AMH and antral follicle count are the most useful modern markers of ovarian reserve and are often broadly concordant, but they can disagree. FSH is less sensitive and more cycle-dependent. None of these tests independently tells you egg quality or your chance of natural conception.
What ovarian reserve testing is actually for
Ovarian reserve tests estimate the size of the remaining recruitable follicle pool and, in fertility treatment, help predict how the ovaries may respond to stimulation.
They are much better at predicting oocyte yield than predicting whether a person can conceive naturally or whether a particular egg is chromosomally normal.
AMH: convenient and sensitive
AMH is produced by granulosa cells in small developing follicles and can be measured throughout much of the menstrual cycle.
ASRM notes that AMH tends to fall before basal FSH rises, which makes it a more sensitive marker of diminishing reserve than FSH.
Hormonal contraception can lower AMH and should be considered when interpreting a result.
AFC: the ultrasound count
Antral follicle count is the number of small antral follicles seen on early-cycle transvaginal ultrasound.
In experienced centers, ASRM considers AFC a reasonable alternative to AMH, and the two perform similarly for predicting ovarian response.
AFC still depends on ultrasound technique and the person doing the count.
FSH: useful, but noisier
Basal FSH is usually interpreted with estradiol early in the menstrual cycle.
High FSH can be a fairly specific sign of diminished ovarian reserve, but normal FSH can miss earlier decline. Estradiol can also suppress FSH and make the value look more reassuring than it otherwise would.
Why results can disagree
- Normal biological variation.
- Hormonal contraception affecting AMH or AFC.
- Different laboratory assays.
- Ultrasound technique and observer variation.
- Cycle timing for FSH and estradiol.
- One marker changing earlier than another.
An isolated discordant number deserves interpretation, not a panic diagnosis.
What if AMH is low but AFC looks normal?
Your clinician may repeat or contextualize the result rather than choosing whichever number is more frightening.
Age, prior ovarian surgery, endometriosis, chemotherapy history, treatment response, and the actual fertility goal all matter.
What if AMH is normal but FSH is high?
Because FSH can vary between cycles, the clinician may look at cycle timing, estradiol, repeat measurements, and AFC.
No combined model has consistently proven dramatically better than the individual markers for predicting ovarian response.
The mistake: converting reserve into a pregnancy forecast
ASRM is explicit: ovarian reserve markers are poor independent predictors of reproductive potential. Low AMH does not mean natural conception is impossible, and a reassuring AMH does not guarantee fertility.
Age remains much more strongly tied to egg quality and reproductive success.
Use reserve tests to plan response, not to declare fertility.
- Usually discussed when
- AMH, AFC, FSH, or estradiol appear discordant or a single result is driving a major treatment recommendation.
- Main upside
- Putting multiple markers into clinical context can improve stimulation planning and prevent overinterpretation of one number.
- Main tradeoff
- Repeating tests can become its own anxiety loop if the result would not change the plan.
- Which result do you trust most in my case, and why?
- Could contraception, cycle timing, or assay differences explain the mismatch?
- What treatment decision changes because of these numbers?
- Are we using reserve to predict egg yield or incorrectly using it to predict natural fertility?
Frequently asked questions
Which is better, AMH or AFC?
ASRM considers both useful and broadly comparable for predicting ovarian response when AFC is performed in an experienced center.
Can low AMH mean poor egg quality?
AMH mainly reflects quantity/reserve, not egg quality. Age is much more informative about egg-quality-related reproductive risk.
Can normal AMH guarantee fertility?
No. Ovarian reserve tests are poor independent predictors of natural conception.