Gynecology & Reproductive Medicine & Family Medicine
Endometriosis
Endometriosis is a chronic, inflammatory, estrogen-dependent disease defined by the presence of functional endometrial tissue (endometrial glands and stroma) outside the uterine cavity. These ectopic implants - located mainly on the pelvic peritoneum, ovaries, uterosacral ligaments, recto-vaginal septum and more rarely on the diaphragm, intestine, bladder or lungs - respond to hormonal fluctuations of the menstrual cycle (estrogen-induced proliferation → desquamation and cyclic bleeding) but cannot evacuate the blood produced → chronic local inflammatory reaction → progressive fibrosis → pelvic adhesions → anatomical distortion. Endometriosis affects 10-15 % of women of childbearing age (around 1 in 10) and 35-50 % of women consulting for infertility or chronic pelvic pain, i.e. around 190 million women worldwide. Despite its high prevalence, the average delay between first symptoms and confirmed diagnosis remains 7-10 years - a delay linked to the trivialization of dysmenorrhea, the lack of clinical awareness and the absence of a specific biological marker. Pathophysiological mechanisms are multifactorial and imperfectly understood: Sampson's retrograde menstruation theory (reflux of viable endometrial cells through the fallopian tubes during menstruation into the peritoneal cavity) remains the most widely accepted, combined with immunological factors (failure of NK cells and macrophages to clear ectopic endometrial cells), genetic factors (heritability estimated at 50 %) and environmental factors (endocrine disruptors). There are three main anatomical forms: superficial peritoneal endometriosis (superficial implants on the pelvic peritoneum); ovarian endometriosis (endometriomas - ovarian cysts with chocolate hemorrhagic content - 17-44 % of cases) ; and deep infiltrating endometriosis (DIE - implants penetrating >5 mm below the peritoneal surface, affecting the uterosacral ligaments, recto-vaginal septum, rectum, bladder, ureters - most severe form - 20 % of cases).
Clinical Presentation and Symptomatic Picture
- Dysmenorrhea cardinal symptom — disabling menstrual pain occurring before and during periods (progressively worsening in intensity over cycles) — distinct from primary functional dysmenorrhea by its progressive worsening, its sometimes secondary onset (after years of painless periods), and its resistance to common painkillers (NSAIDs, acetaminophen); severe stage dysmenorrhea: VAS >7/10 — bedridden, school or work absenteeism — would be present in >70% % of adolescents whose dysmenorrhea is not relieved by NSAIDs → active search for endometriosis recommended
- Deep dyspareunia: pain during intercourse (with deep penetration) – suggestive of involvement of the uterosacral ligaments or rectovaginal septum – often aggravated in the premenstrual period; can lead to avoidance of intercourse and a major impact on quality of life and the couple's relationship; superficial dyspareunia: less specific, can be related to vaginal atrophy, associated vulvodynia
- Chronic pelvic pain (CPP): non-cyclical pelvic pain evolving for >6 months — present in 50–80 % women with advanced endometriosis — can be nociceptive (inflammation, adhesions) and/or neuropathic (central sensitization, allodynia, hyperalgesia) → neuropathic component to be systematically assessed (DN4 questionnaire); genital tract pain, lower back pain, cyclical sciatic pain (deep endometriosis involving the sciatic nerve — catamenial sciatica)
- Catamenial symptoms (cyclical, related to menstruation): Dyschezia (pain during defecation) + cyclic rectorrhagia (rectal or sigmoid endometriosis); dysuria + cyclic hematuria (vesical endometriosis); catamenial pneumothorax + cyclic hemoptysis (diaphragmatic or pulmonary endometriosis—rare); cyclic right shoulder pain (right diaphragmatic endometriosis—phrenic nerve irritation)
- Infertility 35–50 % of infertile women have endometriosis—multiple mechanisms: anatomical distortion of fallopian tubes and ovaries (adhesions), reduced ovarian reserve (endometriomas—destruction of healthy ovarian cortex during cyst formation + during surgical cystectomy), altered oocyte and embryo quality (pro-inflammatory cytokines in follicular fluid), impaired embryo implantation (endometrial inflammation + altered uterine receptivity); endometriosis is diagnosed in 25–50 % of women presenting with unexplained infertility
Diagnosis and treatment
| Appearance / Treatment | Mechanism, technique and procedures | Performances, duration, and precautions |
|---|---|---|
| Transvaginal pelvic ultrasound First intention — endometriomas and DIE |
Transvaginal ultrasound (TVUS) by an endometriosis-trained operator (specialized sonographer): first-line tool for the detection of ovarian endometriomas (cyst with homogeneous finely echogenic content — «ground glass» appearance — thickened wall — sensitivity 90–94 % + specificity 91–98 % for endometriomas >2 cm) and deep infiltrating endometriosis (DIE); sonographic signs of DIE: thickening of the uterosacral ligaments (irregular hypoechoic nodule), involvement of the rectovaginal septum, invasion of the rectal or sigmoid wall (loss of intestinal gliding — negative sliding sign — movement to the right or left); bladder endometriosis: hypoechoic nodule of the posterior bladder wall; transvaginal ultrasound with rectal gel instillation (EVGE): improves visualization of the rectum and rectovaginal septum | Standard ultrasound does not exclude superficial peritoneal endometriosis (implants too small to be detected) or mild to moderate forms—a negative result should not delay diagnosis in a symptomatic patient; in Quebec clinical practice: ultrasound available in GMF-U, hospital centers, and private clinics—waiting time varies—priority access recommended for suspected endometriosis with infertility or DIE; pelvic MRI (1.5 or 3 Tesla—endometriosis protocol with rectal preparation and bladder filling): superior to ultrasound for mapping the extent of DIE (parametrial, ureteral, high rectal, sigmoid colon involvement) + essential preoperative assessment before DIE surgery |
| Surgical Diagnosis — Laparoscopy Gold standard — histological confirmation |
Diagnostic laparoscopy with biopsies of implants and histopathological analysis (presence of endometrial glands and/or stroma) remains the gold standard for diagnosing endometriosis—sensitivity 97% + specificity 77% in experienced hands; rASRM (revised American Society for Reproductive Medicine) classification: stages I (minimal—1–5 points) to IV (severe—>40 points) according to the number, size, and depth of implants + degree of adhesions; limitations: rASRM classification correlates poorly with symptom severity and fertility prognosis; current trend toward avoiding diagnostic laparoscopy alone and combining diagnosis and surgical treatment simultaneously (one-step approach); presumptive clinical diagnosis (without laparoscopy) is increasingly accepted to initiate empirical hormonal treatment if the presentation is typical and imaging is compatible—ESHRE 2022 | Histological diagnosis is recommended for any operated lesion (confirmation of endometriosis + exclusion of malignant transformation – rare but possible in endometriomas – endometrioid carcinoma or clear cell carcinoma of the ovary); serum CA-125 marker: not recommended as a diagnostic tool (low sensitivity for stages I–II, non-specific elevation – also present in ovarian cancers, adenomyosis, fibroids, pregnancy) – may be used for postoperative follow-up in cases of deep endometriosis; preoperative assessment of DIE: TVE + pelvic MRI + colonoscopy or barium enema if symptomatic rectal involvement (dyschezia, rectal bleeding) + cystoscopy if bladder involvement + ureteral assessment (uroCT or uroMRI) if lateral DIE with risk of ureteral stenosis |
| Hormone therapy — 1st and 2nd line Suppression of endogenous estrogen — pain treatment |
Combined oral contraceptives (COCs) continuously (without a break week): First line — reduction of dysmenorrhea and pelvic pain in 70–80 % of cases — mechanism: ovulation suppression + atrophy of endometriotic implants + reduction of menstrual flow + anti-inflammatory effects of progestins; Progestin-only pills: Dienogest (Visanne) 2 mg/day orally — norethindrone-derived progestin — direct anti-proliferative effect on endometriotic implants + anti-angiogenic — very effective for dysmenorrhea and pelvic pain (NRS −4.5 vs −1.2 placebo — Strowitzki 2010) — ESHRE 2022 first line; Levonorgestrel-releasing intrauterine device (Mirena 52 µg/24h): comparable efficacy for dysmenorrhea + amenorrhea in 50 % of cases + contraception; Medroxyprogesterone acetate (Depo-Provera 150 mg IM × 1/3 months): option if injectable route is preferred | Hormone therapy suppresses symptoms but does not cure endometriosis — relapse upon stopping treatment in 50–80 % of cases; prolonged treatment recommended until menopause or desire for pregnancy («long-term» treatment — ESHRE 2022); adverse effects of dienogest: irregular spotting (frequent at the start of treatment — generally improves after 3–6 months), decreased libido, headaches, slight weight gain; COCs contraindicated: history of venous thromboembolism, migraine with aura, smoking >35 years old, uncontrolled hypertension, ischemic heart disease; GnRH analogues (leuprolide Lupron, nafarelin Synarel): 2nd line — profound hypoestrogenism → amenorrhea + implant atrophy — very effective but significant side effects (hot flashes, depression, bone loss — estrogen-progestogen add-back therapy recommended if >6 months) — reimbursed by RAMQ if first-line treatments fail |
| Pain relief and pain management Multimodal Approach — Nociceptive and Neuropathic Component |
NSAIDs: ibuprofen 400 mg 3 times/day or naproxen 500 mg 2 times/day – started 2-3 days before menses (prophylaxis) and continued during dysmenorrhea – prostaglandin inhibition → reduction of uterine contractions + local anti-inflammatory; acetaminophen 1 g 3-4 times/day: adjuvant – less effective alone but synergistic with NSAIDs; neuropathic pain (central sensitization – DN4 positive): amitriptyline 10-25 mg/evening (tricyclic antidepressant – central analgesic) or duloxetine 30-60 mg/day (SNRI – NeuropathyCanada) or pregabalin 75-150 mg/evening – to be discussed with the patient (side effects – drowsiness, weight gain); pelvic physiotherapy (pelvic floor physical therapy): treatment of dyspareunia and CPP – pelvic muscle hypertonicity common in endometriosis – increasing evidence of effectiveness; CBT psychotherapy: chronic pain + catastrophizing – improved quality of life | Chronic endometriosis pain often has a mixed component (nociceptive + neuropathic) after years of progression—systematically assess with DN4 and the Pain Catastrophizing Scale (PCS) questionnaire; central sensitization explains why some surgically treated patients with no residual implants continue to suffer—surgery alone is insufficient in these cases → multimodal approach is mandatory; opioids: avoid as much as possible in chronic endometriosis pain (risk of dependence + opioid-induced hyperalgesia + limited efficacy on neuropathic pain); Quebec Pain Management Program (PQDPC): recommended referral for patients with refractory chronic pain |
| Surgical treatment - excision and fertility Operative laparoscopy — specialized centers |
Conservative surgery (operative laparoscopy) by an endometriosis specialist gynecological surgeon: excision or vaporization of peritoneal implants; ovarian cystectomy (endometrioma stripping — maximal preservation of healthy ovarian tissue); DIE resection (uterosacral ligaments, rectovaginal septum, segmental colorectal resection if transmural rectal involvement, ureterolysis or bladder resection if urological involvement); adhesiolysis + restoration of pelvic anatomy; benefit on pain: 60–80% % reduction in dysmenorrhea and CPP after complete surgery (NRS −4 to −6) — recurrence at 5 years in 30–50 % without postoperative medical treatment → mandatory postoperative hormonal treatment to reduce relapses; benefit on fertility: improvement in spontaneous pregnancy rate after endometrioma excision (stages I–II) — NNT ≈ 8 (Cochrane Jacobson 2010) | Endometrioma cystectomy significantly reduces ovarian reserve (AMH - anti-Müllerian hormone) - discuss with the patient if she desires children (pre-operative ovarian reserve assessment: AMH + AFC - antral follicle count by ultrasound); for recurrent endometriomas, repeating cystectomy worsens the loss of ovarian reserve → prefer medical treatment or ultrasound-guided aspiration before IVF if immediate desire for pregnancy; radical surgery (hysterectomy + bilateral salpingo-oophorectomy): reserved for severe refractory endometriosis in patients with no desire for pregnancy - low operative mortality but significant morbidity in cases of extensive DIE (fistulas, ureteral stenosis, bladder dysfunction); certified endometriosis centers in Quebec: CHU de Québec (CHUL), CHUM, CHU Sainte-Justine - reference for complex DIE |
| Infertility and medically assisted reproduction PMA - IVF - fertility preservation |
Fertility work-up: AMH + CFA (ovarian reserve) + hysterosalpingography (HSG - tubal permeability) + partner spermogram + hormonal work-up (FSH, LH, estradiol D2-3); ovulation stimulation + intrauterine insemination (IUI): not very effective in moderate to severe endometriosis (cumulative pregnancy rate 8-15 % per cycle vs. 12-20 % in unexplained infertility); in vitro fertilization (IVF) + embryo transfer: reference treatment for infertility associated with endometriosis - pregnancy rate per transfer 25-40 % depending on age and oocyte quality - endometriotic patients respond less well to ovarian stimulation (fewer oocytes punctured) but pregnancy rate per oocyte is comparable to non-endometriotic women; fertility preservation (oocyte freezing): to be discussed with young patients with endometriomas or DIE before repeated ovarian surgery - RAMQ fertility preservation program (Bill 20 - Quebec) - IVF cycles reimbursed under certain conditions | The Quebec IVF program (Law 20 - 2015) reimburses up to 3 IVF cycles per woman (up to age 42) — eligibility criteria: failure of 3 IUI cycles (for those <36 years) or direct access to IVF (≥36 years or decreased ovarian reserve AMH <5 pmol/L); patients with endometriosis and low ovarian reserve (AMH 12 months without pregnancy for 6 months for ≥35 years or if a known infertility factor exists). |
ℹ️
Adenomyosis — often associated with endometriosis: Adenomyosis is the presence of endometrial tissue (glands and stroma) within the uterine myometrium (muscular wall of the uterus). It is distinct from extrauterine endometriosis but frequently associated (20–30 %of endometriosis patients also have adenomyosis). It manifests as menorrhagia, severe dysmenorrhea, and a globular, enlarged uterus. Diagnosis relies on pelvic MRI (junctional zone thickening >12 mm — sensitivity 77 % + specificity 89 % ) or transvaginal ultrasound (heterogeneous uterus, striated myometrium, myometrial cysts) by an experienced operator. Medical treatment (Mirena IUD, dienogest, GnRH analogs) is similar to that for endometriosis. Surgery (hysterectomy) is curative but definitive.
Situations requiring a prompt consultation
Consult a doctor quickly Within days if you present: Severe acute pelvic pain outside of menstruation in a patient with known endometriosis — consider a ruptured endometriotic cyst or ovarian torsion (surgical emergency); ; fever + pelvic pain — suggest a superinfection of a cyst or associated pelvic infection.
Seek emergency care if: Intense localized pain + nausea + vomiting (Ovarian torsion on endometrioma — surgical emergency within 6 hours to preserve the ovary); ; Severe dyschezia + abundant rectal bleeding (complication from deep rectal endometriosis).
Visit Debilitating dysmenorrhea unresponsive to NSAIDs in an adolescent or young woman is an indication for medical consultation for endometriosis assessment — do not dismiss it.
Consult at Clinique Omicron
Clinique Omicron physicians evaluate women presenting with disabling dysmenorrhea, chronic pelvic pain, or suspected endometriosis—this includes clinical examination, prescription of transvaginal pelvic ultrasound, initiation of first-line hormonal treatment, referral to specialized gynecology or endometriosis centers for complex cases, and coordination with fertility teams. Consultations are available at our service points in Quebec and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
The content of this page is provided for informational purposes only and does not substitute for the advice of a qualified healthcare professional. Any severe acute pelvic pain requires urgent medical evaluation to exclude ovarian torsion or another surgical complication.
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