Epidemiology of subtle, typical, cystic, and deep endometriosis: a systematic review

Endometriosis is known as a cause of pelvic pain and infertility. The epidemiology of endometriosis is important since the prevalence and severity of endometriosis might be linked to pollution and to our modern lifestyle, comprising food intake, chemical disruptors, postponement of the first pregnancy, and stress, as indicated by “a career women’s disease.” Epidemiological data based upon hospital discharge records should be viewed with caution. Indeed, that subtle lesions are considered pathology causes a major increase in prevalence, while the laparoscopic recognition and histological confirmation of subtle and typical lesions vary with the expertise and interest of the surgeon. The epidemiological data published by surgical groups on severe forms, as cystic and deep endometriosis, have a referral bias and lack the numbers required for meaningful statistics. Fundamental to understanding epidemiology of endometriosis is that it is unclear that all presentations of endometriosis constitute one disease. We therefore performed a systematic review of the incidences and severity of subtle, typical, cystic, and deep endometriosis lesions separately. The only data found were that severe endometriosis carries a greater hereditary risk and that the prevalence of subtle endometriosis decreases with age whereas the prevalences of typical, cystic, and deep endometriosis increase with age. Surgeons that witnessed over the last 20 years in over 1000 interventions each the evolution of deep endometriosis, however, had a strong impression that severity and prevalence of deep endometriosis are increasing. In conclusion, there are no solid epidemiologic data of each type of endometriosis separately. With all restrictions imposed by the referral bias and by a clinical impression, the consistency of the observation of deep endometriosis surgeons should be a reason for concern. The investigation of the epidemiology of deep endometriosis is suggested since it is relevant because it is clinically severe pathologic and feasible since it can be done from hospital-based records. Indeed, most women will ultimately have surgery with solid information on severity and an unbiased diagnosis if defined as “adenomyosis externa.”