Endometriosis is a chronic inflammatory disease affecting ~10% of women of childbearing age. It is characterized by the presence of endometrial-like tissue outside the uterus, causing lesions and adhesions between the organs, and is often accompanied by intense pain and sometimes infertility. The four-stage classification based on the severity of lesions does not always reflect the severity of symptoms. Adenomyosis, a similar pathology, is often present in the same patients, although it is now considered distinct from endometriosis. Diagnosis usually takes a long time, with an average delay of 7 years. The cause of the disease remains unknown, but hormonal, genetic and environmental factors, such as exposure to endocrine disruptors, are suspected. Persistent organic pollutants (POPs), such as dioxins and PCBs, may influence the risk and severity of the disease. Although experimental studies suggest a link between these substances and the progression of endometriosis, epidemiological research on the subject is still limited.

The central hypothesis of the POPENDO project is that higher concentrations of persistent organic pollutants (POPs) are associated with increased severity of endometriosis. The aim of the study is to explore the associations between serum levels of four families of POPs (PCBs, organochlorine pesticides, PFAS and BFR) and endometriosis.

Inclusion Criteria:

• ComPaRe participants ⩾ 18 years old. All ComPaRe participants are at least 18 years of age, so our research participants will all be adults.
• Having declared in ComPaRe that they had endometriosis
• Living in the Ile-de-France region (departments 75, 77, 78, 91, 92, 93, 94 or 95);
• Have given electronic consent stating: "By checking this box, I agree to be solicited for research outside ComPaRe"; This criterion is collected at the time of ComPaRe registration, when consent is collected. Participants can withdraw this consent at any time on their secure personal online account on the ComPaRe platform.
• Aged ≤ 45 years to avoid including premenopausal or menopausal women;
• In possession of MRI images used to diagnose their endometriosis (CD-ROM) that are no more than 5 years old;
• Enrolled in or benefiting from a social security scheme.

Exclusion Criteria:

• - People with contraindications to blood sampling will not be included in this research:

• Known severe anemia

• Hemophilia/coagulation disorders/anticoagulant use

• People with HIV, HBV or HCV will not be included in this study due to the risk of BSE (Blood Exposure Accident).

• Based on factors that may disrupt lipid dynamics and lipid pollutants, the following individuals will not be included:

• Pregnant and breast-feeding women

• People suffering from any of the following diseases:

  • Cancer
  • Morbid obesity (BMI>40)
  • Non-alcoholic steatohepatitis (NASH)

• Persons under court protection/guardianship/guardianship will not be able to participate in this research.

The study population will be a group of female volunteers who have self-reported endometriosis. The group size will be a random sample of 650 women from the ~10,000 participants included in the ComPaRe-Endometriosis sub-cohort.