When I was around 35 and single, I started to feel the tick of the biological clock and came pretty close to paying a lot of money to freeze my eggs. In the end I was dissuaded by the specialist due to the technology not being advanced enough to guarantee survival of my eggs when thawing (a lot has actually changed with freezing techniques since then). During the next few years I continued to stress about whether or not I would meet someone in time to have children and even looked up potential sperm donors on the internet. Luckily, it all worked out in the end – I met someone and recently had a baby with him. We ended up needing to do in-vitro fertilization (IVF) due to my fallopian tubes not working appropriately and during the testing for IVF, my ovarian reserve, that is the quality and quantity of my eggs, was tested. When my lab results came back I was pleasantly surprised – my ovarian reserve was actually really good! If only I had had it tested back when I was in my mid-thirties, it would have given me peace of mind and I wouldn’t have felt so anxious about my child-bearing future. As well as potentially reducing anxiety, ovarian reserve testing can also give you a heads up that you might need to get a move on with your baby-making plans or that you should consider freezing your eggs for the future if the results are lower than expected. However, you should be aware that if you get good test results back, this is still no guarantee of a baby in the future, just as not-so-great results don’t necessarily mean that all is lost and you will never have a child. All ovarian reserve testing can do is give you a snapshot of your ovaries at a certain point in time, giving you information upon which to act.
How is ovarian reserve tested?
There are three main ways to test for ovarian reserve: measuring the levels of anti-Mullerian hormone (AMH) and follicle-stimulating hormone (FSH)/estradiol as well as an ultrasound-based test called the basal antral follicle count.
The AMH test
The AMH test is a relatively recently developed blood test that can directly measure the amount of eggs left in your ovaries as well as, to a lesser degree, the quality of these eggs. AMH is first produced by early microscopic follicles (fluid filled sacs that each contain an immature egg) which have just left the primordial stage and these follicles will continue to produce it until they attain a diameter of 8mm or more, after which production stops. With increasing age, the size of the pool of early follicles decreases and consequently so does the level of AMH. AMH levels do not vary much during the menstrual cycle and can therefore be measured on any day of the cycle.
The FSH and estradiol test
Another hormone used for assessing ovarian reserve is FSH. This hormone is produced by the pituitary gland at the base of the brain and stimulates the ovaries to produce a good follicle. As a woman ages, it gets harder and harder to stimulate the ovaries to develop a good follicle and as a result the level of FSH rises in order to counteract this resistance. The FSH test needs to be done on day 2, 3 or 4 of your cycle so your doctor can see how much FSH is needed early on in your cycle in order to kick start your ovaries to produce a follicle. However, the FSH test is not as straightforward as the AMH test. You can have an FSH level that is normal but this may be being suppressed by estradiol. If the estradiol levels are high on the same day of testing as FSH then is almost certainly what is happening.
Assessing your basal antral follicle count
This ultrasound-based test is most often used for women who are undergoing IVF and is considered to be one of the best tests for assessing ovarian reserve. Antral follicles are small follicles, measuring only 2-9 mm across, which are visible on ultrasound and the number of these is indicative of how many microscopic primordial follicles still remain in the ovary. If only a few antral follicles are visible, there are substantially fewer eggs remaining and if there are a high number, this means that your ovarian reserve is good. Here are some general guidelines as to what total (both ovaries) antral follicle count numbers mean:
- Less than four – extremely low count
- Four to eight – low count
- Nine to thirteen – somewhat reduced
- Fourteen to twenty-one – Intermediate (and normal) count
- Twenty-two to thirty-five – Good (and normal) count
- More than thirty-five – very high count, may be due to polycystic ovarian syndrome3
So, the bottom line is, if you want to have children at some point in your future, it really makes sense to assess your ovarian reserve. Testing is a good idea at any childbearing age, but is particularly important if you are in your mid- to late-thirties. Once you have an idea of how healthy your ovaries are, you can put plans in place for your future baby, whether it is making the decision with your partner to stop using contraception sooner rather than later, freezing your eggs, or looking for a suitable sperm donor and getting your head around single parenthood if you are single and definitely want a child. And in the event that it is good, it means that you don’t have to put yourself through unnecessary worry.