Introduction:

Endometriosis is a common pathology affecting one in 10 women, characterized by the ectopic development of endometrium, which can cause pain and/or infertility. This pathology is primarily determined by hereditary factors, but it is also susceptible to environmental influences, such as the age of the onset of menstruation or exposure to chemical substances that modify the endocrine system. Recent studies have highlighted that endometriosis is more common in women with relatively short ano-genital distances (AGD), and that sensitivity to pain is closely linked to adult levels of testosterone (T) or oxytocin (OT).

Aim:

The main objective is to compare the anogenital distance (AGD) between two groups of women: one with stage III or IV endometriosis (ENDO +) and another group without endometriosis confirmed by laparoscopy (ENDO -).

The secondary objectives are to compare various factors between the 2 groups :

• Basal testosterone levels in blood.
• Variations in blood testosterone levels before and after a video stimulating empathy.
• Basal oxytocin levels in saliva.
• Variations in oxytocin levels in saliva before and after an empathy-stimulating video.
• Pelvic pain, between D2 and D5 after the start of the menstrual cycle.

For the ENDO + group only:

• Evaluate patients' quality of life, between D2 and D5 after the start of the menstrual cycle.
• Correlate pain experienced over the last 4 weeks with hormonal markers (AGD, T, OT).

Methods:

Participants in the ENDO+ group will fill in a questionnaire assessing the impact of pain experienced over the past 4 weeks on their quality of life. D0 is defined as the day when participants experience a menstrual bleed before 10 am. All participants will return for project-specific hospital appointment between D2 and D5 after the start of their menstrual cycle to measure T, Sex Hormone-Binding Globulin (SHBG) and OT.

During this consultation, the following samples will be taken:

• 10mL blood sample
• 2mL saliva sample

Both samples will be taken at t0 (before watching the video) and t1 (20 minutes after watching the video).

Inclusion Criteria:

• Nulliparous woman
• No hormonal contraception for at least 3 months
• Regular menstrual cycles (between 26 and 32 days) or proven ovulation (positive urine ovulation test ovulation test or progesterone level >3 ng/ml in the luteal phase)
• Normal BMI (≥ 18,5 and < 30 kg/m²)

Specific criteria (ENDO+ group) :

• Stage III or IV endometriosis confirmed by laparoscopy or by laparotomy or MRI
• Painful symptoms

Specific criteria (ENDO- group) :

• Patient without endometriosis confirmed by laparoscopy

Exclusion Criteria:

• Ovarian stimulation planned within 3 months
• Adenomyosis
• Use of a copper coil
• Polycystic ovary syndrome
• Pudendal neuralgia
• Episiotomy or lesion of the posterior perineum that may modify AGD
• Diabetes or thyroid disease
• Chronic liver failure, chronic renal failure, cardiac pathology, autoimmune disease
• Autism
• Diagnosis and/or treatment for psychiatric illness
• Chronic exposure to cocaine, methamphetamine, morphine or ecstasy within 30 days before the inclusion visit
• Chronic exposure to Tetrahydrocannabinol (THC) within 7 days prior to inclusion.
• Patient on treatment(s) that vary oxytocin (e.g. atosiban), testosterone or GnRH
• Pregnant or breast-feeding patient
• Patients who have given birth or breastfed within 6 weeks before the inclusion visit
• Patient unable to read French
• Failure to obtain informed consent
• Patient not affiliated with or not benefiting from a national health insurance scheme
• Person under legal protection, guardianship or curatorship
• Patient participating in other research involving the human person

Women with or without endometriosis