What is the AMH test?

Posted on 27 November 2018

Interviewer: Welcome back to “Knocked Up” the podcast. Now, we are recording today from outside on the first beautiful day of spring. So you may hear the occasional dog barks. And certainly you will hear some very loud birds. But we couldn’t miss the day. So today we’re back and we’re going to be talking about the AMH test.

So this is something that if you’ve being looking at freezing your eggs or having IVF, is a test you would have heard of. And today we’re going to hear Dr Raelia Lew tell us what it actually means.

Hi Dr Raelia Lew! Welcome back.

Dr Raelia Lew: Hi thank you, Welcome to season two!

Interviewer: Yes, we are back with a few more topics. Who would have thought there was so much more to talk about! So, AMH. Let’s hear about it a little bit.

So we thought there is so much more to talk about!  AMH, it’s a number. It can mean a lot. But it can also not mean as much. I guess it changes with age. I don’t know what else. Starting with AMH it’s called Anti-Mullerian hormone and it’s a blood test.

Dr Raelia Lew: Anti-Mullerian Hormone is a measure of the ovarian reserve. And what that means is it’s a way of understanding what the ovary is capable of. And in terms of certainly IVF treatment and egg freezing, where we stimulate the ovary to try and induce the development of multiple eggs in the same month, the AMH can indicate how many eggs might be available for a given person.

Interviewer: So, what kind of numbers are we seeing? Oh I suppose I should say first mullerian is not malaria, it’s with a U. That took me a while to work out!

Dr Raelia Lew: So it’s eponymous. What that means is a lot of things in medicine are named after people who discovered them. And Muller was a German guy who discovered the mullerian ducts. And the mullerian ducts actually are structures that occur in both male and female early fetuses. Kind of before we’ve decided (based the expression of our genes) whether we’re going to go down a male or a female development pathway.

And they end up being turned into the fallopian tubes and the uterus in a woman. Male fetuses at that early stage express anti-mullerian hormone in a completely different capacity. To repress the development of the uterus, and the fallopian tubes. We all start off with all the bits to make either a male or a female and depending on the instructions –

Interviewer: This is why boys have nipples…

Dr Raelia Lew: That`s true. And depending on the instructions from our genes we decide to go down either a male or female pathway.

Interviewer: So, why would someone be getting the AMH test?

Dr Raelia Lew: So we use it in fertility for a completely different reason. The gene for AMH turns on in the ovary. And in the ovary it works actually at the very early stages of regulating how our follicles leave the resting pool and go on and develop. So you’ve probably heard before, (certainly we’ve talked about it before in this podcast) that we make all the eggs we’re going to make before we’re born.

And they sit around resting and gradually they’re released. And it’s about a three hundred days journey from when the egg leaves the resting pool. Actually a whole group of eggs leave at the same time every day. But it takes about 300 days, almost a year, for an egg to go from being asleep and completely resting to being involved in a cycle.

Interviewer: Okay

Dr Raelia Lew: And anti-mullerian hormone actually has no real role directly in an IVF cycle or in an egg freezing cycle. But it’s a hormone that regulates how many eggs leave the ovarian reserve. It kind of, actually, suppresses eggs from leaving the ovarian reserve. It keeps the resting pool asleep so to speak. It’s like you think about a little nanny kind of tucking the little eggies into bed.

Interviewer: Okay

Dr Raelia Lew: And so what it does do though, is give us an estimation of the resting pool for a given person. And it doesn’t change much month to month or week to week. But gradually, over many years, it does reduce as our ovarian reserve reduces. Also, an analogy that I’ve used before and I do use clinically is that there’s a huge range of what’s normal in the AMH, absolutely huge.

Interviewer: Yes

Dr Raelia Lew: And just like someone can be an A-cup in bra size or a double D and still both are completely normal, so can a woman of the exact same age have an ovary that has a very different amount of eggs and also size of the ovary and follicle density to someone else. Just like all other biological characteristics can vary person to person.

Interviewer: It`s a good analogy because when you do look at those charts, certainly when you are in your thirties, its quite a big range around what is totally normal. And yes, so it’s all normal in the same way. Any bra size is totally normal.

Dr Raelia Lew: Yes, and I actually do see a lot of patients who come from having an AMH done by their GP and it comes back as low. And you can freak out really and worry about the fact that it might reflect immediate fertility. And actually, it doesn’t. So, women with a smaller ovary with lower follicle density might be perfectly fertile. They might be more than perfectly fertile. And so it is quite possible and happens all the time that women who are trying to conceive with a low AMH might get pregnant easily and naturally.

Where it does come into play is if a woman is  having a lot of trouble. For a huge variety of reasons, couples and women can have trouble getting pregnant.

Interviewer: It’s one of the early tests?

Dr Raelia Lew: It’s one of the early tests and it does impact how woman might experience IVF as a process. Because the more eggs you can make in one occasion and one round of treatment, the more likely you are to have a baby from that round of treatment. And where women are disadvantaged where they have a low AMH, is that they may be able to make only a low number of eggs with stimulation. Because, I always say, no matter what dose you have of medication, you can’t stimulate a follicle if it’s not there.

You can only stimulate what the ovary has to work with and as I said it takes 300 days for follicles to leave the resting pool and get to the point where they’re going to get involved in a cycle. There will be some cycle to cycle variation in the same person even with the exact same regimen of medications. There will also be some women who respond better to one combination of medications than another. And that also can be something very individual.

But at the end of the day we can only work with what the ovary is capable of giving us. Women who do have a low AMH may take more rounds of treatment to get pregnant than women who have a really kind of “kick-ass” ovarian reserve.

Interviewer: Okay, and so if you were curious about knowing what your level was (ecause maybe you want to freeze your eggs, or you may have a bit of trouble conceiving),what steps do you go through to get the AMH? Do you speak to a fertility specialist first? Or can you just go to your GP? This is in Australia.

Dr Raelia Lew: I have some patients who go to a GP and do a whole gamut of tests before I see them and others who come with nothing and we start from scratch. Both approaches are totally fine. There are advantages and disadvantages to both approaches. There are a lot of GPs who are quite confused about AMH because it’s a test that is useful only in the context of considering fertility treatments.

Interviewer: Okay. So really it means absolutely nothing unless you are considering having a baby.

Dr Raelia Lew: Unless you’re considering = having a baby and needing help or –

Interviewer: Right. Freezing your eggs.

Dr Raelia Lew: Considering egg freezing. Actually just very recently, hot-off-the-press, I have been involved in generating the first Australian New Zealand official guideline on egg freezing, w is yet to be published. It’s still in the process of perfecting the manuscript.

Interviewer: Yes, congratulations.

Dr Raelia Lew: Thank you. But we are trying to remove the term ‘social egg freezing’ from conversation. Because it’s my feeling –

Interviewer: It`s ridiculous.

Dr Raelia Lew: Well it is ridiculous and my feeling is that it’s a term that can marginalise, stigmatise, and it can attribute blame to women for accessing a technology that is a completely robust and worthwhile. It can really miss the big picture of why women do freeze eggs. So, we as Australians, are leading the charge to remove it from the medical nomenclature. And if anyone’s listening around the world, feel free to join the bandwagon!

Interviewer: Sounds good. We need to remove the stigma in every way we can. Okay, so back to AMH, you have gotten your test and you have got a number. Give us a range of numbers that is totally normal. When should we worry? What do we do with this number?

Dr Raelia Lew: So,it also depends on the age of the person. Most women do have a low AMH leading into their 40’s. That’s pretty much, part of our biology, that our ovarian reserve does drop off as we get older. Usually, from age 35 there’s a dramatic decline. That does also affect how many eggs might be available in a treatment for women at that age. A second important factor is that egg quality also does decline.

And so, the younger you are when you have either IVF treatment or freeze eggs the better prognosis per egg. AMH can range wildly, so some people come with an AMH of less than one. That would be a very low AMH at any age. Some people have an AMH that’s you know, kind of between 5 and 25 and I call that pretty normal. But it can range wildly and be normal. And some women who do have polycystic ovaries or just multi-follicular ovaries or just born with you know God’s blessing of lots and lots of eggs, can have an AMH over 30.

I just checked off a result today for one of my patients with polycystic ovaries who had an AMH of over 100. So you know it can range quite wildly. Another important thing to say is that AMH should not be measured on the pill. And it should not be measured in women who do not ovulate because they have central suppression or hypothalamic anovulation. That’s a big word but it basically occurs sometimes when women are super skinny. Either if they’re athletes or they are really sick or they’re anorexic. They just don’t ovulate.

The AMH can be suppressed in those women as well. So those are the two groups that we should not be measuring AMH. Women who have had recent chemo and might be measuring AMH to see how their ovary has rallied….

Interviewer: Survived the chemo?

Dr Raelia Lew: They should wait a few months before they do it. Immediately after the chemo is not the time to do the AMH. You’ve got to wait three four months to measure.

Interviewer: I suppose thinking about the age group that would be getting the test,there is a likelihood that they’re using some sort of contraceptive. Either the pill or an IUD.

Dr Raelia Lew: Yeah IUD`s are okay.

Interviewer: So you can have an AMH whilst you have an IUD inserted and it won`t affect the readings?

Dr Raelia Lew: It won’t affect it but in terms of the pill we should have a one-month holiday,  a natural period and check the AMH in that context.

Interviewer: Okay, so you go and have the blood test and then you get your number back. And what do you do? You then decide about freezing or?

Dr Raelia Lew: I think AMH is one test that we do to counsel women on how well they might do in an egg freezing cycle or IVF cycle. And to discuss, I guess, “a priori”, how many treatments might be needed. A ballpark to get kind of a reasonable number of eggs in the bank. I usually encourage women to freeze twenty to thirty eggs if they’re, you know, around thirty-five. Because we know from studies that have looked at really young fertile egg donors, that each egg gives you about a 6.5 percent chance of having a live-born baby. And that you need to thaw on average about fifteeneggs to have a live birth.

Interviewer: Okay.

Dr Raelia Lew: And you can hear our mascots. Hear the podcast mascots Daisy and Bella in the background.

Interviewer: If you are at the stage of having an AMH test (because of what you’re thinking of going forward and doing, whether it is egg freezing or the full IVF process, you should engage a specialist from the very beginning before you have the tests.

Dr Raelia Lew: Look, I’m quite happy for GPs to arrange an AMH test. But I think if a patient’s requesting an ovarian reserve assessment they really deserve to see a fertility specialist. Because it’s impossible to interpret that test in isolation. You can actually do harm to a patient by either telling them everything’s okay, or engendering fear or anxiety because of a low number, or false reassurance because of  a high number.

Interviewer: Which is in isolation…?

Dr Raelia Lew: This is one factor that is in isolation. Not necessarily going to give a full picture. There are women that I treat who have a high AMH who come to me with infertility. We do embryo testing, which I often do in IVF for couples struggling to conceive at an older age.Over 37 it’s extremely cost-effective because a lot of completely beautiful normal-looking embryos have made catastrophic genetic mistakes and can’t possibly be a normal baby. I had a patient the other day that was 39 years old and she had a great AMH. We were super excited that she made 6embryos from her first IVF cycle.

Interviewer: Wonderful

Dr Raelia Lew: She had an embryo transfer of her first embryo fresh which didn’t take. Then we were lucky to get the results of the other 5. It showed that 4out of 5 were completely abnormal, and only one was normal. So, the take-home message is quality is, you know more important than quantity. But quantity does impact how quickly you can find the ‘golden egg’ that’s going to make the golden embryo in the context of IVF treatment.

These are complex nuanced issues.The whole of your fertility history and that of your partner (your medical history or lifestyle factors), they all need to be considered to optimise the chance of creating a baby. It’s not a one second answer in terms of what’s your AMH level. My advice is that if you’re thinking about fertility deeply enough to be asking for an AMH test, you deserve to have a full comprehensive assessment through a fertility specialist.

Interviewer: Let’s just be aware of the nuance, as opposed to someone who’s day job isn`t dealing with these numbers.

Dr Raelia Lew: Yeah and just to be fully informed

Interviewer: About what the results means…

Dr Raelia Lew: You can’t actually make decisions that are in your best interest if you don’t have all the information and the full picture. Tthe AMH is only one piece of a much bigger puzzle.

Interviewer: I think with AMH it’s something people have heard of and that`s why there’s a bit of a thing about ‘what is your AMH number’. Actually you’resaying it’s one tiny piece of the puzzle.

Dr Raelia Lew: Yes, and it’s an easy thing to measure. It’s something that you can easily and quickly measure and give an answer. However, the interpretation of that answer can lead to a fully informed situation where you have a very realistic assessment. That’s if you see a fertility specialist and have it explained in the context of your situation, or it can lead to either false reassurance or unwarranted fear.

Where patients delay seeking help, they sometimes come back when it’s much harder to help them. When they should have really been referred for treatment….

Interviewer: At the very beginning…

Dr Raelia Lew: Or in some cases it may when an AMH returns as low, but there are no other real issues. It may generate a whole heap of anxiety that’s completely unwarranted. So, you know, it’s really one of these things that as I said, if you’re contemplating having the test you should really have a full specialist opinion.

Interviewer: Speak to a specialist before getting the test. Okay, thank you. For more information about Dr Raelia Lew Lew and her practice visit or on all the socials at Women’s Health Melbourne.


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