Short answer: adenomyosis is a condition of the muscle wall of the womb, it is common in women having fertility treatment, it is frequently missed on scans, and it does appear to lower the chance of a live birth from IVF while raising the risk of miscarriage.
What we cannot tell you — and what almost every page about this will imply — is that there is a proven treatment for it. There is not one. That is an uncomfortable thing for a fertility clinic to write, so let us explain why we are writing it anyway.
The lining of the womb, the endometrium, normally sits on the inside. In adenomyosis, endometrial tissue — glands and the supporting stroma — is present within the muscle wall of the womb, the myometrium. That tissue responds to the same hormones, so the muscle becomes thickened, inflamed and often enlarged.
It commonly causes heavy periods and significant period pain. It can also cause nothing at all.
One clarification, because it is a persistent source of confusion: adenomyosis is not a type of endometriosis. The two often occur together, but the international working group that defined adenomyosis in 2021 was explicit — it “is not considered a form or subtype of endometriosis”. ESHRE’s 2022 endometriosis guideline excludes it for exactly that reason and promised separate adenomyosis guidance, which has not yet appeared.
We are giving you a range rather than a number, because a single number would be false precision.
Why such a spread? Because until recently adenomyosis was diagnosed by examining a womb after hysterectomy — so almost exclusively in older women who had finished having children. Ultrasound and MRI changed who gets diagnosed, and the diagnostic criteria are still settling. As one major review put it, “the diagnostic criteria are still not universally agreed”, and histology itself “has poor inter-observer reproducibility, leading to extreme variations in the prevalence of disease”.
So the honest version: common in fertility populations, probably a quarter to a third, and truly unknown in the general population.
A good transvaginal ultrasound, performed by someone looking for it.
That last clause is the whole problem. NICE guideline NG88 recommends offering “transvaginal ultrasound (in preference to transabdominal ultrasound or MRI)” where a woman has heavy periods with significant period pain, or a bulky, tender uterus on examination that suggests adenomyosis. Transabdominal ultrasound — the scan over the belly — and MRI are second choices, with their limitations explained.
MRI is often assumed to be the gold standard. On the evidence it is not better. A meta-analysis of six head-to-head studies in 595 women found transvaginal ultrasound had sensitivity 75% and specificity 81%, against MRI’s 69% and 80% — with no statistically significant difference. Heterogeneity was high in both.
The sonographic features were standardised in 2022 by expert consensus, the MUSA criteria, which separate direct signs — myometrial cysts, hyperechogenic islands, and echogenic subendometrial lines and buds — from indirect ones such as a globular uterus, asymmetrical muscle thickening, fan-shaped shadowing and an irregular or interrupted junctional zone.
Two honest caveats. That consensus is expert agreement, not a formal guideline. And the criteria have barely been validated against actual tissue — the only blinded study we could find involved 26 wombs, and while the direct markers picked up every case, specificity was only 35.7%.
Practically: if you have heavy, painful periods and you are having fertility treatment, it is worth asking whether anyone has specifically looked for adenomyosis. It is not something that jumps out of a routine follicle-tracking scan.
Here the evidence is reasonably consistent in direction. All of it is observational — there is no randomised trial comparing outcomes with and without adenomyosis, because you cannot randomise a diagnosis.
A 2022 meta-analysis found that, compared with women without adenomyosis, women with it had:
A separate 2021 review of 17 observational studies found much the same after assisted reproduction: clinical pregnancy odds ratio 0.69 (0.51–0.94), miscarriage odds ratio 2.17 (1.25–3.79). A 2019 review found a miscarriage odds ratio of 3.40 (1.41–8.65) across any route to conception.
Now the caveat that the authors themselves insist on, and which we think you are entitled to. From the 2022 meta-analysis: “the major part of the studies has not divided focal and diffuse adenomyosis, and this represents a relevant source of bias: studies conducted with standardized diagnostic criteria for adenomyosis are still needed”. A 2023 review adds that these studies show “substantial qualitative and quantitative heterogeneity”, making reliable assessment “difficult, and caution should be exercised”.
So: directionally real, and we treat it as real. But not a number to convert into “your chance is X%”. Adenomyosis ranges from a small focal patch to a womb thoroughly involved, and the studies mostly did not separate the two.
The standard offer: a few months of injections to suppress your cycle and shrink the adenomyosis before an embryo transfer. It is widely used and it sounds logical.
Four meta-analyses have examined it. They disagree with each other.
There is no randomised trial. All four reviews draw on overlapping small retrospective studies. The most favourable finding is a clinical pregnancy signal in fresh transfers with no demonstrated live birth benefit; the least favourable suggests it may be actively worse than a standard antagonist protocol.
What that means for you: if a clinic offers you three months of down-regulation for adenomyosis and presents it as established, that is more confident than the evidence allows. It may be reasonable in your case. It is not proven, it delays treatment by months, and you should be told both.
Adenomyomectomy — surgically removing adenomyotic tissue — has been reviewed across 32 studies and 2,501 women, and the review states plainly that no randomised trials exist. Pooled figures afterwards: 50.1% became pregnant, 39.5% delivered, 19.8% had a pregnancy loss.
Those are single-arm numbers with no comparison group, so they cannot tell you whether surgery helped. One figure from the same review deserves attention before anyone signs a consent form: the caesarean section rate afterwards was 99.6%. Operating on the muscle wall of the womb has consequences for how a subsequent pregnancy can be delivered.
Almost nothing, and that is itself informative. NICE NG257, the current UK fertility guideline published in March 2026, does not mention adenomyosis at all. ESHRE’s endometriosis guideline explicitly excludes it. NICE’s heavy menstrual bleeding guideline acknowledges the gap directly, saying a better understanding of the impact of adenomyosis on pain, bleeding and “subfertility” is needed.
The one guideline sentence we found placing it in a fertility context comes from ESHRE’s recurrent pregnancy loss guideline: “all women with RPL could have 2D ultrasound to rule out adenomyosis”. Worth knowing if you have had repeated miscarriages and nobody has scanned for it.
It commonly coexists with endometriosis and with fibroids. In the UK study above, adenomyosis was significantly associated with pelvic endometriosis. In the assisted-reproduction study, 35.1% of women with adenomyosis also had endometriosis. A 2024 analysis of 505 patients found that fibroids were independently associated with adenomyosis inside the womb wall, while deep endometriosis and never having been pregnant were associated with the outer type.
This matters for one decision in particular. In women having surgery for deep endometriosis, a pooled analysis found that 11.9% of those who also had adenomyosis conceived afterwards, against 43.0% of those without it — a relative risk of 0.32 (0.16–0.66). The authors’ conclusion: screening for adenomyosis before recommending “difficult and risky procedures” may identify women for whom surgery “would have a marginal effect on the likelihood of conception”.
In other words, if you are being offered major surgery for endometriosis in order to conceive, knowing whether you also have adenomyosis genuinely changes the calculation.
There is a broader point here too, put well in a 2023 review: “emerging evidence suggests that some adverse reproductive and obstetric outcomes observed in women with endometriosis are, in fact, associated with coexisting adenomyosis”, with the effect “larger in women with adenomyosis”.
We look for it. Dr Ranganathan’s background is in advanced gynaecological and fertility ultrasound, including Doppler studies, and adenomyosis is one of the things a careful scan by someone expecting to find it will pick up and a quick scan will not.
If we find it, what changes is the conversation rather than a product we sell you:
A female fertility assessment, including an ultrasound and a consultation with the results explained by a person, is £390. A saline scan of the womb cavity is £300. All prices are on our prices page.
Yes. Plenty of women do, including without treatment. The evidence points to lower odds and a higher miscarriage risk, not to impossibility, and the effect almost certainly depends on how extensive it is.
No. Endometriosis is endometrial-type tissue outside the womb; adenomyosis is inside the muscle wall of the womb itself. They frequently occur together, which is why one often hides the other.
Because for most of medical history it could only be diagnosed after hysterectomy, and because it takes a deliberate look on a transvaginal scan. It is one of the most under-diagnosed conditions in gynaecology, and heavy painful periods are still too often treated as normal.
Possibly, and reasonable clinicians differ. What you should not be told is that it is proven — four meta-analyses disagree, none of the underlying studies is randomised, and the most recent suggests it may be worse than a standard protocol. Ask for it to be framed as a judgement call, because that is what it is.
Unknown. There are no randomised trials, the published pregnancy rates have no comparison group, and nearly every subsequent birth in those studies was by caesarean. It may be right for severe symptoms. As a fertility treatment it is unproven.
It is oestrogen-dependent and tends to progress through the reproductive years before settling after the menopause. That is an argument for not spending years being told your periods are normal, and it is a reason age matters more here rather than less.
The miscarriage association is the most consistent finding, and there is emerging evidence linking adenomyosis to obstetric complications previously attributed to endometriosis. It is worth being in your notes and worth your obstetric team knowing about.
If you have heavy, painful periods and fertility treatment that has not worked, ask whether anyone has actually looked for this. Start with a free 15-minute consultation with a Fertility Specialist — no referral needed, no obligation. Book a free consultation, or read about our fertility assessments.
