6.2 Contraception & Menopause

Contraception & Menopause

Providing evidence-based contraceptive counseling and managing menopausal symptoms are essential responsibilities in general practice. Clinicians must master the contraindications of estrogen-containing contraceptives, the clinical profile of long-acting reversible contraceptives (LARCs), emergency contraception options, and the indications and risks associated with Hormone Replacement Therapy (HRT).

1. Combined Oral Contraceptives (COCs) and Estrogen-containing Methods

Combined hormonal contraceptives include combined oral contraceptive (COC) pills, transdermal patches, and vaginal rings. They contain both an estrogen component (typically ethinyl estradiol) and a progestin component.

Mechanism of Action

• Estrogen: Suppresses Follicle-Stimulating Hormone (FSH) secretion from the anterior pituitary, which prevents the selection and development of a dominant follicle.
• Progestin: Suppresses Luteinizing Hormone (LH) secretion, preventing the LH surge and thereby inhibiting ovulation. It also thickens cervical mucus (impaired sperm penetration) and thins the endometrium (preventing implantation).

Contraindications (WHO Medical Eligibility Criteria Category 4)

Estrogen increases hepatic synthesis of clotting factors (factors VII, X, and fibrinogen) and decreases antithrombin III, raising the risk of thromboembolic events. The following are absolute contraindications (Category 4: unacceptable health risk) for combined hormonal contraceptives:

• Age ≥ 35 years and smoking ≥ 15 cigarettes/day: High risk of myocardial infarction and stroke.
• Hypertension: Systolic BP ≥ 160 mmHg or diastolic BP ≥ 100 mmHg, or hypertension with vascular disease.
• Venous Thromboembolism (VTE): History of or current deep vein thrombosis (DVT) or pulmonary embolism (PE).
• Known Thrombogenic Mutations: Such as Factor V Leiden, Prothrombin G20210A mutation, Protein S, Protein C, or Antithrombin deficiencies.
• Ischemic Heart Disease or Stroke: Current or history.
• Migraine with Aura: At any age. Estrogen-containing methods are contraindicated due to a significantly elevated risk of ischemic stroke (up to a 2- to 4-fold increase compared to non-users).
• Breast Cancer: Current breast cancer (estrogen is a growth promoter).
• Liver Disease: Severe cirrhosis, active viral hepatitis, or benign or malignant liver tumors (adenoma or hepatoma).
• Breastfeeding: Less than 21 days postpartum (increased VTE risk).

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2. Long-Acting Reversible Contraception (LARC)

LARC methods are the most effective reversible contraceptive options because their efficacy does not depend on patient compliance. They have typical-use failure rates of less than 1% per year.

Intrauterine Devices (IUDs)

1. Levonorgestrel-Releasing IUD (LNG-IUD):
   • Duration: Approved for 3 to 8 years depending on the specific device (e.g., Mirena, Kyleena).
   • Mechanism: Thickens cervical mucus, prevents sperm motility and fertilization, and causes endometrial atrophy.
   • Non-contraceptive Benefits: Approved for the treatment of heavy menstrual bleeding (menorrhagia) and dysmenorrhea. It reduces menstrual blood loss by up to 90%, and many women achieve amenorrhea after 1 year.
2. Copper IUD (Cu-IUD - ParaGard):
   • Duration: Approved for up to 10 years.
   • Mechanism: The release of copper ions creates a sterile local inflammatory reaction in the endometrium that is toxic to sperm and prevents fertilization. It is entirely hormone-free.
   • Side Effects: Can increase menstrual bleeding (menorrhagia) and cramping (dysmenorrhea), particularly during the first 3–6 months.
   • Emergency Contraception: The copper IUD can be inserted within 5 days (120 hours) of unprotected intercourse as the most effective form of emergency contraception (> 99% efficacy).

Subdermal Implant (Etonogestrel implant - Nexplanon)

• Duration: Approved for 3 years.
• Mechanism: Releases etonogestrel (a progestin) which primary acts by suppressing ovulation and thickening cervical mucus.
• Side Effects: Irregular, unpredictable breakthrough bleeding is the most common side effect and the primary reason for early discontinuation. Clinicians should counsel patients on this possibility pre-insertion.

LARC Risks and Complications

• Uterine Perforation: Occurs in approximately 1 in 1000 insertions, usually during the procedure.
• Expulsion: Occurs in 2–10% of users in the first year, more common in adolescents and nulliparous women.
• Infection: Pelvic Inflammatory Disease (PID) risk is slightly elevated only during the first 20 days post-insertion, related to the insertion technique. Thereafter, the risk returns to baseline.

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3. Emergency Contraception (EC)

Emergency contraception is indicated after unprotected intercourse, incorrect contraceptive use, or sexual assault. Three primary methods are available:

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4. Menopause and Hormone Replacement Therapy (HRT)

Menopause is clinically defined as permanent cessation of menstruation, diagnosed retrospectively after 12 consecutive months of amenorrhea without another pathological cause. It results from the depletion of ovarian follicles, leading to a marked decrease in estradiol levels and a compensatory increase in Follicle-Stimulating Hormone (FSH > 30 IU/L).

Indications for HRT

• Moderate-to-severe vasomotor symptoms (hot flashes, night sweats).
• Genitourinary syndrome of menopause (vaginal dryness, dyspareunia, urinary urgency).
• Prevention of postmenopausal osteoporosis in women at high risk of fractures who cannot tolerate non-estrogen therapies.

HRT Regimen Selection: The Crucial Clinical Rule

• Intact Uterus: The patient MUST receive combined Estrogen and Progestogen therapy. Unopposed estrogen therapy in a woman with a uterus leads to endometrial proliferation, significantly increasing the risk of endometrial hyperplasia and endometrial adenocarcinoma. Progestogen is added to counteract this risk.
• Post-Hysterectomy: The patient should receive Estrogen-only therapy. Progestogen is unnecessary and should be avoided to prevent associated breast cancer and cardiovascular risks.

Risks and Benefits Profile of HRT

The safety profile of HRT depends heavily on the patient's age and time since menopause (the timing hypothesis):

• Cardiovascular Disease and Stroke:
  • Initiating HRT before age 60 or within 10 years of menopause is associated with a favorable safety profile and may reduce coronary heart disease mortality (decreased plaque accumulation).
  • Initiating HRT after age 60 or > 10–20 years from menopause increases the risk of coronary heart disease, stroke, and venous thromboembolism (VTE).
• Breast Cancer:
  • Combined HRT (estrogen + progestogen) increases the risk of breast cancer after 3 to 5 years of continuous use. The risk is duration-dependent and decreases after stopping therapy.
  • Estrogen-only HRT does not increase the risk of breast cancer over a duration of 7 years of use.
• Venous Thromboembolism (VTE):
  • Oral HRT increases VTE risk due to hepatic first-pass metabolism, which stimulates the synthesis of clotting factors.
  • Transdermal Estrogen bypasses hepatic first-pass metabolism and does not increase VTE risk. It is the preferred route for women with risk factors such as obesity, controlled hypertension, or tobacco use.