The PGTA test in surrogacy reveals the genetics of the embryo and improves embryo transfer

It is key to understand why the PGTA test is gaining prominence when we talk about embryo transfer and the analysis of embryo genetics in the context of surrogacy.

In this article, we’ll explain what the PGTA test is, how it relates to surrogacy, why it’s important for understanding the embryo’s genetics before pregnancy, and what couples or individuals considering surrogacy should keep in mind. We’ll also discuss embryo transfer, when this type of test is appropriate, its benefits and limitations, and frequently asked questions from prospective parents. Let’s get started.

Why is surrogacy linked to the genetics of the embryo?

During a surrogacy process, in vitro fertilization (IVF) is often performed , creating embryos in a laboratory, followed by an embryo transfer to the surrogate’s uterus.
The eggs can be from the intended mother or a donor, just as the sperm can be from the intended father or a donor, or even from a donor embryo. In this context, the embryo’s genetics (i.e., its chromosome set and genetic health) plays a crucial role, as both intended parents want to maximize the likelihood of a successful, healthy, and uncomplicated pregnancy.

This is where the PGTA test comes in: since in surrogacy there is often a desire to optimize the entire process (because it involves coordination, logistics, costs and time), knowing as soon as possible if an embryo has good genetics can be very helpful.

What exactly is the PGTA test?

The PGTA test ( Preimplantation Genetic Testing for Aneuploidies ) is a genetic test performed on an embryo before implantation, with the aim of detecting abnormalities in the number of chromosomes ( aneuploidies ).

euploid ) embryo has 46 chromosomes, 23 pairs. If it has fewer or more chromosomes ( aneuploidy ), it has a higher probability of not implanting , causing a miscarriage, or leading to the transfer of an embryo with complications.

Therefore, the PGTA test allows the genetics of the embryo to be seen in advance, which helps to optimize embryo transfer.

How is the PGTA test performed?

In vitro fertilization is performed and the embryos are cultured until they reach a suitable state (usually day 5 or 6, blastocyst stage ).
A few cells are extracted from the embryo (biopsy). For example, cells from the trophectoderm .
These cells are analyzed in the laboratory using techniques such as next-generation sequencing (NGS) to check all chromosomes (24 chromosomes in some systems) and detect aneuploidies .
Based on the results, the medical team can decide which embryo is “best” for embryo transfer . If the embryo appears euploid (normal), it is transferred; if not, it may be discarded or used with caution, depending on the case.

What limitations does it have?

Although the PGTA test offers advantages, it also has certain limitations that should be understood:

It does not guarantee 100% that the selected embryo will result in a healthy baby, it only improves the odds.
It is based on the biopsy of a few cells, which may not represent the entire embryo (due to mosaicism ).
It is a selection tool, not a “correction” tool for embryos with genetic disease.
It has an additional cost and adds complexity to the assisted reproduction process, including surrogacy.

Why is the PGTA test especially relevant in surrogacy?

When planning a pregnancy through surrogacy, each phase—ovarian stimulation, embryo creation, selection, embryo transfer, and pregnancy—involves more complex costs, timelines, and logistics than a conventional pregnancy. Therefore:

Optimizing embryo transfer : By using the PGTA test to analyze embryo genetics, the embryo with the highest probability of successful implantation can be selected, potentially reducing the need for multiple transfers. For surrogacy processes, this translates to less downtime, lower costs, and less stress for everyone involved.
Higher probability of success on the first try : By choosing a euploid embryo , the chances of that embryo resulting in a pregnancy and live birth are greater. This is key when using surrogacy, as it sometimes involves working with donors, surrogate mothers, and preparation that requires international coordination.
Transparency and peace of mind for prospective parents : Parents who choose surrogacy often want a high degree of certainty and to know that they have done everything possible to minimize genetic risks. The PGTA test provides an additional level of information about the embryo’s genetics before pregnancy.
Importance of single embryo transfer : In surrogacy, a single embryo transfer is often preferred to avoid the risks of multiple pregnancies. If only one embryo is transferred, its genetic quality becomes even more important. The PGTA test helps precisely in this selection process.

In summary, in surrogacy, the PGTA test allows for better planning, selection, and peace of mind regarding the genetics of the embryo before pregnancy.

When is it worthwhile to use the PGTA test in a surrogacy process?

Although the PGTA test can be applied in many cases, it won’t always be the necessary or recommended option. Here are some factors that might make it more appropriate:

Age of the oocytes: If the donor is older or if the intended mother is providing the eggs and is of advanced age, the risk of aneuploidy increases. The PGTA test then becomes more valuable.
Previous implantation failures or miscarriages: If there have already been failed IVF cycles or pregnancies that did not progress, analyzing the embryo’s genetics can provide useful information.
Limited number of embryos available for transfer: If only a few embryos are available, assessing their genetic quality before transfer improves risk management. This is common in surrogacy when working with donor embryos and the option of transferring only one embryo.
Desire for single embryo transfer: When seeking to avoid multiple pregnancy, having an embryo with good genetics is even more important.
That prospective parents are interested in knowing the genetics of the embryo to have greater peace of mind.

On the other hand, it might not be used when:

The donor is very young and the risks of aneuploidy are low.
There are many embryos available and the parents accept a “less selective” approach and are prepared for multiple transfers.
Cost and logistics: the PGTA test adds cost, and in some cases may lengthen the process.
If the parents prefer not to have any type of genetic testing done on the embryo for personal or ethical reasons.

How does the PGTA test affect embryo transfer?

Embryo transfer is the moment when the selected embryo is implanted in the uterus of the surrogate mother (in the case of surrogacy) or the recipient mother. The embryo’s genetics have a direct impact on this step. Let’s see how:

Embryo selection for transfer : Thanks to the PGTA test, the medical team can select the embryo with the highest probability of success, based on whether its chromosomes are in order ( euploid ). This improves embryo transfer planning.
Improved implantation rate and reduced miscarriage : Euploid embryos have a better chance of successful implantation and a lower risk of miscarriage. The PGTA test helps identify these embryos.
Fewer failed transfers : In surrogacy processes, each transfer is complex. Avoiding failed transfers helps optimize time and costs.
Planning the surrogate’s cycle : If it is known in advance which embryo will be transferred with good genetics, the surrogate’s cycle, preparation of the uterus, etc. can be better coordinated.
Freezing and future transfer : Sometimes embryos are selected using the PGTA test and then frozen for future transfer when conditions are optimized for the surrogate.

In short, the PGTA test adds value to embryo transfer within surrogacy by increasing the predictability of the process and reducing risks.

What impact does embryonic genetics have on surrogacy and beyond?

When we talk about the genetics of an embryo, we are referring to its chromosomal composition and, in some cases, to other more advanced tests that could detect specific genetic diseases. In the context of surrogacy:

An embryo with a good genetic profile ( euploid ) increases the chances of a successful pregnancy, which is crucial in surrogacy.
Reducing the possibility of genetic abnormalities and miscarriages brings peace of mind to expectant parents in this type of process.
It can also influence the decision on how many embryos to transfer: when the genetics are good, transferring a single embryo makes sense, reducing the risk of multiple pregnancies and facilitating a safer pregnancy for the surrogate.
In some cases, intended parents may want to know the genetics of the embryo, although without intending to “select for non-medical traits”; ethics must be present.

However, it’s also fair to point out that the embryo’s genetics aren’t everything. The surrogate’s uterine environment, the quality of the eggs and sperm, the preparation of the endometrium, and many other factors also determine the success of surrogacy.

What are the benefits and precautions of using the PGTA test in surrogacy?

Benefits

Improved chances of embryo transfer implantation.
Reduction of the risk of spontaneous abortion associated with aneuploidies .
Possibility of more precise planning in the surrogacy process.
Peace of mind for future parents by learning more about the genetics of the embryo before pregnancy.
It facilitates the transfer of a single embryo, reducing the risk of multiple pregnancies for the pregnant woman.

Precautions and considerations

The PGTA test does not guarantee a successful pregnancy or a baby completely free of genetic complications. It is an optimization tool , not an absolute guarantee.
There is a risk of discarding embryos that could have resulted in a healthy baby, due to mosaicism or other limitations of the biopsy. Some studies indicate that the effectiveness may not be as high in all cases.
The cost and logistics of the PGTA test can increase the budget of the surrogacy process.
It is important to have genetic counseling and understand the test results, as not all results are “black or white”.
Ethical considerations: although the test focuses on the genetics of the embryo, its use for non-medical purposes must be avoided (for example, selection of aesthetic traits or sex outside of medical criteria).
Coordination between the assisted reproduction team, the genetic laboratory, the surrogate mother, and the intended parents is more complex when the PGTA test is added.

How to interpret the results of the PGTA test for embryo genetics in a surrogacy process?

When the PGTA test is performed, the results are typically presented as:

Euploid embryo : correct number of chromosomes → best candidate for embryo transfer.
Aneuploid embryo : incorrect number of chromosomes → higher risk of failure, miscarriage or complications.
Mosaic embryo: some cells have correct chromosomes, others do not → interpret with caution.

When interpreting these results for surrogacy:

euploid embryo is identified : embryo transfer is planned with greater confidence.
aneuploid embryos , you can decide to wait, create more embryos, or opt for different donation options.
In the case of mosaic embryos, some centers offer them as an option, with genetic counseling and risk assessment.
The parents and the medical team should discuss the success rates, potential risks, and implications of the embryo transfer decision.
In a surrogacy context, it is also important to coordinate with the surrogate mother, ensure that her cycle is ready, and that the embryo transfer is at the right time.

Books and articles from specialized clinics indicate that, although the PGTA test improves selection, it does not replace other factors that are fundamental to the success of pregnancy.

What are the costs, timelines, and logistics involved when integrating the PGTA test into surrogacy?

Although the specific costs vary depending on the country, clinic, and surrogacy agreement, the following should be taken into account:

Additional time: Genetic analysis of the embryo must be awaited after the biopsy, which may lengthen the time before embryo transfer.
Additional cost: The genetic test has an extra cost compared to a standard embryo transfer. Intended parents should inquire about this and factor it into their overall surrogacy budget.
Clinical coordination: In surrogacy, the following must be coordinated: egg donation or the intended mother’s own eggs/sperm, embryo creation, genetic testing, freezing if necessary, embryo transfer, the surrogate’s cycle, etc. Each step must be aligned.
Laboratory quality: It is important that the laboratory performing the PGTA test has experience, good published results, and that the assisted reproduction team has a clear protocol for embryo transfer based on the genetic test.
Embryo freezing: Many embryos that pass the PGTA test are frozen (vitrification) until the surrogate is ready for embryo transfer.
Surrogacy contract: Legal agreements must address these additional aspects – for example, what happens if there are no euploid embryos, or if the embryo transfer is unsuccessful.

For intended parents, understanding these elements is key before deciding to incorporate the PGTA test into their surrogacy process.

Specific ethical considerations of surrogacy, the PGTA test, and embryo genetics

When we combine surrogacy , the PGTA test , and embryo genetic analysis , certain ethical aspects arise that deserve to be considered:

Selection versus cure: The PGTA test selects the embryo with the best genetics, but it does not “correct” genetic problems. It is important that both intended parents and the clinic understand this.
Transparency and consent: Parents should receive comprehensive genetic counseling. They should understand what is being evaluated, the likelihood of an embryo being discarded, and the implications for embryo transfer.
Reasonable use: Using the PGTA test to prevent serious illnesses is ethically supported. However, using it to select for non-medical characteristics (e.g., sex preference when there is no medical indication) can be controversial.
Surrogate’s rights: In surrogacy, the surrogate is a key person. Her health, well-being, and informed consent must be fully respected, including in embryo transfer protocols and genetic testing of the embryo.
Accessibility and equity: The PGTA test adds cost. It is important for intended parents to consider that not everyone will have equal access, and that this can lead to inequalities in assisted reproduction.
Uncertain results: Because the PGTA test does not guarantee success, it is essential that parents do not see it as “the guaranteed solution.” The medical team must communicate this clearly.

Adopting a responsible ethical stance is essential for surrogacy, embryo transfer, and embryo selection through embryo genetic analysis to function as effectively as possible.

Cases and scientific evidence on the PGTA test in surrogacy and assisted reproduction

Although most studies are not specifically focused on surrogacy, information can be gleaned from assisted reproduction in general:

According to the Human Fertilisation and Embryology website Authority (HFEA), the PGTA test is an “add -on ” that analyzes IVF-created embryos to detect aneuploidies before implantation.
An article from the IvySurrogacy clinic indicates that the PGTA test, in the context of surrogacy or IVF, can identify embryos with a higher probability of implantation, although “it is not for everyone” and does not completely eliminate the risk of miscarriage or complications.
Another specialized site, Igenomix , indicates that its PGT-A technology using NGS allows the analysis of all 24 chromosomes, increasing the probability of success in embryo transfer by selecting euploid embryos.

These data reinforce that the PGTA test offers a real benefit, especially when the embryo’s genetics are critical for decision-making and planning, as occurs in surrogacy.

How should intended parents prepare to integrate the PGTA test into their surrogacy process?

Here is a list of recommended steps for parents considering surrogacy who wish to analyze the embryo’s genetics using PGTA testing:

Consult with an assisted reproduction specialist who has experience in surrogacy, embryo transfer, and genetic testing of the embryo.
Genetic counseling : Intended parents should speak with a genetic counselor to understand what the PGTA test examines, what the results mean, and what happens if the result is unfavorable.
Egg and sperm selection : determining whether eggs from the future mother or a donor will be used, sperm from the future father or a donor, and how this influences the genetics of the embryo.
Creating embryos in the laboratory : the laboratory must culture the embryos to the blastocyst stage , perform the biopsy and request the PGTA test to analyze the genetics of the embryo.
Freezing and planning of surrogacy : after the genetic analysis of the embryo, planning when and how the transfer of embryos to the uterus of the surrogate will be done.
Selection based on results : If one or more embryos are euploid, choose which one will be transferred. If none are, consider options such as creating more embryos or replacing oocytes, etc.
Surrogacy contract that considers scenarios : including what happens if there are no euploid embryos, timeframes, additional costs, etc.
Emotional support : both the intended parents and the surrogate mother should have psychological support, given that the genetics of the embryo and the embryo transfer involve stress and important decisions.
Embryo transfer and follow-up : once the selected embryo has been transferred, follow-up of the pregnancy, medical check-ups, etc., as in any pregnancy process.
Review of expectations and communication : parents must understand that, even if everything optimal has been done (surrogacy + PGTA test + embryo selection), some uncertainty still exists.

With these steps, intended parents can successfully incorporate the PGTA test into their surrogacy process, taking advantage of the improved selection of embryo genetics, optimizing embryo transfer, and reducing risks.

Final summary: What should we understand about surrogacy, the PGTA test, and embryo genetics?

To conclude this article clearly:

Surrogacy is an assisted pregnancy option where a surrogate carries the fetus for another person or couple, and in many cases involves in vitro fertilization and embryo transfer.
The genetics of the embryo is a very important factor in this context, because it influences implantation, pregnancy, and the baby’s health.
The PGTA test allows for the analysis of an embryo’s genetics before pregnancy, verifying that the chromosomes are complete ( euploid ) or indicating aneuploidies . This allows for improved embryo selection for embryo transfer.
In surrogacy processes, the PGTA test provides added value: it allows for the optimization of embryo transfer, the pursuit of a successful pregnancy with fewer cycles, a reduction in the risk of miscarriages, and greater peace of mind for intended parents.
However, the PGTA test does not guarantee absolute success, has a cost, and requires good coordination, genetic counseling, and ethical compliance.
Prospective parents should assess whether incorporating the PGTA test into their surrogacy process is appropriate, taking into account age, number of embryos, budget, objectives, and tolerated risk.
Finally, having realistic expectations, understanding the process, and good medical and emotional support will make the whole journey smoother.

Frequently Asked Questions ( FAQs ) about the PGTA test, surrogacy, and embryo genetics

Does the PGTA test guarantee that the baby will be born healthy?

No. The PGTA test improves embryo selection based on chromosomes, which reduces certain risks, but it does not eliminate all possible genetic or pregnancy complications. It is a helpful tool, not a guarantee.

When is the PGTA test performed in surrogacy?

It is performed after embryo creation in the laboratory (IVF) and before embryo transfer. Once the embryos reach the blastocyst stage , a biopsy is taken and the embryo’s genetics are analyzed.

How many embryos do you need to use the PGTA test?

There’s no strict minimum number, but the more embryos you have, the greater the chance that at least one will be euploid . If you only have one or two embryos, the test is still useful, but the risk of not obtaining a viable embryo is higher.

What is the additional cost of the PGTA test in surrogacy?

It depends on the country, the clinic, and the laboratory. Intended parents are advised to request a cost breakdown. However, it should be considered as part of the surrogacy budget, along with fertilization, embryo transfer, surrogate, medical care, etc.

If an embryo is aneuploid , is it automatically discarded?

In many protocols, it is discarded, but it depends on the center and the genetic counseling. In some cases, mosaic embryos with certain percentages of normal cells can be transferred, after informing the patient of the risks.

euploid embryo mean that multiple embryos must be transferred to ensure pregnancy?

Not necessarily. The purpose of the PGTA test is to allow for a single embryo transfer with a good chance of success. In surrogacy, this is an advantage because it reduces the risk of multiple pregnancies.

Does the PGTA test replace other genetic or medical checkups in surrogacy?

No. It’s a complement. Other checkups are necessary: the surrogate’s health, the quality of the receptive uterus, prenatal care, etc. The embryo’s genetics are an important factor, but not the only one.

November 11, 2025