15.1 Endometriosis & Adenomyosis

Benign pelvic conditions and urogynecologic disorders represent a substantial proportion of ambulatory gynecologic visits across the female lifespan. From debilitating cyclic pelvic pain and abnormal uterine bleeding to pelvic floor relaxation, urinary incontinence, and adnexal masses, these conditions profoundly impact physical comfort, emotional well-being, sexual function, and daily living. Certified nurse-midwives provide primary diagnostic evaluation, initiate evidence-based conservative and medical therapies, manage pessaries, and discern clinical red flags requiring collaborative surgical consultation or oncology referral.

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Endometriosis: Pathophysiology, Presentation & Stepwise Management

Endometriosis is defined as the presence of functional endometrial glands and stroma outside the uterine cavity, predominantly located on pelvic peritoneum, ovaries, uterosacral ligaments, and the rectovaginal septum.

Pathophysiological Mechanisms

• Retrograde Menstruation (Sampson's Theory): Transtubal reflux of viable desquamated menstrual endometrium into the peritoneal cavity during menses occurs in >90% of women. In susceptible individuals, defective peritoneal immunosurveillance allows ectopic tissue implantation.
• Coelomic Metaplasia: Transformation of pluripotent peritoneal mesothelial cells into functional endometrial-like glandular tissue under chronic inflammatory, hormonal, or environmental stimuli.
• Vascular & Lymphatic Dissemination (Halban's Theory): Transport of endometrial cells through pelvic venous channels and lymphatics, explaining distant extra-pelvic locations (pleura, umbilicus, surgical scars).
• Immune Clearance Dysfunction & Local Steroidogenesis: Impaired natural killer (NK) cell cytotoxicity and defective macrophage phagocytosis fail to clear ectopic debris. Ectopic implants express high levels of aromatase, producing continuous local estradiol that drives chronic neurogenic inflammation, cytokine upregulation (IL-1, IL-6, TNF-alpha, VEGF), angiogenesis, and progressive fibrosis.

Classic Clinical Presentation

Endometriosis is classically characterized by the "4 Ds":

1. Dysmenorrhea: Severe, secondary, crampy pelvic pain that typically begins several days prior to menses, worsens throughout flow, and responds poorly to over-the-counter analgesics.
2. Dyspareunia: Deep pelvic pain during or following penetrative vaginal intercourse, resulting from stretching of scarred uterosacral ligaments or the obliterated pouch of Douglas.
3. Dyschezia: Painful defecation, often cyclic and worsening during menstrual flow, reflecting rectovaginal or rectosigmoid peritoneal involvement.
4. Dysuria: Cyclic burning, urgency, or bladder pain during menses without documented bacterial infection.

• Additional Manifestations: Chronic non-cyclic pelvic pain (>6 months), cyclic catamenial gastrointestinal symptoms (bloating, diarrhea, constipation), and subfertility or infertility (present in 30% to 50% of affected women).

[!CRITICAL] AMCB Clinical Pearl — Lack of Stage Correlation: The revised American Society for Reproductive Medicine (rASRM) staging system (Stage I: Minimal, Stage II: Mild, Stage III: Moderate, Stage IV: Severe) is based solely on anatomical lesion distribution and adhesive extent. The laparoscopic stage does NOT correlate with the severity of pain symptoms or disability. A patient with minimal peritoneal implants (Stage I) may suffer excruciating, disabling pain, while a woman with extensive frozen pelvis and bilateral large endometriomas (Stage IV) may be completely asymptomatic.

Physical Examination & Diagnostic Evaluation

• Physical Exam Findings: Bimanual and rectovaginal examination may demonstrate palpable tender nodularity along the uterosacral ligaments, induration of the cul-de-sac (pouch of Douglas), a fixed, retroverted, immobile uterus (secondary to posterior pelvic dense adhesions), and tender, enlarged, fixed adnexal masses (endometriomas).
• Transvaginal Ultrasound (TVUS): First-line imaging modality. TVUS is highly sensitive for detecting ovarian endometriomas ("chocolate cysts"), which characteristically appear as unilocular or multilocular cystic lesions with homogeneous, low-level internal echoes ("ground-glass" appearance) and absent vascular flow on color Doppler. Normal ultrasound does NOT rule out peritoneal endometriosis.
• Definitive Gold Standard Diagnosis: Direct visualization via diagnostic laparoscopy with histologic confirmation of endometrial glands and stroma. However, current clinical guidelines strongly endorse initiating empiric medical therapy without requiring prior surgical laparoscopy in patients with a suggestive clinical history.

Stepwise Medical Management Cascade for Endometriosis
├── First-Line Empiric Medical Therapy (Initiate without laparoscopy)
│   ├── 1. Scheduled NSAIDs (Naproxen 500 mg BID or Ibuprofen 800 mg TID)
│   └── 2. Continuous Hormonal Suppression
│       ├── Combined Oral Contraceptives (continuous active pills without placebo)
│       ├── Norethindrone Acetate (Aygestin, 5 to 15 mg PO daily)
│       ├── Depot Medroxyprogesterone Acetate (DMPA, 150 mg IM q13w)
│       └── 52 mg Levonorgestrel IUD (Mirena - profound local decidualization)
└── Second-Line Medical Therapy (Refractory to first-line agents)
    ├── GnRH Agonists (Leuprolide acetate 3.75 mg IM monthly or 11.25 mg q3m)
    │   └── MANDATORY: Norethindrone acetate 5 mg/day "Add-Back" therapy
    └── Oral GnRH Antagonists (Elagolix 150 mg daily or 200 mg BID)
        └── Suppresses pituitary gonadotropins; dose-dependent estrogen suppression

• Surgical Management: Indicated for severe intractable pain refractory to medical therapy, advanced deep infiltrating endometriosis affecting bowel or ureters, large endometriomas (>3 to 4 cm), or treatment of endometriosis-associated infertility. Involves laparoscopic excision or ablation of implants and endometrioma cystectomy (stripping the cyst wall rather than drainage/cautery to reduce recurrence and preserve ovarian reserve).

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Adenomyosis: Clinical Recognition & Management

Adenomyosis is a benign uterine disorder characterized by the presence of heterotopic endometrial glands and stroma embedded within the myometrium, surrounded by reactive compensatory myometrial smooth muscle hyperplasia and hypertrophy.

Clinical Features & Demographics

• Epidemiology: Most commonly diagnosed in multiparous women in their late 30s and 40s (40 to 50 years); associated with parity and prior uterine surgery (cesarean delivery, endometrial curettage).
• Symptom Profile: Heavy menstrual bleeding (menorrhagia / HMB) in ~60% of cases (due to increased uterine cavity surface area, altered myometrial vascular architecture, and impaired myometrial contractility), severe secondary dysmenorrhea in ~30%, chronic dull pelvic aching, and deep dyspareunia. Approximately one-third of women are asymptomatic.
• Physical Examination Findings: Bimanual examination reveals a symmetrically enlarged, soft, boggy, globally tender "globular" uterus, typically 10 to 14 weeks gestational size. Critically, unlike the fixed, retroverted uterus of endometriosis, the adenomyotic uterus is freely mobile.

Diagnostic Modalities & Treatment

• Transvaginal Ultrasound (TVUS): First-line imaging. Diagnostic criteria include: asymmetrical myometrial thickening (predominantly posterior wall), subendometrial myometrial cysts (hypoechoic lacunae representing cystic dilatation of ectopic glands), subendometrial echogenic linear striations ("rain on a lake" / fan-shaped acoustic shadowing), and indistinct or disrupted endometrial-myometrial junctional zone (JZ).
• Magnetic Resonance Imaging (MRI): Highly accurate. A thickened junctional zone ≥12 mm on T2-weighted MRI is diagnostic of adenomyosis (normal JZ is <8 mm).
• Clinical Management:
  • First-Line Medical Therapy: 52 mg Levonorgestrel IUD (Mirena) is the most effective medical treatment; local intrauterine progestin release produces profound decidualization and endometrial atrophy, reducing menstrual blood loss by >70% to 90% and alleviating dysmenorrhea. Alternative medical options include continuous oral progestins, DMPA, or tranexamic acid/NSAIDs during menses.
  • Definitive Surgical Therapy: Total hysterectomy (with ovarian preservation) provides complete definitive cure for women who have completed childbearing and fail medical management.

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