PGT-A for IVF: What Genetic Embryo Testing Can Tell You—and When Surrogacy May Be the Next Step

What Does PGT-A Actually Tell You?

PGT-A tells you whether the cells sampled from an embryo appear to have the expected number of chromosomes.

It doesn’t provide a complete assessment of embryo quality or predict exactly what will happen after transfer.

A PGT-A result does not independently determine:

PGT-A and embryo grading measure different things.

PGT-A looks at chromosome number in the sampled cells. Embryo grading evaluates features such as the embryo’s development and appearance under a microscope.

A highly graded embryo can be aneuploid, and a euploid embryo can still fail to implant.

Some results aren’t simply euploid or aneuploid. A mosaic result means the tested sample contains a mixture of cells with different chromosome findings.

Because the biopsy samples only a small portion of the embryo, PGT-A can produce results that require further clinical interpretation, particularly for mosaic or inconclusive findings. Understanding the risks and benefits of testing can help you put these results in context before making transfer decisions.

PGT-A is a screening test rather than a substitute for prenatal testing. If pregnancy occurs, your medical team may still recommend prenatal screening or diagnostic testing based on your circumstances.

Who Should Consider PGT-A?

You may want to consider PGT-A when knowing an embryo’s chromosome status could meaningfully change embryo selection or your IVF treatment plan.

Fertility specialists commonly discuss PGT-A in situations such as:

• Advanced maternal age
• Recurrent pregnancy loss
• Previous unsuccessful fertility treatment
• Cases where identifying aneuploid embryos could affect which embryo is transferred

Age can be especially relevant because the likelihood of embryo aneuploidy increases with egg age.

For some patients, PGT-A for IVF can help identify euploid embryos before transfer and avoid transferring embryos identified as aneuploid.

Cleveland Clinic’s overview of preimplantation genetic testing options provides additional context on when different forms of PGT may be considered.

There are tradeoffs to weigh as well:

• Additional testing costs
• The need for an embryo biopsy
• The possibility of mosaic or inconclusive findings
• The number of blastocysts available to test
• Whether the results would actually change your treatment plan

Whether PGT-A is worth the additional cost and testing depends largely on what the result could change in your treatment plan.

Your fertility specialist can explain how your age, previous transfers, miscarriage history and number of available blastocysts affect that decision.

Does PGT-A Improve IVF Success Rates?

PGT-A can improve embryo selection for some patients, but it doesn’t increase every measure of IVF success for every patient.

One distinction matters when interpreting success rates: success per embryo transfer and cumulative live birth from an egg retrieval are different outcomes.

A large U.S. database study examined cumulative live birth after egg retrieval among good-prognosis patients. Its results differed by age and treatment circumstances rather than showing a universal benefit from PGT-A.

The study found:

 

For intended parents, the useful distinction is between making individual transfers more selective and increasing the chance of a live birth from an entire retrieval. PGT-A can help avoid transferring embryos identified as aneuploid and may reduce unsuccessful transfers or miscarriages for some patients.

That doesn’t mean testing increases cumulative live birth for every patient who undergoes IVF.

Embryo grading adds different information. Grading assesses an embryo’s development and appearance, while PGT-A evaluates chromosome number in the biopsied cells.

Fertility clinics can consider both when prioritizing embryos for transfer.

Neither can tell you with certainty whether implantation will occur. If well-graded euploid embryos repeatedly fail, the discussion may need to expand beyond embryo selection.

PGT-A vs. PGT-M vs. PGT-SR

PGT-A, PGT-M and PGT-SR are different forms of preimplantation genetic testing that answer different genetic questions:

• PGT-A looks for aneuploidy, meaning extra or missing chromosomes.
• PGT-M may be used when there is a known genetic variant associated with an inherited single-gene condition such as cystic fibrosis.
• PGT-SR may be appropriate when a chromosome translocation, inversion or another structural rearrangement is known to be present.

PGT-M often requires preparation specific to the genetic condition being tested.

That work may begin before the IVF cycle and can involve DNA samples from the egg and sperm sources and, in some circumstances, other family members.

This comparison of PGT testing explains how each test addresses a different genetic concern.

If your embryos have already been tested, ask for the actual genetic testing report rather than relying on the description “PGT tested.”

Knowing whether your embryos had PGT-A, PGT-M, PGT-SR or a combination can help your fertility clinic interpret what information is already available before another transfer or a possible surrogacy journey.

Why Can a Euploid (PGT-A Normal) Embryo Still Fail?

A euploid embryo can still fail because PGT-A measures chromosome number in the sampled cells, not every factor involved in implantation.

Successful implantation also depends on the embryo’s continued development, the uterus, the endometrium, the transfer itself and other biological factors.

Depending on your medical history, your fertility specialist may evaluate:

• Uterine abnormalities such as polyps or fibroids that affect the uterine cavity
• Scar tissue inside the uterus
• Adenomyosis
• Endometriosis
• Endometrial factors and transfer timing
• Hormonal or other medical conditions
• Embryo development beyond what PGT-A measures
• How the embryo survives and develops after thawing
• Embryology laboratory or embryo-transfer variables
• Causes that remain unexplained after evaluation

Some proposed explanations for recurrent implantation failure, including certain immune mechanisms and tests intended to assess endometrial receptivity, remain areas of research.

Their role and the value of specific tests or treatments aren’t settled, so your fertility specialist will need to consider them in the context of your medical history.

A 2025 systematic review and meta-analysis identified embryo euploidy as a major determinant of implantation. It also found that extraembryonic factors contribute to implantation outcomes, although their incidence was comparatively low in the evidence reviewed.

The implantation failure research review identified areas including diagnostic hysteroscopy and endometrial receptivity for further study.

A euploid result narrows one major source of uncertainty without identifying why a particular transfer failed.

One failed euploid transfer may still be chance.

When failures repeat, your fertility specialist has more reason to review whether uterine, medical, transfer-related or other factors deserve closer attention.

When Repeated Failed Transfers May Point Beyond the Embryo

Repeated transfers of euploid or otherwise appropriately selected embryos can give your fertility specialist reason to investigate factors beyond embryo chromosome number before recommending another retrieval.

If usable embryos remain in storage, the next question may be whether something else is limiting implantation or pregnancy.

Your fertility specialist may revisit factors such as:

Understanding why carrying can remain difficult can also help you distinguish problems with creating embryos from problems that may affect carrying a pregnancy.

The distinction becomes especially relevant when you already have euploid embryos.

Another retrieval may increase the number of embryos available, but it won’t address a uterine condition or a medical reason that makes carrying a pregnancy unsuccessful or unsafe.

At that point, the decision may shift from whether you need more embryos to whether carrying the pregnancy is the problem that now needs to be addressed.

The answer may still support another transfer or additional treatment. If your fertility specialist believes carrying is the primary barrier, gestational surrogacy becomes a different path to consider using embryos you’ve already created.