How should the estradiol 208 pg/mL, progesterone 1.2 ng/mL, follicle‑stimulating hormone 8.8 IU/L, and luteinizing hormone 3.5 IU/L results be interpreted in a 48‑year‑old woman?

Hormone Interpretation in a 48-Year-Old Woman

These hormone levels indicate a perimenopausal transition with evidence of diminished ovarian reserve but preserved follicular activity, and the low progesterone suggests either anovulation or measurement outside the mid-luteal phase. 1

Key Findings Analysis

FSH Elevation Signals Perimenopause

• The FSH of 8.8 IU/L, while below the classic menopausal threshold, is elevated for a reproductive-age woman and indicates diminished ovarian reserve. 1
• FSH >10 IU/L definitively indicates diminished ovarian reserve, but levels between 8-10 IU/L in women over 40 years represent early decline. 1
• Research demonstrates that FSH rises progressively in the years preceding menopause (starting in the early 40s), while LH remains relatively normal—exactly the pattern seen here with FSH 8.8 and LH 3.5. 2, 3

Estradiol Remains Adequate

• The estradiol of 208 pg/mL (approximately 763 pmol/L) is within normal follicular phase range (51-601 pg/mL) and indicates maintained ovarian estrogen production despite declining follicular reserve. 4
• This preserved estradiol despite elevated FSH is characteristic of the perimenopausal transition, where remaining follicles continue to produce estrogen even as their numbers decline. 2, 3
• Estradiol below 20 pg/mL would suggest premature ovarian insufficiency, but this patient's level is nearly 10-fold higher, ruling out that diagnosis. 4

Progesterone Interpretation Requires Timing Context

• The progesterone of 1.2 ng/mL (approximately 3.8 nmol/L) is below the ovulatory threshold of 6 nmol/L, indicating either anovulation or measurement during the follicular phase rather than mid-luteal phase. 1
• Mid-luteal progesterone (measured 7 days after suspected ovulation) is the only reliable hormonal indicator of ovulation. 1
• Without knowing the cycle day of measurement, this low progesterone cannot definitively confirm anovulation—it may simply reflect follicular phase timing. 1
• Perimenopausal women commonly experience declining luteal progesterone even with continued ovulation, as demonstrated in women aged 40-50 years. 2

LH:FSH Ratio Assessment

• The LH:FSH ratio is 0.4 (3.5/8.8), which is inverted from the typical reproductive-age pattern and rules out PCOS (which requires LH:FSH >2). 1
• This inverted ratio with relatively higher FSH than LH is pathognomonic for the perimenopausal transition. 3

Clinical Significance at Age 48

This 48-year-old woman is in active perimenopause with:

• Declining but not depleted ovarian reserve (FSH approaching but not exceeding 10 IU/L)
• Maintained estrogen production from remaining follicles
• Possible anovulatory cycles or irregular ovulation (based on low progesterone if measured appropriately)
• Expected hormonal pattern for her age, as FSH elevation begins several years before final menstrual period 2, 3

Critical Next Steps

Confirm Ovulatory Status

• Repeat progesterone measurement specifically during mid-luteal phase (cycle day 21 for 28-day cycles, or 7 days after suspected ovulation) to definitively assess ovulation. 1
• Progesterone ≥6 nmol/L confirms ovulation occurred; <6 nmol/L indicates anovulation. 1

Monitor Menstrual Pattern

• Document cycle length and regularity, as increasing cycle variability is characteristic of perimenopause. 3
• Cycles may alternate between ovulatory and anovulatory, with variable estrogen withdrawal bleeding. 3

Additional Evaluation if Symptomatic

• Assess for vasomotor symptoms (hot flashes), sleep disturbance, or vaginal dryness that may warrant hormone therapy consideration. 5
• Check thyroid function (TSH) and prolactin if menstrual irregularities are present, as these can mimic perimenopausal patterns. 1

Common Pitfalls to Avoid

• Do not diagnose menopause based on a single FSH measurement—FSH can fluctuate significantly during perimenopause, and definitive menopause requires 12 months of amenorrhea. 3
• Do not interpret progesterone without knowing precise cycle timing—random progesterone measurements are meaningless for assessing ovulation. 1
• Do not assume fertility is absent—ovulation may still occur intermittently during perimenopause, and contraception remains necessary if pregnancy is undesired. 3
• Avoid measuring hormones in women using hormonal contraceptives, as these suppress the pituitary-ovarian axis and render results uninterpretable. 1