What is the appropriate management for a 24‑year‑old woman trying to conceive who has normal estradiol, follicle‑stimulating hormone, luteinizing hormone, and prolactin levels?

Management of a 24-Year-Old Woman with Normal Hormone Levels Attempting Conception

This patient's hormone values are entirely normal for the early follicular phase and do not require any intervention; she should proceed with attempting natural conception while ensuring proper timing of intercourse and addressing any other potential fertility factors. 1, 2

Interpretation of Laboratory Values

The presented hormone levels fall within expected ranges for a reproductive-age woman:

• Estradiol 164.0 pg/mL: This is normal for the follicular phase, indicating adequate follicular activity and ovarian steroidogenic capacity 3
• FSH 5.6 mIU/mL: This is well below the threshold of 10 IU/L that would suggest diminished ovarian reserve, confirming adequate ovarian reserve and responsiveness to gonadotropin stimulation 3
• LH 2.99 mIU/mL: This is within normal range and does not suggest hypothalamic dysfunction (which would be <7 IU/mL) or PCOS (which typically shows LH:FSH ratio >2) 3
• Prolactin 15.5 ng/mL: This is normal; hyperprolactinemia (which accounts for approximately 20% of secondary amenorrhea cases) is not present 2

Critical Next Steps

Confirm Ovulation

Normal baseline hormones do not guarantee ovulation. 3 The most important missing piece of information is confirmation that this patient is actually ovulating:

• Mid-luteal progesterone measurement (day 21 of a 28-day cycle, or 7 days after presumed ovulation) is essential 1, 2
• Progesterone ≥6 nmol/L (approximately 8 ng/mL) confirms ovulation occurred 2, 3
• Values <6 nmol/L indicate anovulation despite normal baseline hormones 3

Additional Baseline Testing

Complete the standard infertility evaluation with:

• TSH screening: Routine thyroid screening is recommended because thyroid disorders directly affect fertility 2
• AMH measurement: Can be drawn on any day of the cycle and provides additional assessment of ovarian reserve; it is stable across menstrual phases and not altered by exogenous hormones 2, 3

Timeline for Evaluation

Given this patient's age (24 years), the standard recommendation applies:

• Evaluation after 12 months of regular unprotected intercourse for women under 35 years 2
• However, earlier evaluation is warranted if she has: 2
  • History of oligo-amenorrhea
  • Suspected uterine or tubal disease
  • Endometriosis
  • A partner known to be subfertile

Common Pitfalls to Avoid

Timing Errors

• These hormone levels appear to have been drawn appropriately (early follicular phase, days 2-5), but confirm the exact cycle day when they were obtained 1, 2
• If drawn outside days 2-5, interpretation may be unreliable 3

Incomplete Assessment

• Do not assume ovulation based solely on regular menses; anovulation can occur despite normal FSH, LH, and estradiol if measured only in the follicular phase 3
• Single hormone measurements may not be diagnostic; serial measurements may be needed in some cases 1

Medication Interference

• Confirm the patient is not using hormonal contraceptives, as hormone measurements during contraceptive use are not reliable for assessing ovarian function 1
• If recently discontinued, ideally wait 2 months after stopping hormonal contraceptives before testing 2, 3

When to Refer to Reproductive Endocrinology

Referral is appropriate when: 1

• Hormone levels are abnormal (not applicable in this case)
• Basic infertility evaluation is normal despite continued inability to conceive after 12 months
• Signs of ovarian dysfunction or abnormal hormone levels emerge
• Known risk factors for diminished ovarian reserve are present

Practical Recommendations for This Patient

1. Obtain mid-luteal progesterone to confirm ovulation 1, 2
2. Complete TSH screening 2
3. Consider AMH measurement for comprehensive ovarian reserve assessment 2
4. Optimize conception timing: Intercourse every 2-3 days throughout the cycle, or daily during the fertile window (approximately 5 days before ovulation through ovulation day)
5. Continue attempting natural conception for up to 12 months total (given her age <35 years) before pursuing further evaluation 2
6. Reassess at 12 months if not pregnant, or sooner if any concerning symptoms develop