This content is WordProof timestamped
Main article: Endometriosis Overview
Updated: 2-April-2024
Causes of Endometriosis
To begin understanding endometriosis and find some common links, numerous epidemiology studies were carried out. We know women with short menstrual cycles, above average height and early menarche are at higher risk of endometriosis, whilst giving birth, smoking and higher BMI is associated with a lower risk of endometriosis. Genetically women with a family history of endometriosis are also at greater risk, with the condition found to be 9 times more likely in Asian women compared to European or American women.
| Factors associated with increased risk |
| – Low birth weight / Small for gestational age – Earlier age of menarche – Shorter menstrual cycle length – Taller height – Vitamin D deficiency – Alcohol intake – Caffeine intake |
| Factors associated with decreased risk |
| – Nulliparity – Current oral contraceptive use – Smoking – Higher body mass index – Regular exercise – Fish and omega 3 fatty acids– – |
Risk factors for Endometriosis
Experts suggest these factors are more likely a consequence and not the cause of endometriosis.
Although the exact cause of endometriosis is still unknown, there are 6 main theories:
- Retrograde menstruation
- Coelomic Metaplasia
- Embryonic Rests
- Lymphovascular metastasis
- Stem Cell Origin
- Low testosterone
Some experts also suggest the condition could be multifactorial.
Retrograde Menstruation
To date, this is the oldest and most widely accepted theory among experts who believe that fragments of endometrial tissue can renew itself in women with specific cellular and molecular abnormalities. During menstruation these shed fragments flow back via the fallopian tubes into the peritoneal cavity, where they become implanted, leading to endometriosis.
Source: Bulun S E, et al. (2022)
If this is true, sex during menstruation may inadvertently accelerate the development of endometriosis.
Source: Mollazadeh S, et al. (2023)
Although studies show the majority of healthy women experience retrograde menstruation which suggests there must be other contributing factors, such as molecular defects, immunologic abnormalities or infection (e.g. Fusobacterium). Medical professionals have also found endometriosis lesions in other parts of the body where retrograde menstruation does not occur such as the lungs. Meanwhile endometriosis has also been identified in some premenarchial adolescents and fetuses leading to other theories.
