Endometriosis is a chronic, benign, estrogen-dependent disease characterized by endometrial tissue that is implanted outside the uterus into the ovaries, intestines, or peritoneum but also outside the pelvis. It is a common disease that affects 7-10% of women around the world. The most common symptoms are pain and infertility. The diagnosis is histological after removal of lesions with laparoscopy (sensitivity 94%, specificity 79%), and treatment is symptomatic.

At present, there is not a laboratory test that allows early and adequate diagnosis of endometriosis and therefore it can take up to 10 years for a patient to be diagnosed and patients often suffer from the disease.

The purpose of our study is to investigate biomarkers associated with endometriosis and prove their use in the diagnosis and staging of endometriosis. The biomarkers will be studied even in relationship to clinical manifestations of the disease, as markers of relapse and as fertility markers. Meanwhile, quality of life of patients with advanced stages of endometriosis postoperatively will be studied.

IInclusion Criteria:

• women of reproductive age (18-45) who are operated because of suspected endometriosis (dysmenorrhea, dyspareunia, infertility, etc.) (patient group)
• women of reproductive age (18-45) who are operated for other benign gynecological causes with laparoscopy (ovarian cysts, sterilization, fibroids, etc.) and are found without macroscopic endometriosis perioperatively and confirmed with blind biopsies (control group
• talk swedish or english in order to complete questionnaires and give informed consent for their participation in the study.

Exclusion Criteria:

• BMI> 40
• postmenopausal women
• premature ovarian failure
• pelvic inflammatory disease (PID)
• current or previous malignancy
• pregnancy and 6 months postpartum
• corticosteroids in the last 3 months
• pituitary, kidney, liver, adrenal disease
• endometrial hyperplasia or endometrial polyp
• cardiovascular or systemic inflammatory diseases.

Participants will be recruited in several gynecological clinics around Sweden. A total of 345 women of reproductive age will be included in the study according to the power calculation. 115 patients who are operated on due to deep infiltrating endometriosis or rASRM III-IV in national endometriosis centers in Sweden, 115 patients who are diagnosed during surgery with early-stage endometriosis (rASRM I-II) and 115 patients who are controls, who are operated on for others benign gynecological diseases (fibroids, ovarian cysts, chronic abdominal pain, sterilization) and have no signs of endometriosis perioperatively.