What do follicular count of 11, estradiol (E2) level of 24 pg/mL, and follicle-stimulating hormone (FSH) level of 5.6 milli-international units per milliliter (mIU/mL) signal for ovarian reserve 2.5 years after unilateral oophorectomy?

Ovarian Reserve Assessment After Unilateral Oophorectomy

These results indicate diminished ovarian reserve with a follicular count of 11 and low estradiol at 24 pg/mL, though the FSH of 5.6 mIU/mL remains in the normal range, suggesting the remaining ovary is still responding but with significantly reduced functional capacity.

Interpretation of Individual Parameters

Antral Follicle Count (AFC = 11)

• An AFC of 11 falls in the low-normal to diminished range, particularly concerning after unilateral oophorectomy where you would expect roughly half the baseline follicle count 1
• AFC is one of the most reliable markers of ovarian reserve and correlates directly with the number of oocytes that can be retrieved during assisted reproductive technology 2
• This count suggests limited but not absent ovarian reserve 3

Estradiol (E2 = 24 pg/mL)

• This estradiol level is notably low for early follicular phase, indicating reduced follicular activity and estrogen production 4
• Low estradiol in the context of normal FSH suggests the ovary is producing fewer follicles capable of adequate estrogen synthesis 2
• This pattern is consistent with diminished ovarian reserve where follicular quality and quantity are both compromised 1

FSH (5.6 mIU/mL)

• The FSH remains within normal range (typically <10 mIU/mL is considered normal), which initially appears reassuring 4
• However, FSH alone is an inadequate marker of ovarian reserve, particularly in younger women or those with recent ovarian surgery 2
• The combination of low AFC and low estradiol despite normal FSH suggests early diminished reserve that has not yet triggered compensatory FSH elevation 3

Clinical Context: Post-Unilateral Oophorectomy

Expected Changes After Unilateral Oophorectomy

• Women who undergo unilateral oophorectomy have reduced ovarian reserve and greater risk of premature ovarian failure compared to controls 4
• Unilateral oophorectomy is associated with elevated FSH levels even when one ovary remains, though the effect is smaller than bilateral oophorectomy 5
• At 2.5 years post-surgery, the remaining ovary may show signs of accelerated follicular depletion 5

Prognostic Implications

For fertility potential:

• Women with diminished ovarian reserve (suggested by AFC <15 and low estradiol) should pursue fertility evaluation and attempts promptly 6
• The combination of low AFC and low estradiol indicates reduced oocyte yield if assisted reproductive technology is pursued 4
• There may be a modestly increased miscarriage risk associated with diminished ovarian reserve, though evidence remains mixed 4, 6

For reproductive lifespan:

• These findings suggest accelerated ovarian aging and increased risk of earlier menopause 1
• The patient should be counseled about potential for premature ovarian insufficiency given the surgical history and current reserve markers 4

Recommended Management Approach

Immediate Actions

• Add anti-Müllerian hormone (AMH) testing to complete the ovarian reserve assessment, as AMH is the best endocrine marker for age-related decline in ovarian reserve and does not vary by menstrual cycle day 6, 1
• Obtain patient's age, as interpretation of these values is highly age-dependent (more concerning if <35 years) 6
• Document menstrual cycle regularity, as irregular cycles with these findings may herald premature ovarian insufficiency 6

Counseling Points

• If future fertility is desired, referral to reproductive endocrinology should occur promptly given diminished reserve markers 6
• Discuss fertility preservation options including oocyte or embryo cryopreservation if pregnancy is not immediately planned 4
• Counsel regarding increased risk of premature ovarian failure and potential need for hormone replacement therapy 4

Monitoring Strategy

• Serial monitoring of FSH, estradiol, and AMH every 6-12 months to track rate of ovarian reserve decline 4
• Monitor for symptoms of estrogen deficiency (hot flashes, vaginal dryness, mood changes) 4
• Consider bone mineral density screening if signs of hypoestrogenism develop 4

Common Pitfalls to Avoid

• Do not rely on FSH alone as a marker of adequate ovarian reserve—the combination of AFC and estradiol provides more accurate assessment 2
• Do not falsely reassure based on normal FSH when AFC and estradiol indicate diminished reserve 1
• Do not delay fertility counseling in women with these findings who desire future pregnancy, as ovarian reserve may decline rapidly 6
• Ensure AMH assay results are interpreted using laboratory-specific reference ranges, as different assays yield varying results 6