Anti-Müllerian Hormone (AMH)

By RRM Academy Reviewed by Dr. Naomi Whittaker, MD, Board-Certified OBGYN, MIGS, NFPMC, FCI Updated May 7, 2026

AMH measures the number of small antral follicles currently active in the ovaries. It reflects current activity, not a fixed inventory. That distinction matters: AMH is a snapshot of this cycle's follicular activity, not a permanent verdict on reproductive potential.

What AMH does not measure is equally important. It does not measure egg quality, follicle quality, or how well ovulation is functioning. A woman with a low AMH result may still produce a competent follicle this cycle. For natural conception, one good egg per cycle is all that is required.

AMH's significance as a "low" number is largely anchored to protocols that require retrieving six to fifteen eggs at once. That is the IVF context. An RRM clinician asks a different question: what is this cycle's follicle doing? A single well-developed, well-supported follicle is the clinical target. The total pool size is a starting point for the workup, not the answer.

A low AMH result is a diagnostic signal, not a sentence. The question is why. Age is one factor. But autoimmune conditions, prior ovarian surgery, endometriosis, vitamin D deficiency, and thyroid dysfunction can all reduce AMH before age alone explains it. AMH can also change. A meta-analysis of 8 studies found DHEA supplementation significantly raised serum AMH in women with diminished ovarian reserve (Yin et al., BMC Endocrine Disorders, 2022).⁷⁷ Vitamin D repletion shows a similar effect. Treating correctable contributors is the first step, not a last resort.

AMH also has a ceiling problem. In PCOS, AMH is often markedly elevated because many small follicles accumulate without maturing. A high AMH number is not simply reassuring. It reflects a pattern of arrested follicle development that warrants investigation.

Unlike FSH, AMH does not fluctuate significantly across the menstrual cycle. It can be drawn on any cycle day, which makes it useful for tracking trends over time. But a single result should not anchor a clinical course. In RRM practice, AMH is interpreted alongside AFC, cycle chart patterns, timed hormonal panels, and a follicle maturation study when indicated. A low AMH with normal AFC and regular ovulatory cycles tells a different story than a low AMH with anovulatory cycles and a shortened luteal phase. The number alone is not the diagnosis. It is the beginning of the workup.

This content is for educational purposes only and does not constitute medical advice. Consult an RRM clinician or healthcare provider for guidance specific to your situation.