Danish researchers combined 29 studies and found that diffuse adenomyosis was associated with less favorable live birth outcomes.
Lesions near the uterine lining were also associated with outcomes, suggesting that location and extent deserve attention before IVF.
A diagnosis of adenomyosis does not mean every woman has the same reproductive outlook. A new review suggests that pregnancy and live birth outcomes can differ according to where lesions occur and how widely they extend.
Diffuse adenomyosis spread through the uterine muscle, and adenomyosis close to the uterine lining, were associated with lower odds of live birth.
A team including researchers at Odense University Hospital in Denmark published a review of 29 studies involving 19,510 women in EBioMedicine on October 21, 2026. They examined reproductive outcomes in relation to both the presence of adenomyosis and its pattern and location.
The analysis included 7,569 women with adenomyosis
Adenomyosis occurs when tissue resembling the uterine lining is present within the muscular wall of the uterus. It can cause severe menstrual pain, heavy periods and pelvic pain, and is associated with infertility or miscarriage in some women.
Nevertheless, it does not inevitably prevent pregnancy. Some women have no symptoms, some conceive naturally, and others have a baby following IVF.
To explore whether lesion pattern and location help explain these differences, the researchers systematically reviewed 29 studies. Of the 19,510 women included, 7,569 had adenomyosis.
They classified ultrasound features and analyzed their associations with clinical pregnancy, miscarriage and live birth.
Diffuse adenomyosis: a live birth odds ratio of 0.52
One of the main findings concerned differences in live birth outcomes between adenomyosis patterns.
Women with diffuse adenomyosis extending across a broad area of uterine muscle had lower odds of live birth than women without adenomyosis. The odds ratio was 0.52.
A similar association was found for adenomyosis in the inner myometrium, the muscle layer closer to the uterine lining. The live birth odds ratio was 0.49.
An odds ratio below 1 indicates lower odds of the outcome relative to the comparison group. An odds ratio of 0.52 should not be interpreted as an exact 48% reduction in the live birth rate. An individual's probability also depends on age, infertility factors, ovarian function, embryo characteristics and treatment.
The findings suggest that reproductive outcomes can differ among women sharing the same adenomyosis diagnosis.
Why might lesions near the uterine lining matter?
Location was another focus of the review. Adenomyosis close to the endometrium was associated with less favorable live birth outcomes.
The endometrium is where implantation and placental development begin. Adenomyosis may alter uterine muscle structure, contractions, inflammation and the environment for implantation.
The interface between the lining and muscle is closely related to normal uterine function. Disease in this area could plausibly affect contractions or the implantation environment.
However, this review examined associations between lesion location and outcomes. It did not establish that adenomyosis in a particular location directly causes implantation failure.
Assessing extent and location before IVF
The findings are relevant to women preparing for IVF.
Assessment has often focused on whether adenomyosis is present. This analysis suggests a need to consider whether disease is diffuse or localized and how close it lies to the uterine lining.
After repeated implantation failure or miscarriage, a broader assessment may be helpful: lesion pattern and extent, uterine size, and coexisting fibroids or endometriosis all deserve consideration.
Finding adenomyosis does not automatically mean IVF should be delayed or surgery performed first. Evidence for improvements in live birth following adenomyosis treatment varies by patient circumstances and treatment. This review did not test a specific therapy.
Individual assessment, with substantial uncertainty
The researchers emphasized that reproductive outcomes may differ with ultrasound features. A diagnostic label alone offers less information than a detailed assessment of lesion pattern and location.
The evidence needs careful interpretation. Certainty was rated low or very low for most outcomes because diagnostic definitions, patient characteristics and fertility treatments differed across studies.
These findings cannot precisely predict an individual woman's chance of pregnancy or justify one treatment strategy for everyone with adenomyosis.
They nevertheless support looking beyond adenomyosis as a single uniform condition and considering differences in lesion location and pattern.
The diagnosis alone is not a reason to assume pregnancy is unlikely. What matters is assessing where lesions are, how extensive they are and how those features relate to the individual's fertility circumstances.
Source: A systematic review and meta-analysis of ultrasound features of adenomyosis and reproductive outcomes by researchers including Odense University Hospital, Denmark. EBioMedicine, online October 21, 2026, article 106518. DOI: 10.1016/j.ebiom.2026.106518.
Lesion pattern and location do not determine an individual's reproductive outcome. Decisions about fertility treatment, surgery or medication should be made with a gynecologist or fertility specialist.
Related reading: Related research on endometriosis, a distinct condition: pain and tissue changes in a mouse study.
Copyright © 2026 Fertility Information TokTok Fertility News | THE FERTILITY NOTES. All rights reserved. Unauthorized republication, reproduction, redistribution, scraping, AI training and data use of any content, including articles, photographs and images, are strictly prohibited. Violations may result in legal liability.