AMH vs FSH vs AFC: Which Fertility Test Do You Actually Need?

AMH, FSH, or AFC — which ovarian reserve test matters most? Compare all fertility tests, when to take each one, and how to read your results together.

Your doctor ordered AMH, FSH, and maybe an AFC ultrasound — but which test actually tells you the most about your fertility? And do you need all of them? Here's a clear breakdown of every ovarian reserve test, what each one measures, and how to read your results together so you walk into your appointment informed.

AMH vs FSH: Which Is More Important for Fertility?

AMH and FSH are both used to assess ovarian reserve, but they measure different things and behave differently throughout your cycle:

  • AMH is produced by small ovarian follicles and remains stable throughout your cycle — test any day
  • FSH (follicle-stimulating hormone) must be tested on cycle day 2-4 for accurate interpretation
  • AMH declines gradually with age, providing early warning of diminishing reserve
  • FSH rises as reserve declines — the brain sends stronger signals to stimulate fewer remaining follicles
  • Low AMH + High FSH together strongly indicate diminished ovarian reserve
  • Normal AMH + Normal FSH is reassuring but doesn't guarantee fertility

The AMH Analyzer accepts FSH as an optional input for a more comprehensive assessment. Adding your FSH value improves the accuracy of the multi-marker evaluation.

What Is Antral Follicle Count (AFC) and What's Normal?

AFC counts the small visible follicles on your ovaries via transvaginal ultrasound, typically on cycle day 2-5. It's the most direct real-time measure of ovarian reserve and strongly correlates with AMH. While AMH is a blood test reflecting overall reserve, AFC shows what's available in a given cycle. Combined, they provide the most accurate ovarian reserve assessment:

  • AFC > 15: High reserve — typically correlates with AMH > 2.5 ng/mL
  • AFC 10-15: Normal reserve — typical for women under 35
  • AFC 5-10: Below average — may indicate diminished reserve depending on age
  • AFC < 5: Low reserve — specialist consultation recommended

Do I Need an Estradiol (E2) Test for Fertility?

Day 3 estradiol is often tested alongside FSH. A normal estradiol level (<80 pg/mL on day 3) validates the FSH reading. If estradiol is elevated early in the cycle, it may artificially suppress FSH, masking diminished reserve. An elevated day 3 estradiol combined with a 'normal' FSH can actually be a warning sign. Estradiol alone doesn't predict reserve but provides important context for interpreting FSH.

What About Inhibin B? Is It Worth Testing?

Inhibin B is produced by growing ovarian follicles and declines with age. It's less commonly tested than AMH but provides additional information about follicular activity. Low inhibin B combined with low AMH and high FSH paints a clear picture of diminished reserve. However, inhibin B varies significantly throughout the cycle, making it less convenient than AMH for routine testing.

What Tests Do I Need for a Full Fertility Workup?

Ovarian reserve tests (AMH, FSH, AFC) assess egg supply, but fertility involves much more. A comprehensive workup typically includes:

  • Thyroid panel (TSH, T3, T4): Thyroid disorders can impair ovulation and implantation
  • Prolactin: Elevated levels can disrupt ovulation
  • Progesterone (day 21): Confirms ovulation is occurring
  • HSG or SIS: Assesses tubal patency and uterine cavity shape
  • Semen analysis: Male factor contributes to ~50% of infertility cases
  • Genetic screening: Carrier testing for common genetic conditions

Don't assume AMH tells the whole story. A normal AMH with blocked tubes or severe male factor infertility still requires intervention. Always complete the full workup.

How to Read Your AMH, FSH, and AFC Results Together

The AMH Analyzer is designed as the first step in understanding your fertility picture. Enter your AMH (required), then optionally add FSH, AFC, and BMI for a multi-marker assessment. The tool will generate a personalized doctor discussion guide that includes questions about additional tests you may need based on your profile. Think of it as preparation for — not a replacement for — your fertility evaluation.

Related Reading

See the full AMH levels explained pillar guide. Not sure when to test? Read When to test AMH: Best time, cost & prep. Check where your level falls on the AMH normal range guide.

Key takeaways

  • AMH is stable throughout the cycle; FSH must be tested on day 2-4 — AMH is more convenient for screening
  • AFC (ultrasound) + AMH (blood test) together provide the most accurate ovarian reserve picture
  • Low AMH + High FSH + Low AFC = strong evidence of diminished reserve
  • Ovarian reserve is only part of fertility — tubal, uterine, and male factors matter equally
  • Use the AMH Analyzer as your starting point, then complete the full workup with your doctor

Frequently asked questions

Which is more important: AMH or FSH?

Both provide valuable information. AMH is more convenient (test any day) and declines earlier, making it a better early indicator. FSH is well-established and widely used. Together they're more informative than either alone. The AMH Analyzer accepts both for a combined assessment.

Can I test AMH at home?

Several at-home AMH test kits are available (Modern Fertility, LetsGetChecked, etc.). These use a finger-prick blood sample sent to a lab. Results are generally reliable but may differ slightly from venous blood draws. Enter your result in the AMH Analyzer regardless of how it was collected.

How often should I retest AMH?

For most women, retesting every 6-12 months is sufficient unless you're actively in treatment. If you have low AMH and are considering egg freezing or IVF, your doctor may want more frequent monitoring. The AMH Analyzer accepts previous values for trend analysis.