What is AMH?

24 April 2020

Amy

What is AMH and what do low AMH levels mean?

When women are born they already carry all of the eggs that they will ever have in their lifetime (approximately 1-2 million), these are stored within follicles in the ovaries. By the time a woman first hits puberty, the number of potential eggs left has usually halved and continues to fall each month after that – but at a slower rate. Beginning at the first menstrual cycle, a woman’s body constantly recruits a group of small ovarian follicles, each containing an immature egg. Of all of these very small follicles, there will usually be one that has the potential to respond to hormones, growing sufficiently enough to ovulate an egg.

It is most common for a woman to ovulate one egg per month from a select follicle, although several can develop in each cycle. Those follicles that do not ovulate and release a mature egg will dissolve – a process known as atresia. Roughly 99% of ovarian follicles dissolve without ever becoming mature enough to release an egg. This process repeats itself every month. The follicles that dissolve, do not regrow and the overall pool of available eggs gets smaller every month.

What is AMH?

AMH stands for Anti-Mullerian Hormone. AMH is a protein hormone that is produced by the granulosa cells in the small follicles (tiny pouches that contain eggs in the ovary). Granulosa cells are what help to develop eggs in the ovaries of a woman. AMH is given off by these cells in the highest amounts when the follicles are in the preantral and small antral stages of development (less than 4mm in size).

As follicles grow larger the amount of AMH being created starts to decrease. By the time a follicle reaches approximately 8mm in size, the amount of AMH still being produced is almost non-existent. Because there are always preantral and small antral follicles present on the ovaries, it means that AMH levels are fairly constant from day to day. Therefore AMH testing can be done on any day of a woman’s cycle.

Aside from helping to provide information about a woman’s fertility, AMH also plays an important part in the development of sexual organs in an unborn baby. Within the early weeks of pregnancy, a baby will start developing its reproductive organs, at this point, the baby will already have either XY genes to be male or XX genes to be female. If the baby has male genes, a high amount of AMH is produced which helps to promote the development of male organs and suppress the development of females. If there are uncommonly low AMH levels at this point, it is possible for both male and female sex organs to grow.

If you are considering IVF treatment to help you conceive, it can help to know your levels of AMH. This is because AMH can be used to predict the number of ovarian reserves you have, which will impact the likelihood of IVF success. We understand the worry of low AMH and IVF and are always here to support you. It requires only a simple blood test to access levels of AMH, so if you are worried then please get in touch via phone on 020 3974 0950 or email appointments@evewell.com to arrange a consultation with one of our specialist doctors who can talk you through the process.

And if you want to find out a little more about IVF please read our guide on IVF here.

How do high and low AMH levels affect fertility?

AMH levels can be an indicator of how ‘active’ your ovaries are. As you age, the natural pool of potential eggs you have in store begins to decrease and as this happens there will be fewer preantral follicles produced, which means less AMH will be released. A low AMH level reading can be indicative of a smaller pool of potential eggs.

Low AMH levels do not cause or indicate infertility but are more a sign that the reserve of potential eggs is lowering. Where there are fewer potential eggs in the ovaries, the chance of one developing, being released and becoming fertilised decreases.

During fertility treatment, your ovaries will be stimulated to try to encourage these preantral follicles to continue to grow and produce an egg. This is done so that instead of collecting 1-2 eggs per month, we can stimulate growth and potentially collect more.

What does having low AMH levels mean?

Having low AMH levels can indicate that your ovaries are producing less of the preantral follicles. This is important as the fewer the number of follicles there are means there less than can be stimulated for assisted contraception. Do not worry though, as having low levels of AMH does not necessarily indicate that you are not ovulating each month or are unable to get pregnant naturally, or by IVF. Knowing that you have high or low AMH levels gives us an idea of how effective we think stimulation and IVF might be, as we can only stimulate the preantral follicles that are already there.

Low AMH levels can be caused by a declining number of follicles in your ovaries. One of the biggest factors leading to a lower number of follicles in your ovaries, and subsequently low AMH levels, is age – as follicle reserves naturally diminish over time. Other things that can cause low AMH levels though include chemotherapy, inherited genetics, smoking or environmental factors. Still, even if you have low AMH levels does not mean you are infertile and that you are unable to conceive – either naturally or by IVF treatment.

What is an AMH test?

An AMH test is a simple blood test that can be performed during any stage of your menstrual scan. The information is supported by an ultrasound scan of the ovaries to look for those very small follicles. We recommend an AMH test to all women undergoing fertility treatment as it will aid our ability to provide you with the best fertility treatment and achieve a successful outcome.

What are normal levels of AMH and how do we interpret an AMH blood test?

Normal levels of AMH vary considerably for each unique individual and can hinge on factors such as age and personal medical history.

Laboratory parameters place a normal level of AMH between 0.2 and 39.1 pmol/L. An AMH test result is not interpreted in isolation, instead, they serve your doctor to form a larger picture. That being said, AMH levels can help doctors to estimate the number of follicles inside the ovaries, and in turn, the woman’s egg reserves. Measurement of AMH levels can also be used to predict how greatly the ovaries will respond to hormones used during an IVF cycle.

Having results from an AMH test allows us to personalise your stimulation schedule so you have the best chance of achieving optimal stimulation for successful fertility treatment.

Treating low AMH levels: how to increase AMH levels

As AMH decreases naturally with age as the ovaries begin to wind down their production of eggs, there is little that can be done to increase AMH levels. There is limited concrete evidence that suggests specific diets or supplements can maximise or boost AMH production temporarily.

How we can help you with low AMH levels

At The Evewell we deeply care about all of our patients and their loved ones. If you are considering having an AMH test or Fertility treatment, please get in touch with us to see how we can help. We can arrange a consultation with one of our specialist doctors to guide you through the process or refer you to our fertility counsellor for support. Whatever your needs, we’re here.

Get in touch by either emailing us at appointments@evewell.com or calling 020 3974 0950.

Please see the full list of Fertility services we offer here.