Ovarian Reserve: What AMH and AFC Actually Tell You About Fertility
What ovarian reserve means, how it's tested, and what low AMH does and doesn't predict about your ability to get pregnant.
AMH is the most Googled fertility number — and the most misunderstood. Ovarian reserve measures the size of your egg pool, not the quality of your eggs. Understanding what that distinction means changes how you interpret your results.
What is ovarian reserve and why does it matter for fertility?
Ovarian reserve refers to the remaining pool of eggs in your ovaries. It declines with age and cannot be increased. Testing measures the size of this pool — not the quality of the eggs. Reserve matters for fertility treatment planning, particularly IVF, because it predicts how many eggs are likely to be retrieved in a stimulated cycle.
How is ovarian reserve tested?
The three key markers: AMH (anti-Müllerian hormone, a blood test that can be done on any day of the cycle), antral follicle count (AFC, a transvaginal ultrasound done on cycle days 2–4), and day-3 FSH. AMH and AFC together give the most complete picture of reserve. Direct-to-consumer hormone tests can give you an AMH number, but without a provider to interpret it in context, that number often creates more anxiety than clarity.
What do AMH levels mean for your fertility?
Low AMH is a strong predictor of how you'll respond to ovarian stimulation in IVF. It is a weak predictor of natural conception — those are different things, and they get conflated constantly. A low AMH in someone trying to conceive naturally does not mean they can't get pregnant; it means their egg pool is smaller, which is most relevant for how many eggs can be retrieved in treatment.
What is an antral follicle count (AFC)?
An antral follicle count is a transvaginal ultrasound performed in the early part of the cycle to count the small resting follicles visible in both ovaries. It gives a visual, cycle-specific snapshot of reserve that complements the AMH blood test. Together, AMH and AFC are the two best predictors of ovarian response to stimulation.
Does low ovarian reserve mean you can't get pregnant?
No. Diminished ovarian reserve (DOR) does not mean infertility. It means the window may be shorter and treatment decisions may be more time-sensitive. Many people with DOR conceive naturally or with treatment. Age-specific norms matter for AMH interpretation — a low AMH at 24 is more concerning than the same number at 40, and no single cutoff defines DOR across all ages.
What does low ovarian reserve mean for your options?
With low reserve, the key decisions are whether to try naturally, pursue IUI, or go directly to IVF — and how urgently. An REI with experience in managing DOR is essential for this decision. If reserve is significantly diminished, the time-value of each cycle increases, and donor egg IVF may become a conversation worth having sooner rather than later.