At what age should women discontinue oral contraceptive (OC) pills?

When to Stop Birth Control Pills in Women

Women should continue using oral contraceptive pills until menopause or age 50-55 years if they wish to prevent pregnancy, as fertility can persist until age 51. 1

Understanding Fertility in Perimenopausal Women

The need for continued contraception in older women is based on several key facts:

• The median age of menopause is approximately 51 years in North America but can vary from 40 to 60 years 2, 1
• The median age of definitive loss of natural fertility is 41 years but can range up to age 51 years 2, 1
• Spontaneous pregnancies, although uncommon, do occur in women over 44 years of age 2, 1
• No reliable laboratory tests are available to confirm definitive loss of fertility in a woman 2
• Assessment of follicle-stimulating hormone levels to determine fertility status may not be accurate 2

Risks of Pregnancy vs. Contraception in Older Women

Pregnancy Risks in Advanced Age

Pregnancies in women over 44 years carry significantly higher risks:

• Maternal complications: hemorrhage, venous thromboembolism, and death 2, 1
• Fetal complications: spontaneous abortion, stillbirth, and congenital anomalies 2, 1

Contraception Risks in Older Women

The risks associated with continuing contraception must be weighed against pregnancy risks:

1. Venous Thromboembolism (VTE):

   • Higher incidence in women aged ≥45 years compared to younger users 2, 1
   • Risk is highest in the first year of use (OR: 4.17) and reduces to 2.76 over baseline after 4 years 3

2. Myocardial Infarction:

   • Higher relative risk among all OC users than non-users 2, 1
   • Risk does not correlate to length of therapy and disappears after treatment termination 3

3. Stroke:

   • Combined hormonal contraceptives increase risk of thrombotic stroke by 50-100% 4

4. Breast Cancer:

   • Small but nonsignificant increased relative risks for breast cancer among women who used oral contraceptives when aged ≥40 years 2, 1

Contraceptive Options for Women Over 45

According to U.S. Medical Eligibility Criteria (MEC):

• Women aged >45 years can safely use (U.S. MEC 1):

  • Progestin-only pills (POPs)
  • Implants
  • Levonorgestrel IUD
  • Copper IUD 2, 1

• Women aged >45 years generally can use (U.S. MEC 2):

  • Combined hormonal contraceptives
  • DMPA (depot medroxyprogesterone acetate) 2

Risk Factors Requiring Special Consideration

Women should be evaluated for risk factors that might make hormonal contraception unsafe:

• Smoking: Increases risk of myocardial infarction 10-fold in OC users 3
• Hypertension: Poorly controlled hypertension increases risk of myocardial infarction and ischemic stroke approximately 3-fold, and hemorrhagic stroke 15-fold 3
• Multiple cardiovascular risk factors: Consider progestogen-only contraceptives (POCs) which are associated with substantially less risk of cardiovascular events than combined oral contraceptives 3
• Thrombophilia: Women with factor V Leiden, prothrombin G20210A, or blood group non-O have further increased risk when using hormonal contraception 5

Practical Approach to Discontinuation

1. Continue contraception until confirmed menopause or age 50-55 years if pregnancy prevention is desired 2, 1
2. For women with cardiovascular risk factors, consider switching to non-hormonal methods or progestin-only options after age 45 3, 4
3. If fertility assessment is needed, discontinue OCPs for at least 1-3 months to allow return of normal hypothalamic-pituitary-ovarian function 1

Common Pitfalls to Avoid

• Stopping contraception too early: Assuming infertility before confirmed menopause can result in unintended pregnancy
• Ignoring individual risk factors: Cardiovascular risk factors significantly increase the risks associated with combined hormonal contraceptives
• Failing to consider alternatives: Non-oral hormone therapy appears to have a more favorable risk profile with no increased risk of venous thrombosis 5

Remember that both the American College of Obstetricians and Gynecologists and the North American Menopause Society recommend continuing contraception until menopause or age 50-55 years if pregnancy prevention is desired 2, 1.