If you have lost several pregnancies, you may have been told, or read, that IVF with embryo testing is the answer. For some people it plays a real part. For others it adds cost, procedures and disappointment without changing the outcome. This guide explains where PGT fits, where it does not, and the questions that help you tell the difference. For a general introduction to the three types of testing, see what PGT is and how it works.
What "recurrent miscarriage" means
The NHS defines recurrent miscarriage as three or more miscarriages, and says anyone in this situation should talk to a GP, who will usually refer them for tests to look for a treatable cause (NHS, reviewed 2026). Other professional bodies use different thresholds for starting investigations; Europe's fertility society, ESHRE, published an updated recurrent pregnancy loss guideline in 2023, with a version written for patients (ESHRE, 2023). If you have had fewer than three losses and are worried, it is still reasonable to ask your doctor whether investigation makes sense for you.
The NHS also offers an important piece of perspective: most women who have had a miscarriage go on to have a successful pregnancy (NHS, reviewed 2026).
Start with the whole picture, not the embryo
Pregnancy loss has many possible contributors, and the NHS notes that a cause is not always found. Its list of risk factors includes (NHS, reviewed 2026):
- Being 35 or over, or a father aged 45 or over
- Smoking, heavy caffeine or alcohol use
- Obesity or being underweight
- Conditions such as diabetes, a blood-clotting condition or a thyroid condition
- A problem with the womb, or low progesterone
- Vitamin D deficiency
Embryo testing addresses only one category: chromosome problems in the embryo. If a clotting condition, a uterine problem or poorly controlled diabetes is part of your picture, testing embryos will not touch it. That is why the order matters. Investigate first; decide about PGT after.
Three kinds of PGT, three different jobs
| Test | What it looks for | When it fits recurrent loss |
|---|---|---|
| PGT-A | Embryos with too many or too few chromosomes | Sometimes considered when embryo chromosome errors are thought to be driving losses, often linked to egg age |
| PGT-SR | Unbalanced chromosome rearrangements | When a parent is known to carry a balanced rearrangement, such as a translocation, that can lead to unbalanced embryos |
| PGT-M | A specific inherited single-gene condition | Only when a known genetic condition is involved; not a general miscarriage test |
PGT-SR is the most targeted of these for loss, because it is aimed at a known, specific cause found in a parent's own chromosomes. PGT-A is broader and is where most of the debate sits.
What the UK regulator says about PGT-A
The UK's fertility regulator gives PGT-A more than one rating, because it does different things for different outcomes (HFEA, 2023):
- Reducing miscarriage, most patients: green. High-quality evidence shows it is effective at lowering the chance of miscarriage for most fertility patients.
- Chance of having a baby, most patients: red. Because it is a selection tool, it often reduces the number of embryos available for transfer, and time to a birth may be longer.
- Older patients: grey for both outcomes, because there is not enough good-quality evidence.
The regulator notes that some studies suggesting fewer miscarriages in older women, or in women with a history of miscarriage, looked at this as a secondary outcome the studies were not designed to test, so those results may be less reliable. It also stresses that fewer miscarriages does not necessarily mean a higher chance of a baby.
Why both things can be true
Here is an illustrative example, not real data. Imagine five embryos. Without testing, they would be transferred one at a time; some might not implant, one might miscarry, one might lead to a birth. With testing, the embryos predicted to be abnormal are set aside, so transfers that would have miscarried are avoided. But if the test wrongly labels a healthy embryo as abnormal, or a biopsy damages one, that chance is lost too. The miscarriage count can fall while the total chance of a baby from the group stays the same, or even drops.
The trade-offs to weigh
The same HFEA page lists the risks for embryos (HFEA, 2023):
- The test may miss an abnormality, or report one that is not there
- Taking cells may damage an embryo and stop it developing
- Some results come back "mosaic", a mix of normal and abnormal cells; clinics handle these differently
- If every embryo is reported abnormal, there may be nothing to transfer
- Testing does not remove the chance of miscarriage from other causes
The page says PGT-A carries no additional known risks for the person having treatment. The costs are emotional and financial: another layer of results, often a freeze-all cycle while waiting, and an extra charge. For mosaic results, our guide on mosaic embryos after PGT-A explains why clinic policy matters.
If you conceive naturally but keep losing pregnancies
This situation deserves its own mention. Some people with recurrent loss have no trouble getting pregnant. For them, IVF with PGT means taking on stimulation, egg collection and lab costs in order to choose embryos, rather than to overcome infertility. That can still be a reasonable choice, for example with a known parental rearrangement, but it is a very different decision from IVF for infertility. Ask your doctor to spell out what IVF would be adding in your specific case.
Timing and travel
Testing usually means embryos are frozen while results come back, so transfer happens in a later cycle. If you are being treated away from home, plan for two trips, and ask how results will be shared with you and in what format, so you can review them with your own doctor.
Questions to ask before agreeing to PGT
- What did my recurrent-miscarriage tests show, and what is still unknown?
- Is the testing you suggest PGT-A, PGT-SR or PGT-M, and why that one?
- Was tissue from a previous loss tested, and what did it show?
- How many embryos would you expect to have available after testing at my age?
- How does your lab report and handle mosaic results?
- If I do not use PGT, what would my plan look like instead?
Support matters as much as testing
Repeated loss is grief, often unacknowledged and repeated. Adding IVF and genetic testing brings new rounds of waiting. Counselling, which the NHS recommends for anyone having IVF (NHS, reviewed 2025), can help with both the losses and the decisions ahead.
PGT content on this site is scoped strictly to chromosomal screening (PGT-A) and known genetic disease screening (PGT-M/PGT-SR) — not sex selection or non-medical trait selection.
The Takeaway
PGT can reduce miscarriages caused by embryo chromosome problems, and PGT-SR is targeted when a parent carries a rearrangement. It does not address other causes of loss and has not been shown to increase the chance of a baby for most patients. Get a full assessment first, then decide.
Frequently asked questions
Will PGT tell me why my previous pregnancies ended?
No. PGT tests new embryos, not past pregnancies. Testing tissue from a loss, where available, is a separate test that may give clues about that pregnancy.
Is IVF with PGT the standard treatment for recurrent miscarriage?
Not for everyone. It is one option for some people, particularly when a chromosome cause is known or suspected. A specialist assessment should guide whether it fits.
If a tested embryo miscarries, did the test fail?
Not necessarily. Testing looks only at chromosome number or specific rearrangements. A pregnancy can end for other reasons, and the test can occasionally be wrong.
Should my partner be tested too?
Often yes. Chromosome tests on both partners can show whether one carries a balanced rearrangement, which is the situation where PGT-SR is most clearly aimed.
Is it normal to feel afraid of trying again?
Yes. After repeated loss, many people find that a new pregnancy brings fear as well as hope. Telling your care team helps; some clinics offer extra early scans or counselling for exactly this reason.