Does oral contraception (OC) affect the menopause transition?

Oral Contraception's Effect on Menopause Transition

Oral contraception does not affect the timing of menopause but masks perimenopausal symptoms and requires continued use until confirmed menopause, typically until age 50-55, as no reliable laboratory tests can confirm definitive loss of fertility. 1

Impact on Menopausal Transition

Oral contraceptives (OCs) primarily impact the perimenopausal experience in the following ways:

• Symptom Masking: OCs suppress the natural hormonal fluctuations of perimenopause, effectively masking symptoms like hot flashes and irregular bleeding that would otherwise signal the transition 2
• Fertility Assessment Challenges: Women using OCs cannot accurately assess their menopausal status while on the medication, as the synthetic hormones suppress natural ovarian function 3
• Diagnostic Difficulties: No reliable laboratory tests can confirm definitive loss of fertility in women using OCs, making it difficult to determine when menopause has occurred 1

Determining When Menopause Has Occurred

For women using oral contraceptives during perimenopause, determining true menopausal status requires:

• Discontinuation Period: OCs must be discontinued for at least 1-3 months to allow return of normal hypothalamic-pituitary-ovarian function before fertility assessment 1
• Hormone Testing: After discontinuation, FSH levels can be measured, though these are not always definitive 3
• Clinical Indicators: After OC discontinuation, lack of increase in estradiol levels and/or substantially increased FSH levels may indicate menopause has occurred 3

Recommendations for Perimenopausal OC Use

• Continue Until Age 50-55: The American College of Obstetricians and Gynecologists, the North American Menopause Society, and the CDC/WHO guidelines recommend continuing contraception until menopause is confirmed or age 50-55 years 1
• Low-Dose Formulations: Women aged >45 years generally can use combined hormonal contraceptives but should be evaluated for cardiovascular risk factors 1
• Alternative Options: For women with risk factors, progestin-only methods (pills, implants, levonorgestrel IUD) and copper IUDs are safer alternatives 1

Benefits of OC Use During Perimenopause

Oral contraceptives offer several benefits for perimenopausal women:

• Menstrual Regulation: OCs regularize menses in women with perimenopausal dysfunctional uterine bleeding, reducing the need for surgical intervention 2
• Bone Health: OC use by women in their 40s has been found to decrease the risk of postmenopausal hip fractures 2
• Cancer Risk Reduction: OCs reduce long-term risk of endometrial and ovarian cancers 2
• Symptom Relief: Good evidence shows that OCs relieve vasomotor symptoms in perimenopausal women 2

Risks and Considerations

• Cardiovascular Risk: Women aged ≥45 years have a higher baseline incidence of venous thromboembolism compared to younger women, though the interaction between hormonal contraception and age doesn't significantly increase this risk beyond baseline 1
• Cancer Risk: There is a small but nonsignificant increased relative risk for breast cancer among women who used oral contraceptives when aged ≥40 years 1
• Smoking: Smoking significantly increases cardiovascular risks with OC use in older women 4

Transitioning to Hormone Replacement Therapy

When transitioning from OCs to hormone replacement therapy (HRT):

• Discontinuation Protocol: Stop OCs for 1-2 weeks to assess menopausal status 3
• Diagnostic Indicators: After discontinuation, elevated FSH levels and/or no change in basal estradiol levels strongly suggest it's safe to switch from OCs to standard hormone replacement regimens 3
• Timing Considerations: The transition should typically occur around age 50-55, but should be individualized based on symptoms and risk factors 1

Common Pitfalls to Avoid

• Premature Discontinuation: Stopping contraception too early can result in unintended pregnancy, as fertility can persist into the late 40s 1
• Relying on Symptoms: Assuming menopause has occurred based on symptoms while still on OCs is unreliable 3
• Inadequate Assessment: Failing to allow sufficient time off OCs before measuring hormone levels can lead to inaccurate assessment of menopausal status 3
• Overlooking Benefits: Discontinuing OCs without considering their non-contraceptive benefits (bone health, cancer prevention, symptom management) 2