Preimplantation genetic testing for aneuploidy has a clear role in modern IVF — but the evidence does not support testing every embryo for every patient. Here is what the international guidelines say, and how we approach the question at HOPE. PGT-A involves removing a small number of cells from an embryo at the blastocyst stage and analysing them with next-generation sequencing to assess the chromosome count. An embryo with the expected 46 chromosomes is termed euploid; any imbalance in chromosome number is termed aneuploid. The rationale is intuitive: if we can identify chromosomally normal embryos before transfer, we should be able to avoid transferring those destined to fail. In practice, however, PGT-A has been adopted far beyond the patient groups for whom it was originally designed. The major international professional bodies — the American Society for Reproductive Medicine (ASRM, 2024) and the European Society of Human Reproduction and Embryology (ESHRE, 2023) — have both declined to endorse routine PGT-A for the general IVF population. The right question is not "can we test the embryo?" but "will testing change the outcome for this patient?" For some patients, yes. For many, the evidence says no. “The value of PGT-A as a routine screening test for all patients undergoing IVF has not been demonstrated.” The clinical evidence draws a clear line between patients for whom PGT-A may be genuinely useful and those for whom it adds cost, time, and diagnostic uncertainty without improving the chance of taking home a baby. Aneuploidy rates rise predictably with age — and this is the single most important reason PGT-A is more useful for some patients than others. Human oocytes begin meiosis during fetal development and remain arrested for years before ovulation. Over time, the proteins that hold chromosomes together deteriorate, increasing the risk of segregation errors during division. For patients up to their late thirties, a meaningful proportion of embryos remain chromosomally normal — and expert morphological selection by experienced embryologists is well placed to identify them. The clinical case for routine PGT-A becomes substantially stronger only beyond the age of 40, when the proportion of aneuploid embryos rises sharply. Franasiak et al. (2014). Fertility & Sterility, based on analysis of over 15,000 trophectoderm biopsies. PGT-A is a powerful technology, but it carries real diagnostic and clinical limitations. A patient considering the test deserves to know all of them. From the 2024 ASRM committee opinion and current peer-reviewed evidence. Multiple multicentre randomised controlled trials have failed to demonstrate a consistent benefit of routine PGT-A on cumulative live birth rates. The biopsy result does not always reflect the embryo's true genetic status. A 2025 systematic review confirmed that diagnostic accuracy remains under active investigation. Many embryos contain a mixture of normal and abnormal cells. The biopsied trophectoderm cells may not represent the inner cell mass that becomes the fetus. In patients with few embryos, PGT-A can lead to the rejection of embryos that might have implanted — including mosaic or borderline cases now known to be capable of healthy live births. The biopsy, genetic analysis, and mandatory freeze-all strategy substantially increase the cost and duration of treatment, often without a corresponding benefit. Removing cells from an embryo is an invasive procedure. Performed well, the risk is low — but it is not zero, and it is performed on every tested embryo. Some patients consider travelling abroad specifically because PGT-A is offered as routine in other jurisdictions. The evidence — and our own outcome data — suggest the test is rarely the deciding factor. Strong IVF outcomes are the product of integrated clinical and laboratory excellence at every stage — individualised stimulation, expert oocyte assessment, rigorous embryology, and evidence-based morphological embryo selection. PGT-A is one tool among many, and the centres with the best results are not necessarily those that test the most. Across the full treatment pathway, without routine PGT-A. Compared with a European average of ~27–40% per transfer (ESHRE EIM, 2025). Achieved through individualised stimulation and PLM-guided oocyte selection. The decision should always be based on individualised clinical assessment and an honest discussion of the evidence — not on the assumption that more testing automatically means better care. If you would like to discuss whether PGT-A is right for your situation, we are happy to talk it through.
Fertility & Sterility 122(3):421–434 Two questions, two very different answers.
Patients where PGT-A has a defined clinical role
Patients for whom routine PGT-A is not supported
Why maternal age is the central factor.
The proportion of aneuploid embryos increases steadily after the age of 40.
Five limitations that rarely make the consent form.
Important Limitations
No improvement in live birth rates for the general IVF population
False positives and false negatives are real
Mosaicism makes interpretation complex
Viable embryos may be discarded
Significant added cost and time
The biopsy itself carries a small risk
Excellent IVF outcomes do not require routine PGT-A.
Our results, achieved without routine PGT-A, match or exceed centres where it is standard.
Cumulative pregnancy rate, own eggs
Pregnancy rate per frozen transfer, own eggs
Pregnancy rate per fresh transfer, own eggs
For some patients PGT-A is genuinely useful. For most, careful clinical and laboratory care matters far more.
