What is the prevalence and incidence of endometriosis?

Prevalence and Incidence of Endometriosis

Endometriosis affects approximately 2% to 10% of women of childbearing age worldwide, translating to approximately 176 million women globally, with a diagnosed prevalence of up to 10% in reproductive-age women in the United States. 1, 2, 3

Epidemiological Data

• Endometriosis is characterized by the presence of nonmalignant endometrium-like tissue (glands and/or stroma) outside the uterus 1
• The prevalence is estimated at 5-10% of women in their reproductive years globally 3, 4
• In the United States, endometriosis affects approximately 9 million women 2
• The prevalence is significantly higher (25-40%) among women with infertility compared to 0.5-5% in fertile women 5
• Definitive diagnosis requires surgical visualization with histological verification, making accurate prevalence estimation challenging 3

Risk Factors and Demographics

• Risk factors include younger age at menarche, shorter menstrual cycle length, lower body mass index, nulliparity, and congenital obstructive müllerian anomalies 2
• The condition is typically diagnosed during reproductive years, identifying an at-risk group in early adulthood 1
• Diagnosis is often delayed by 5-12 years after symptom onset, with most women consulting 3 or more clinicians prior to diagnosis 2
• The true prevalence may be underestimated due to diagnostic challenges, as definitive diagnosis requires laparoscopy 1

Associated Conditions and Comorbidities

• 90% of people with endometriosis report pelvic pain, including dysmenorrhea, nonmenstrual pelvic pain, and dyspareunia 2
• 26% of women with endometriosis report infertility 2
• Endometriosis is associated with hypercholesterolemia, hypertension, hypertensive disorders of pregnancy, and increased cardiovascular disease risk 1
• Recent high-quality observational studies have consistently found a 16% to 34% increased risk of stroke among those with endometriosis 1
• Endometriosis is now considered a systemic disease rather than a disease predominantly affecting the pelvis, affecting metabolism in liver and adipose tissue, leading to systemic inflammation, and altering gene expression in the brain 4

Clinical Implications

• Endometriosis substantially affects the quality of life of women and their families and imposes costs on society similar to those of other chronic conditions such as type 2 diabetes mellitus, Crohn's disease, and rheumatoid arthritis 3
• Screening for a history of endometriosis is reasonable to inform the risk of stroke 1
• In individuals with endometriosis, vascular risk factor evaluation and modification are reasonable to reduce the risk of stroke 1
• The economic burden of endometriosis is substantial due to direct healthcare costs, lost productivity, and impact on quality of life 3, 6

Diagnostic Challenges

• Diagnosis is reliably established only through surgical visualization with histological verification, although ovarian endometrioma and deep nodular forms can be detected through ultrasonography and MRI 3
• The World Endometriosis Society recommends a classification toolbox that includes the revised American Society for Reproductive Medicine staging system and, where appropriate, the Enzian and Endometriosis Fertility Index staging systems 1
• Normal physical examination and imaging do not exclude the diagnosis of endometriosis 2

Understanding the high prevalence and systemic nature of endometriosis is crucial for early recognition, proper diagnosis, and comprehensive management to improve outcomes and quality of life for affected women.