Study of Real Clinical Practice to Evaluate the Effects of Oral Dydrogesterone for Treatment of Confirmed Endometriosis

Inclusion Criteria: * Female, aged ≥ 18 years and ≤ 45 years. * Complaints on chronic pelvic pain with or without dysmenorrhea assessed by 11-items NRS. * External genital endometriosis confirmed by laparoscopy. * Existing pelvic (vaginal) ultrasound data not earlier than 2 months before inclusion in the study. * Prescribed treatment with Duphaston® according local labelling for treatment of endometriosis 10 mg 2-3 times a day from the 5th to the 25th day of the menstrual period cycle or continuously. * No hormonal treatment in 2 cycles before enrollment. * Signed Patient Authorization for Use/Disclosure of Data. Exclusion Criteria: * Any co-existing disease(s) needing chronic drug therapy (e.g. Crohn's disease, diabetes etc); Severe concomitant medical illness. * Severe other genital pathology excluding endometriosis (e.g. Multiple/severe myoma; adenomyosis, inflammatory diseases, etc.). * Routine consumption of analgesics other than for the pain of endometriosis. * Patients receiving hormonal contraceptives in last 2 cycles (including intrauterine devices, contraceptive patches, contraceptive rings, oral contraceptives etc.). * Ongoing pregnancy. * Menopause or premature ovarian failure. * Contraindications to dydrogesterone treatment listed in the locally approved label (Instructions for the medical use of Duphaston®). * Any other condition that precludes use of dydrogesterone in a particular patient, in accordance with the precautions and special warnings listed in the locally approved label (Instructions for the medical use of Duphaston®). * Abnormal results of pap smear test. * Other conditions that made the patients participation impossible (based on the investigator decision). * Fertility treatments using assisted reproductive technology.