What is an Anti-Mullerian Hormone (AMH) and should it be tested often?

Anti-Mullerian Hormone (AMH) is a reflection of the ovarian reserve. The lower the AMH, the lower the reserve. A low AMH likely reflects as earlier menopause as well.

A common belief is that a low AMH lowers pregnancy success. Recent evidence shows that this may not be true, especially in women over 40 years old. Women with a low AMH (<1) rarely respond well to traditional, high stimulation IVF treatments. A low AMH may narrow fertility options and change treatment management.

From a fertility perspective, I look at AMH as a guide.

A low AMH shows that the patient needs to be aware of her fertility concerns. If a woman in not interested in having a child at the moment, then she needs to be followed more closely to keep all her fertility options open. She may want to consider egg freezing or embryo banking before her reserve worsens, otherwise, she may have difficulty finding physicians who can help her. If she is interested in conceiving sooner than later, she may want to consider IVF sooner if she would like to have more than one child. This would optimize the chance of having a second or third child should the ovarian reserve worsen.

How frequently should AMH be tested?

If AMH is normal, no more than once per year. Ovarian reserve will not plummet unless there is a traumatic injury or illness. Makes sense to test AMH after pelvic surgery (e.g., fibroid removal, ovarian cyst removal) or a diagnosis of auto-immune illness (very common to see a woman with DOR and history of autoimmune thyroid disease).

Repeating more than once per year without this history increases the risk of false-positive and the emotional stress associated with it.

If AMH is low, makes sense to repeat result in 1-3 months to rule out lab error.

If AMH is confirmed low, and a woman is open to pregnancy, then she should seek care from a health care provider ASAP.

If AMH is confirmed low, and the patient is not interested in pregnancy, it makes sense to repeat AMH in another 6 months to make sure that reserve is not quickly getting worse (at which point, the patient should consider egg preservation). If AMH is stable, then yearly AMH.