AMH and Ovarian Reserve
Are you thinking about getting your ‘fertility’ tested? Do you want to know how many eggs you have left and want to get your AMH tested?
To start I want to explain that a single fertility test does not exist, fertility is multi faceted and there are a range of tests you can do. For now let’s just speak about AMH or ovarian reserve.
So what is ovarian reserve? When you are a female foetus inside your mum, you have the most eggs you’re ever going to have. At about 20 weeks gestation you have about 6-7 million eggs. Then by the time you are born you have already lost about half of those, and you continually lose eggs all the time. Imagine you have a vault of eggs in your ovaries, and the number in your vault is continuously decreasing since the moment you have an ovary.
Most people assume that a reduction in their egg count is one per month, due to ovulation. But the truth is a number of eggs are released from the vault monthly in that ovulation cycle. But, only one is chosen by the body to be matured and this is the egg that you ovulate with. The rest of the eggs that were released, die. So the commencement of ovulation is just your body saying now you are ready to get pregnant, the loss of eggs is happening regardless of if you are ovulating or not.
So how do you test ovarian reserve? It’s via blood test looking at your levels of anti mullerian hormone, AMH which tells us how many eggs are being released from that vault each month.The more in there, the more you release, and the less in there, the less you release. So an AMH result translates to give us a rough idea of how many eggs are left in that vault.
If you are thinking about getting your AMH tested, I want to make something VERY clear, that your AMH count is INDEPENDENT of your fecundability, that is your ability to naturally fall pregnant that month. So for example if you have two people, they are both 30 years old and one has low ovarian reserve and have 5 eggs coming out of the vault that month, and the other person has a normal ovarian reserve so they have say 20 coming out of the vault. NO matter how many eggs they have left in that vault, both people will be ovulating one egg per month (and the rest of the eggs released will die), and so their ability to fall pregnant with that one egg, that month, is the same for both.
So if you have a low AMH reading and you are trying to fall pregnant naturally, that does NOT decrease your chances of falling pregnant, nor does having a high AMH guarantee that you will fall pregnant easily.
It was actually IVF clinics that started testing AMH to understand how much medication to give you during the stimulation phase of IVF. So, AMH should NOT be looked at as a stand alone test, it needs context!
Are AMH levels stable or what can affect the result? Your AMH is likely to be higher in the follicular phase of the cycle, the first two weeks, and the best time to test it would be in this preovulatory phase. Although, most testing companies include it in a test of all the sex hormones which is done on day 2-5 of your period.
Whilst you are on the oral contraceptive pill your AMH level is about 20% lower, - so you SHOULD NOT get tested soon after coming off the pill as this may indicate that you have lower levels of AMH than the reality. For the average person, it takes around 3 months for those numbers to normalise after stopping the pill, remember that is the average, so it may take you even longer.
Similarly, during pregnancy your AMH is significantly reduced, so you should be waiting at least 5 months postpartum before testing and even then you should look at the results with caution.
Binge drinking (present or past) and vitamin D deficiency have been linked to lower AMH levels. So please make sure if you are testing your AMH levels that you get your vitamin D tested alongside it so you know if you are deficient, to regard your AMH result with that context in mind.
There is a lot of controversy around AMH testing so please make sure you fully understand what is really means before getting yours checked. A low AMH result can cause a lot of people to panic and believe that they will struggle to conceive and that their fertility is ‘running out’. Nowadays a lot of companies are offering AMH testing with at home finger prick tests and a lot of gynaecologists will run an AMH test without letting you know if you ask for a fertility MOT. Some believe that if you are young and thinking about getting your eggs frozen, if you know you do not want to have children anytime soon, that testing AMH will be beneficial as it may impact how you make this choice. Others believe that this test will cause undue stress as it tells you little about the quality of the eggs being released monthly and that it doesn’t decrease your ability to fall pregnant naturally. Please, whatever you do, just understand what the result would mean either way and think before testing.