Recurrent Pregnancy Loss Research: Understanding the Role of Chromosomal Abnormalities

If you've experienced recurrent pregnancy loss, one of the hardest parts can be not knowing why.

You may have had investigations, blood tests and appointments, only to be told that everything looks “normal”, leaving you wondering what happened and whether there is something you could have done differently.

The reality is that recurrent pregnancy loss (RPL) is complex, and we don't always have a clear explanation.

Research presented at ESHRE highlights an important part of this picture: around 50% of recurrent pregnancy losses are associated with chromosomal abnormalities, while the remaining losses may be unexplained.

So, what does this actually mean?

What is aneuploidy?

Aneuploidy means that an embryo has an abnormal number of chromosomes.

For an embryo to develop normally, it generally needs the correct number of chromosomes.

When there is an extra or missing chromosome, this can prevent normal development and is a common cause of early pregnancy loss.

Chromosomal abnormalities can happen randomly as an embryo develops and become more common with increasing age.

Importantly, experiencing a chromosomally abnormal pregnancy does not mean that you or your partner have necessarily done anything wrong.

What does the research tell us?

A study by Mumusoglu et al., published in Fertility and Sterility in 2024, explored preimplantation genetic testing for aneuploidy (PGT-A) in people experiencing unexplained recurrent pregnancy loss.

The research adds to our understanding of the potential role of embryo chromosome status in recurrent loss.

However, one of the most important things to take away is that chromosomal abnormalities don't explain every recurrent pregnancy loss.

If around half of losses are associated with aneuploidy, that leaves another group where the reason for the losses isn't explained by embryo chromosome abnormalities alone.

And this is where things become more complicated.

What about the other 50%?

There isn't one single explanation for the remaining cases.

Depending on your individual history, we may consider a range of factors that can influence pregnancy outcomes (some of which we refer you to expert gynaecologists to explore), including:

1. Uterine and reproductive factors

The structure and health of the uterus can play an important role in pregnancy.

This may include looking at things such as uterine abnormalities, fibroids, polyps or other conditions that could affect implantation or pregnancy development.

2. Hormonal and metabolic health

Hormones provide the environment needed to support ovulation, implantation and early pregnancy.

Depending on your circumstances, this may include assessing thyroid function, progesterone and other hormonal or metabolic factors.

3. Immune and autoimmune factors

Certain autoimmune conditions are associated with an increased risk of pregnancy loss - including thyroid disorders (such as Graves or Hashimoto’s), Lupus, Anti-Phospholipid Syndrome, Celiacs, IBD and Type 1 Diabetes.

Where appropriate, these should be explored based on your personal and family history.

4. Genetic factors

Chromosomal abnormalities are not the only genetic consideration.

In some circumstances, a fertility specialist may recommend genetic testing (known as karyotyping) for you or your partner, particularly where there is a relevant family history or specific pattern of pregnancy loss.

5. Lifestyle and nutritional health

Nutrition isn't a guarantee against miscarriage, and it's important not to place blame on yourself.

However, optimising nutritional status, metabolic health, sleep, movement and other lifestyle factors can form part of a wider approach to supporting reproductive health.

Does this research mean everyone needs PGT-A?

No.

PGT-A can provide information about the chromosome status of embryos, but it isn't appropriate or necessary for everyone undergoing IVF, and its potential benefits can vary depending on individual circumstances.

The decision to use PGT-A should be made with your fertility specialist or IVF clinic, taking into account factors such as age, embryo numbers, previous treatment history and your individual reproductive history.

It's also important to remember that PGT-A is a screening test rather than a guarantee of a healthy pregnancy - it does not improve clinical pregnancy rates but it can reduce the time to pregnancy.

What I want women experiencing recurrent loss to know

If you've experienced recurrent pregnancy loss, please know that it isn't your fault.

There can be an understandable desire to search for the one thing you ate, didn't eat, did or didn't do that caused a pregnancy to end.

But pregnancy loss is incredibly complex, and in many cases there simply isn't one lifestyle factor that explains why it happened.

As mentioned, around half of recurrent pregnancy losses may be associated with chromosomal abnormalities, while many others remain unexplained despite investigation.

That uncertainty can be incredibly difficult, but it also means you shouldn't feel that you need to carry the blame.

Looking at the whole picture

The more we learn about recurrent pregnancy loss, the clearer it becomes that there isn't a one-size-fits-all explanation or treatment.

For some people, chromosome abnormalities may be an important part of the picture. For others, there may be another contributing factor, and for some, there may still be no clear explanation despite thorough investigation.

This is why I believe in a personalised approach.

Your medical and reproductive history should guide which investigations are appropriate, rather than simply ordering every available test.

And if nutrition support is appropriate for you, this can sit alongside medical care to help optimise nutrient status, metabolic health and overall wellbeing before trying again or undergoing fertility treatment.

Most importantly, if you've experienced recurrent pregnancy loss, you deserve compassionate care, appropriate investigation and support, without being made to feel that your body has somehow failed you. 

References

Mumusoglu, S. et al. (2024). Preimplantation genetic testing for aneuploidy in unexplained recurrent pregnancy loss: a systematic review and meta-analysis. Fertility and Sterility.

ESHRE 2026 - research presented on recurrent pregnancy loss and aneuploidy.