Understanding Menopause and the Return of Periods

True menopause (12 consecutive months without menses) is irreversible naturally. Ovarian follicular depletion is permanent. However, "period-like" bleeding can occur postmenopausally and always warrants evaluation.

Menopause Definition & Physiology

• **Menopause:** Final menstrual period (FMP), confirmed retrospectively after 12 months amenorrhea. Average age 51–52.
• **Perimenopause:** Preceding years (4–8); erratic cycles, hormonal fluctuations.
• **Mechanism:** Ovarian follicle exhaustion → ↓ inhibin → ↑ FSH → ↓ estradiol/progesterone → endometrial atrophy.

Causes of Postmenopausal Bleeding (PMB) – Never Normal

• **Atrophy:** Vaginal/endometrial (most common) – fragile vessels bleed.
• **Endometrial Hyperplasia/Cancer:** **Must rule out** (risk ↑ with age, obesity, unopposed estrogen, tamoxifen).
• **Polyps/Fibroids:** Cervical or endometrial.
• **Hormone Therapy (HT):** Cyclic regimens induce withdrawal bleeds; continuous combined may cause spotting initially.
• **Medications:** Anticoagulants, tamoxifen.
• **Infection/Trauma:** Atrophic vaginitis, lichen sclerosus.
• **Other Malignancies:** Cervical, vaginal, vulvar.

Induced Bleeding (Not True Menses)

• **HT Withdrawal Bleeds:** Scheduled shedding on progestin-free interval.
• **Fertility Treatments:** Ovulation induction + progesterone withdrawal.
• **Diagnostic Progestin Challenge:** Confirms estrogenization.

Evaluation of PMB

1. **Transvaginal Ultrasound:** Endometrial thickness (ET) <4 mm → low cancer risk (NPV >99%). ET ≥4 mm → biopsy.
2. **Endometrial Biopsy / Hysteroscopy + D&C.**
3. **Cervical Cancer Screening** if due.

Key Message

**Any bleeding ≥12 months after last period requires prompt medical assessment.** Do not assume "period returned."