Anti-mullerian hormone - or AMH - is often tested as part of a fertility work-up to assess ovarian aging or ovarian reserve; higher AMH values are thought to reflect a greater, more youthful pool of ovarian follicles whereas lower numbers - below 1.0 ng/ml - are considered to be on the low side and may portend reduced fertility.

AMH is produced from the antral follicles on the ovary and levels peak at around 24 years of age; AMH levels tend to decline as a woman transitions through peri-menopause and may be virtually undetectable after menopause. However, this natural decline in AMH values is often delayed in women with PCOS.

AMH is produced from the granulosa cells of the tiny antral follicles and pre-antral follicles follicles on the surface of the ovaries, and so, the more follicles you have the highr your AMH levels are likely to be.

Antral follicles are visible via ultrasound upon the ovarian surfaces and are also used as a marker for ovarian reserve: a greater number of antral follicles is thought to reflect more robust fertility. AMH values are known to reflect the size of the pool of tiny ovarian antral follicles which define a woman's 'ovarian reserve'.

Normal AMH values are regarded as being between 1.0 and 3.5 ng/ml; when AMH values dip below 1.0 it is widely thought that ovarian reserve - and fertility - may be in decline.

This said, many women can and do conceive both naturally and with ART/IVF with lower AMH values but it may take more time to conceive and more care may need to be taken when selecting the kind of IVF protocol to undergo. A higher level of self care with diet, nutritional supplements and lifestyle choices may be especially healpful and restorative when AMH values are becoming low.

AMH is though to be a particularly accurate marker for IVF success but it's predictive utility for gauging the likelihood of natural conception is a little less clear.

AMH is more than just a marker of ovarian reserve, sometimes AMH levels are unusually high and this finding has been linked with polycystic ovarian syndrome or PCOS. Women with PCOS tend to have a greater number of antral and pre-antral follicles which pump out extra AMH leading to higher serum values which may rise well into double digits. But a higher AMH level in women with PCOS does not necessarily mean better fertility.

In fact, the greater the AMH value, the more severe the signs and symptoms of PCOS are likely to be. Higher, out-of-range AMH values may play a role in anovulatory and irregular cycles which are typical of PCOS; AMH has a functional role within the ovary and excessive amounts of AMH are thought to have a suppressive effect upon the process of ovulation:

"AMH has an inhibitory role in the ovary, reducing both primordial follicle initiation and follicle sensitivity to FSH by inhibition of aromatase. It is for this reason that AMH is a focus of interest in polycystic ovary syndrome (PCOS)." (1)

"To conclude, AMH appears to have a major inhibitory role during folliculogenesis, which may contribute to anovulation in PCOS."(2)

It seems that you can have too much of a good thing!

Too little AMH may reflect declining ovarian reserve and reduced fertility whereas too much AMH may reflect ovarian dysfunction typical of - but not limited to - PCOS which can also compromise the chances of conceiving.

Many researchers are calling for AMH to be recognized as a diagnostic marker for PCOS which can be quite difficult to diagnose in relatively asymptomatic women.

By using high AMH values as a diagnostic test for polycystic ovarian syndrome, may women who have been diagnosed with unexplained anovulation or unexplained infertility may find themselves re-tagged with a different label: PCOS. Here is a peak at some recent conclusions regarding AMH and PCOS:
"
"AMH has been shown to be a good surrogate marker for polycystic ovary syndrome (PCOS)."(3)

"In conclusion, the assay of the serum AMH may represent an important breakthrough in the diagnosis and in the understanding of PCOS." (4)

'In clinical practice it is common to encounter patients who turn to medicine in search of a cure for female infertility. In our experience, AMH two or three times the normal amount (10 ± 2.28 ng/mL), is a good indication of PCOS and infertility." (5)

Suffice to say, a higher-than-normal AMH value may indicate that you might want to ask your physician about the possibility of PCOS. If you have AMH values below 1.0 you may want to apprize yourself of the many self-care strategies which may help you to conceive successfully with a lower AMH value.

Please note: This article is for purely informational purposes and is not intended to diagnose or to replace medical or dietetic advice for which you should consult a physician or dietitian.

I regularly post extra updates on new fertility research, tips and strategies, along with research on environmental toxins and fertility on my Facebook page

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(1) Reproduction. 2010 May;139(5):825-33. doi: 10.1530/REP-09-0415. Epub 2010 Mar 5.
Anti-Müllerian hormone and polycystic ovary syndrome: a mountain too high?
Pellatt L, Rice S, Mason HD.

(2) Reproduction. 2010 May;139(5):825-33. doi: 10.1530/REP-09-0415. Epub 2010 Mar 5.
Anti-Müllerian hormone and polycystic ovary syndrome: a mountain too high?
Pellatt L, Rice S, Mason HD.

(3) Clin Endocrinol (Oxf). 2006 Jun;64(6):603-10.
Anti-Müllerian hormone (AMH) in female reproduction: is measurement of circulating AMH a useful tool?
La Marca A, Volpe A.

(4) J Clin Endocrinol Metab. 2003 Dec;88(12):5957-62.
Elevated serum level of anti-mullerian hormone in patients with polycystic ovary syndrome: relationship to the ovarian follicle excess and to the follicular arrest.
Pigny P, Merlen E, Robert Y, Cortet-Rudelli C, Decanter C, Jonard S, Dewailly D.

5) Int J. Gen Med. 2011;4:759-63. doi: 10.2147/IJGM.S25639. Epub 2011 Nov 2.
Serum anti-Müllerian hormone as a predictive marker of polycystic ovarian syndrome.
Parco S, Novelli C, Vascotto F, Princi T.