Menopause Labs in Patients on Oral Contraceptives
No, you cannot reliably draw menopause labs (FSH) in a patient taking oral birth control pills, as the hormones suppress FSH levels and render the results uninterpretable for determining menopausal status. 1, 2
Why FSH Testing Is Unreliable on Oral Contraceptives
The exogenous hormones in oral contraceptives suppress the hypothalamic-pituitary-ovarian axis, which directly interferes with FSH measurement:
No reliable laboratory tests are available to confirm definitive loss of fertility in women using hormonal contraception—the assessment of follicle-stimulating hormone levels to determine when a woman is no longer fertile is not accurate in this context. 1, 2
Research demonstrates that combined oral contraceptives significantly suppress FSH levels compared to non-users (mean FSH 12.5 IU/mL in COC users versus 26.7 IU/mL in non-users), making interpretation impossible. 3
Even when FSH is measured during the pill-free interval (day 7 off pills), 62.5% of confirmed menopausal women still had FSH levels <30 mIU/mL, demonstrating poor sensitivity of this approach. 4
If You Need to Assess Menopausal Status
Option 1: Discontinue Oral Contraceptives Temporarily
Stop oral contraceptives for 2 weeks, then measure FSH and estradiol levels. 5
After two weeks off oral contraceptives, an elevated FSH and/or no change in basal estradiol levels provides strong evidence of menopause. 5
However, this approach leaves the patient without contraceptive protection during the testing period, which is problematic since contraceptive protection is still needed for patients aged >44 years who want to avoid pregnancy. 1
Option 2: Clinical Assessment Without Laboratory Testing
The most practical approach is to continue contraception until age 50-55 years or until 12 months of amenorrhea off all hormonal contraception, as recommended by both ACOG and the North American Menopause Society. 1, 2
The median age of menopause is approximately 51 years in North America (range 40-60 years). 1, 2
The median age of definitive loss of natural fertility is 41 years but can range up to 51 years. 1
Common Pitfalls to Avoid
Do not attempt to measure FSH while the patient is actively taking oral contraceptives—the results will be artificially suppressed and clinically meaningless. 4, 3
Do not assume fertility has ended before confirmed menopause (12 months without menses off all hormonal contraception), as unintended pregnancy remains possible and carries higher maternal and fetal complication risks at advanced reproductive age. 2, 6
Do not discontinue contraception based on age alone—pregnancies among women of advanced reproductive age are at higher risk for maternal complications (hemorrhage, venous thromboembolism, death) and fetal complications (spontaneous abortion, stillbirth, congenital anomalies). 1
Practical Recommendation
Continue oral contraceptives (or transition to a progestin-only method or IUD if cardiovascular risk factors develop) until age 50-55 years, then discontinue and observe for 12 months of amenorrhea to confirm menopause. 1, 2 This approach avoids the unreliable laboratory testing while ensuring adequate contraceptive protection during the perimenopausal transition.