09/12/2026
Fibroids and endometriosis are usually discussed as separate conditions, but new research suggests their biology may overlap more than we previously understood.
In this 2026 study, researchers combined epidemiological, genetic, and molecular analyses to investigate whether the two conditions may share underlying mechanisms.
They analyzed data from 1,466 women in the National Health and Nutrition Examination Survey, where 2.7 percent had both endometriosis and uterine fibroids. Women with endometriosis had about 4.14 times the odds of also having fibroids compared with women without endometriosis.
The researchers then went further by analyzing genome-wide association study data and gene expression datasets. They identified two shared genetic regions involving WNT family member 4 and spectrin repeat containing nuclear envelope protein 1. WNT family member 4 was also more highly expressed in lesions from both conditions and was linked with pathways involving cell junction formation and collagen metabolism.
Why is this important?
If fibroids and endometriosis share some of the same underlying biology, studying those connections could help researchers better understand why some women develop both conditions and which biological mechanisms deserve closer investigation.
The study does not show that one condition causes the other, but it gives researchers new clues about how these conditions may be connected and where future fibroid research could go next.
There is still a great deal we do not understand about fibroids, and studies like this help move the science forward.
Source: Chen J, Tang L, Zou LL, Zhou CB, et al. “Comorbidity of Endometriosis and Uterine Fibroid: Genetic Insights from Cohort Analysis.” Reproductive and Developmental Medicine. 2026.
Full study:
Objective:Endometriosis (EM) and uterine leiomyoma (UL) are common gynecological disorders with substantial clinical overlap; however, their shared...