PGT-A / Preimplantation Genetic Testing Explained

Olga Pysana
6 hours ago
8 min read

What It Is, How It Affects Success Rates, the Ethical Debate, and What It Means for Your Surrogacy Journey

If you are planning a surrogacy journey and have started speaking with agencies and clinics, you have likely already come across the term PGT-A, PGT-M, NGS, PGD, etc.What you may have noticed is that it is not presented consistently.

Some clinics recommend it strongly. Others describe it as optional. Some do not mention it unless you ask.

For something that can influence both your timeline and expectations, that inconsistency matters. It can shape decisions before you fully understand what is involved.This is where uncertainty usually begins. Not because the process itself is unclear, but because the explanation is often incomplete or presented from a single perspective.

PGT-A is not a simple yes-or-no decision. It sits at the intersection of medical science, probability, cost, and personal values. In a surrogacy journey, especially an international one, those layers matter more than they first appear.

By the time this topic comes up, most intended parents are already deep into planning. You may be choosing a clinic, reviewing donor options, or thinking through timelines. At that point, decisions can start to feel procedural, just another step to move forward.

But this is not one of those steps.

Whether you use PGT-A or not can influence how embryos are selected, how success rates are presented to you, how many transfers you may need, and how you experience each stage of the process.

And yet, many parents make this decision based on how it is introduced to them, rather than from a complete understanding.

This is not about convincing you to use PGT-A, or discouraging it.It is about making sure you understand what it actually means in practice: what it can tell you, what it cannot, how it is used across clinics, and where the real questions begin.

Because once you understand that, the decision becomes yours in a meaningful way, not something you were guided into without realizing.

At a deeper level, this is not just a medical decision. It is a decision about how you want to navigate uncertainty in your journey.

Some parents want as much data as possible. Others are more comfortable accepting that not everything can be controlled.There is no single right approach.But there is a difference between choosing consciously and simply following a recommendation.

And that is the difference this guide is here to clarify.

What Is PGT-A?

PGT-A stands for Preimplantation Genetic Testing for Aneuploidies. It is a laboratory procedure performed on embryos created through IVF, before any embryo is transferred to a surrogate.

In practice, embryos are developed in the lab to the blastocyst stage, usually around day 5 or 6. A small number of cells is then taken from the outer layer of each embryo and sent for chromosomal analysis.

Based on that analysis, embryos are classified as:

Euploid (typical chromosome count)
Aneuploid (chromosomal abnormalities)

Clinics generally recommend transferring embryos classified as euploid.

The reasoning is straightforward. Chromosomal abnormalities are a leading cause of failed IVF cycles, early miscarriage, and certain genetic conditions. If you can identify embryos with a typical chromosomal profile before transfer, you may improve the chances of a successful pregnancy.

That logic is valid, but only to a point. As with most aspects of reproductive medicine, the reality is more nuanced than the way this is often presented.

Does PGT-A Actually Improve Success Rates?

This is where the difference between how clinics present PGT-A and what the data actually shows becomes most visible.

The research about PGT-A improving the success rates is genuinely mixed, and whether PGT-A improves outcomes depends largely on who is being tested.

Where PGT-A shows real benefit

The strongest evidence is for intended parents using their own eggs, particularly over the age of 35–37. As maternal age increases, so does the rate of chromosomal abnormalities in embryos.

In this context, PGT-A can help identify embryos that are unlikely to lead to a viable pregnancy before transfer. This can reduce the number of failed transfers, lower the risk of miscarriage, and, in many cases, shorten the overall time to a successful pregnancy.

It can also reduce the emotional and financial impact of repeated unsuccessful transfers.

Where the benefit is less clear

For younger intended parents, especially those using donor eggs from screened, healthy donors, the picture is different.

Eggs from young donors already have a low rate of chromosomal abnormalities. Multiple large studies, including randomized controlled trials, have shown that PGT-A does not significantly improve live birth rates in this group, and in some cases may even reduce them.

Important: Always ask your clinic to explain why they are recommending PGT-A in your specific case.

A good clinic will not present it as a default step. They will walk you through the reasoning based on your age, embryo source, and overall situation, and explain how the evidence applies to you, not just in general terms.

Embryo Gender Considerations in Surrogacy

For many intended parents, the gender of embryos is an important consideration when planning a surrogacy journey. This information is sometimes available from genetic testing laboratories, and knowing it can impact family planning decisions, embryo selection, and overall expectations.

Why Gender Information Matters

Family Planning: Some parents wish to balance the genders of their children or have personal preferences for a particular gender.
Medical Reasons: Certain gender-linked genetic conditions (e.g., hemophilia, Duchenne muscular dystrophy) make gender information medically relevant.
Transfer Strategy: When transferring embryos one at a time, knowing the gender can help intended parents make more informed decisions about which embryo to prioritize for transfer.

Accuracy and Limitations

Laboratory testing is highly reliable, but rare errors or mosaic embryos may affect the accuracy of gender determination.
It is important to confirm with the clinic or laboratory how gender is reported and what confidence level accompanies the results.

Legal and Ethical Considerations

Laws regarding gender selection differ by country. Some regions prohibit non-medical gender selection, while others permit it under certain circumstances.
Intended parents should always verify local regulations before making decisions based on embryo gender.
Ethical considerations should be discussed with the clinic to ensure decisions are aligned with personal values and professional guidance.

Practical Guidance for Intended Parents

Request documentation of embryo gender if it is important to your planning.
Confirm your clinic’s policy for reporting gender, since some only provide it on request.
Use gender information as one factor among many when planning your surrogacy journey, rather than as a sole decision criterion. (most providers will still recommend transferring embryos based on their quality rather than gender)

The Ethical Debate: What You Should Know

PGT-A sits at the intersection of medicine, ethics, and personal values. There is no single way to look at it, and a balanced view means understanding both perspectives.

The case in favour

For many clinics and specialists, PGT-A is a practical tool.

The argument is straightforward: if you can identify embryos that are unlikely to lead to a viable pregnancy, you can reduce failed transfers, lower the risk of miscarriage, and avoid some of the emotional and physical strain that comes with repeated cycles.

From this perspective, PGT-A is not about “selection” in a moral sense. It is about making informed decisions based on available data.

The concerns raised

At the same time, there are well-established concerns, and they are taken seriously within the reproductive medicine community.

One of them is ethical.

For those who believe embryos have moral status from the moment of fertilisation, the idea of testing and potentially discarding embryos raises difficult questions.

There are also clinical limitations to consider.

PGT-A is not infallible. A condition called mosaicism, where an embryo contains both normal and abnormal cells, can lead to uncertain or even misleading results. Some embryos classified as abnormal have gone on to result in healthy pregnancies.

There is also an ongoing discussion about how widely PGT-A is being used.

Some specialists question whether it is applied too broadly, particularly in cases where it adds cost and complexity without clear benefit.

And beyond the clinical and practical concerns, there is a wider conversation.

Some argue that genetic selection, even when used with good intentions, can reinforce harmful assumptions about people living with chromosomal conditions.

These are not fringe opinions.

They are part of an ongoing, serious discussion within the field.

You are entitled to understand them, and to take them into account when making your decision, whatever that decision ultimately is.

What This Means Specifically for Surrogacy

In a surrogacy journey, PGT-A is not just a technical step. It directly affects how your process is structured and how decisions are made along the way.

Embryo numbers and transfer strategy

After PGT-A, it is common to find that some embryos are classified as aneuploid and set aside.

If you start with a limited number of embryos, this can have a real impact on your options.

This is why it is important to understand in advance what your expected embryo numbers might look like, and how your clinic approaches embryos that are untested or classified as aneuploid. These are conversations that are better had before testing begins, not after results come in.

Single embryo transfer

A growing number of international surrogacy programs now recommend to transfer one embryo at a time.

PGT-A can support this approach by giving clinicians more confidence in embryo selection. The goal is to reduce the risk of multiple pregnancies, which carry additional medical risks for both the surrogate and the babies.

In that sense, PGT-A is often positioned as part of a risk management strategy, not just a success-rate tool.

Program requirements vary

There is no universal approach to PGT-A across countries or clinics.

Some programs recommend it routinely. Others leave the decision entirely to you.

In some cases, these recommendations are based on clinical reasoning. In others, they are influenced by internal protocols or commercial structures.

Understanding the difference requires asking direct, specific questions, and paying attention to how clearly those answers are explained.

Cost and timing

PGT-A adds both cost and time to the process.

The cost can range from several hundred to several thousand dollars, depending on the number of embryos and the laboratory used.

It also typically requires embryos to be frozen while results are processed, which can extend your timeline.

Questions to Ask Your Clinic

If your clinic recommends PGT-A, the most important step is to understand why it is being recommended in your specific case.

These are the questions that will help you evaluate that:

Why are you recommending PGT-A for us specifically? What in our profile makes it relevant?
What rate of chromosomal abnormalities do you typically see with embryos from our egg source and age group?
How does your clinic approach mosaic embryos? Are they considered for transfer or excluded?
What happens to embryos classified as aneuploid? Are they stored, discarded, or is that decision left to us?
Will PGT-A affect timing or the transfer protocol with our surrogate?
What is the total additional cost, and what exactly does it include?

If the answers are vague, overly simplified, or you feel discouraged from asking - that is something to take seriously.

The Bottom Line

PGT-A is a legitimate and, in many cases, useful tool in IVF. It can reduce the risk of failed transfers and miscarriage, particularly for intended parents using their own eggs or those with a history of chromosomal issues.

But it is not universally necessary. It is not without limitations. And it carries financial and ethical considerations that should be understood, not treated as a routine step.

What matters most is understanding why it is being recommended in your case, what the realistic benefit is, and whether you are comfortable with the decisions that come with it.

This is exactly the kind of conversation I have with intended parents every day. Because how you move through this process matters, not just the outcome.