of your IVF treatment and want to understand your financial options, we're here to help you explore personalized funding solutions that work for your specific treatment plan.

Have specific questions about PGT or other fertility treatments? Your fertility clinic or a genetic counselor can provide personalized guidance for your situation.