Credit companies try to convince us we should know our credit score.  Since I am not buying a house or a car I’m not sure why I need to know that number. The only numbers I have memorized are my phone number, street number, my SIN number and my visa number.  I would add one number to the list of “should know” for women trying to conceive: AMH.

Antimullerian Hormone (AMH) is a number women trying to conceive should know… at least roughly. Note: AMH is sometimes written as “Mullerian Inhibiting Substance” on some reports.

AMH is a hormone released by granulosa cells in antral and pre-antral follicles. In other words, it is a hormone made by the cells that surround immature eggs.  This means if you have a lot of immature eggs, then you will have a high AMH level which is good.  If you have a low AMH, then you have a low egg count or ovarian reserve.

Other measures of egg count or ovarian reserve are FSH level on day 3 of the menstrual cycle and antral follicle count (AFC) determined by transvaginal ultrasound.  The problem with the day 3 FSH is that it is not all that accurate, fluctuates with the cycle day, can’t really be interpreted if you don’t have a regular menstrual cycle and is useless if you are taking any hormones (e.g. birth control pill).  The problem with an antral follicle count (AFC) is that it is done by a vaginal ultrasound usually by an infertility specialist, so there is a barrier to getting this information quickly.

So, AMH is the best measure of egg count/ovarian reserve.  AMH can be drawn on any day of the menstrual cycle.  It is a bit suppressed if you are taking hormones like the birth control but can still be interpreted.

AMH is reported by labs either in pmol/L or ng/mL. Be sure to check the units because a 3 in ng/mL is excellent but bad in pmol/L, for example.

In BC, AMH is unfortunately not covered by our provincial health plan, which is wrong. It should be.  It costs about $70-90 depending on the lab you attend.

AMH allows a woman to know her ovarian reserve.  It also lets us estimate the best dose for IVF medications and predict how successful IVF will be.  It gives us a sense of the time until the start of menopause as well.

In my practice, I like everyone to have an AMH level when we first meet. I also do an AFC. I don’t repeat an AMH all that often unless more than a year has passed (and not always if I have a recent AFC), if the person has had ovarian or endometriosis surgery, if the IVF outcome was surprising, the person is over 40 and considering another IVF cycle (it can drop quickly in the 40s), or if a person requests it.

You don’t need to know your exact AMH level if you are trying to conceive, honestly, but knowing if it is high, low or average is really helpful.

 Dr. Beth Taylor MD, FRCSC

Reproductive Endocrinology & Infertility