At some point during IVF, you’ll almost certainly hear about PGT-A, a test that screens embryos for chromosomal abnormalities before transfer. It’s an important part of many fertility conversations, but it’s only one piece of the picture.
An equally important question is what happens before an embryo ever reaches the lab. By the time an embryo exists in a dish on day five, many of the biological factors that influence its development have already been established during the weeks and months before retrieval, as the egg matured within the body. PGT-A reads that outcome. It doesn’t create it, and it can’t improve it.
So, before you get to “test or don’t test,” it’s worth asking a different question: what actually shapes egg quality for IVF, and how much of it can you influence? That’s where preparation becomes most meaningful.
What PGT-A Actually Measures (and What it Doesn’t)
PGT-A, or preimplantation genetic testing for aneuploidy, checks whether an embryo has the expected number of chromosomes. A typical human cell has 46. An embryo with too many or too few (aneuploid) is more likely to fail to implant or end in miscarriage; embryos with the expected count are called euploid.
Around day five or six, an embryologist removes a small cluster of cells from the outer layer of the blastocyst. These cells will become the placenta, not the baby, and are sent to a genetics lab while the embryos remain frozen. Although other forms of preimplantation genetic testing exist, including PGT-M for inherited single-gene conditions and PGT-SR for chromosomal rearrangements, PGT-A is the broad chromosome screening test and the one at the center of most discussions.
The distinction is important: PGT-A is a snapshot of chromosomal status. It doesn’t alter that status; it simply reports what is already present. And what it measures largely reflects the egg.
What “Egg Quality” Actually Means
Understanding egg quality starts with recognizing that it has two distinct components:
- Chromosomal normality (ploidy). Whether the egg has the expected number of chromosomes. This is heavily age-linked and is the layer PGT-A reads. It is not something a lifestyle reliably changes.
- Developmental competence. The egg’s capacity to mature, fertilize, and support early embryonic development is influenced by the hormonal and metabolic environment it develops in over the preceding weeks. This is the layer where physiological readiness matters.
So, to improve egg quality for IVF, the truth is, you can’t rewrite the chromosomal lottery, but you can influence the conditions your eggs mature in and the state your body is in going into a cycle. While chromosomal normality is largely age-related, developmental competence is influenced by the physiological environment in which an egg matures. That’s where preparation becomes meaningful.
So Much is Decided Before the Embryo Exists
One of the strongest influences on an embryo’s chromosomal status is the egg it came from, and maternal age is the most important factor affecting chromosomal normality. As we get older, the proportion of eggs with chromosomal errors rises, which is precisely why aneuploidy rates climb with maternal age and why PGT-A results skew the way they do. Seen in that context, PGT-A is measuring the chromosomal status of an embryo that has already developed. Because the embryo’s chromosomal status is heavily influenced by the egg, those results often reflect biological processes that occurred well before fertilization.
Readiness Factors You Can Actually Work On
“Physiological readiness” refers to the overall state of your body leading into IVF. It encompasses the modifiable factors that shape the environment in which eggs mature and embryos implant. While these factors cannot guarantee a particular outcome, they represent meaningful aspects of preparation that patients can actively work on.
- Stress load and cortisol. Chronically elevated stress signalling shifts hormonal balance and recovery; managing it is one of the more controllable factors in the lead-up to a cycle. There is a distinct relationship between stress and infertility.
- Sleep and recovery. Restorative sleep helps support normal hormonal rhythms and overall recovery, both of which contribute to the body’s readiness heading into treatment.
- Metabolic and hormonal balance. Supporting metabolic and hormonal health helps create an environment that supports normal follicle development.
- Cycle regularity. Consistency in the underlying rhythm can provide insight into how the body is functioning, leading to treatment.
None of these guarantees a euploid embryo, but they’re the inputs you can influence, and going into retrieval and transfer in the best condition you can reach is a goal worth taking seriously.
Where OTO Fertility Fits: Measuring Readiness, Not Predicting Outcomes
This is where OTO Fertility fits into the IVF journey. OTO is a wearable biosensor that measures and helps optimize physiological readiness for conception and IVF by tracking signals such as stress, recovery, and cyclical patterns. It doesn’t test embryos, predict treatment success, or promise a particular outcome. Instead, it gives patients continuous insight into the aspects of preparation that can be monitored and influenced before retrieval and transfer. Used alongside standard fertility care, OTO helps patients better understand how their body is trending throughout an IVF cycle and make more informed decisions about the preparation they can control.
Evidence on PGT-A, So You Have the Full Picture
If you’re weighing the test, it’s worth understanding what the current evidence says.
Where it helps
For the right patients, PGT-A can reduce failed transfers and miscarriages. A 2024 analysis found higher live birth rates per transfer with PGT-A than without (roughly 50.6% versus 35.8%) and modest cumulative benefits that grew with age. Benefits appeared modest among patients aged 35–37 and became somewhat larger among those aged 38–40. Ruling out the embryos most likely to miscarry can also shorten the path to a pregnancy and support confident single-embryo transfer.
Where the evidence is less clear
For good-prognosis patients, the case weakens. A large trial published in the New England Journal of Medicine, spanning more than 1,200 patients across 14 centers, found live births in about 77.2% of the PGT-A group versus 81.8% of the conventional-IVF group; the study did not find improved live birth outcomes with routine PGT-A. In patients under 35, cumulative live birth rates were essentially flat (roughly 67.3% versus 68.6%). And “mosaic” embryos, once routinely set aside, are increasingly transferred: 2024 research documented 488-plus healthy babies born from mosaic transfers, and ASRM now describes such transfers as a relatively safe option with low or minimal added risk. Some embryos that might previously have been considered unsuitable for transfer.
ASRM’s 2024 committee opinion reflects this, taking the position that PGT-A’s value as a routine screen for every IVF patient hasn’t been demonstrated. Yet usage has surged from about 14% of IVF cycles in 2014 to 44% in 2019. The test typically adds $4,000–$10,000 out of pocket (roughly a $2,500 biopsy plus a $2,500 lab fee). That gap between guidance and practice has drawn scrutiny, including 2025 reporting on some 700 patients in class-action suits alleging they were misled about the test’s accuracy and utility.
None of this means PGT-A lacks value. Rather, its benefits depend on the individual patient’s age, diagnosis, and treatment history.
Preparing Your Body for Embryo Transfer
Testing gets most of the attention, but transfer is its own readiness window. Even a euploid embryo requires a receptive uterine environment for implantation. While embryo chromosomes cannot be changed at this stage, aspects of physiological readiness remain relevant in the lead-up to transfer.
This is exactly the stretch where preparing your body for embryo transfer is within reach: keeping stress and cortisol in check, protecting sleep and recovery, and heading into the transfer window with your readiness signals as steady as you can make them. It won’t override an embryo’s biology, but it’s the part of transfer prep you can actually act on, and OTO is designed to make those signals visible while you do.
Questions Worth Asking Your Clinic
- Given my age and diagnosis, does PGT-A improve my cumulative live birth rate, not just the per-transfer number? The cumulative figure is the one that reflects your real odds of having a baby.
- How do you handle mosaic results? Some clinics discard them; ASRM considers transfer a reasonable option in many cases.
- If everything comes back abnormal, what are my options? Ask about retesting, mosaic policies, and second opinions.
- What’s the false-positive rate of your testing platform? No test is perfect; the margin of error shapes how you read results.
- And ask yourself: what am I doing to optimize the inputs I can influence? There are factors that stay in your control regardless of what the testing conversation decides.
The Bottom Line
PGT-A can be a valuable tool for some patients, but it is only one piece of the IVF picture. You can’t reliably change age-related chromosomal changes once they exist.
What you can do is focus on the layer that’s actually yours: the physiological readiness your body brings to the cycle. Learning how to improve egg quality for IVF begins by focusing on the aspects of preparation you can influence before retrieval. While no lifestyle change or technology can guarantee a particular outcome, supporting your body’s physiological readiness is one of the few parts of the IVF process that remains within your control. OTO is designed to make those readiness signals visible, helping you better understand your body’s patterns so you can approach treatment with greater awareness and confidence.