Ovarian reserve is a term used to describe the biological principle that egg supply is finite and that egg quantity and quality decrease as a woman ages. Although it is impossible to count exactly “how many eggs are left” in the ovary and “what is their quality”, numerous surrogate markers have been proposed to characterize ovarian reserve. In general, ovarian reserve markers consist of either a blood test (like AMH) or an ultrasound.
As results of ovarian reserve tests provide us with a numerical value, it is easy to get trapped into over-interpreting the results. It must be emphasized that these tests are merely snapshots of information that do not provide a litmus test on whether or not pregnancy will occur or whether it is reasonable or not to proceed with treatment. In other words, it is important to know what these test do and do not tell you.
Anti-mullerian hormone (AMH) is a hormone produced by eggs in their early developmental stages in the ovary and is the ovarian reserve marker ”du jour”. Its level in the blood generally corresponds with the egg supply remaining in the ovary. Most fertility experts currently accept that AMH is helpful for the following:
1. As a general marker of reproductive potential.
2. To roughly predict how many eggs might be expected to result from an IVF cycle.
3. To help plan how much ovarian stimulation medication should be used in IVF.
4. To counsel patients on the risk of cycle cancellation during an IVF cycle attempt.
Noticeably absent from this list is the ability to predict pregnancy. Let’s state this again: AMH levels do not predict pregnancy.
With this knowledge, it might be helpful to refer back to one of the most reliable markers of predicting pregnancy which is simply a woman’s chronological age. We know that as age increases, the likelihood of pregnancy decreases. Many women will have their last child by the
age of 42 and after the age of 43, a live-birth becomes an extremely rare event. Indeed, the oldest reported pregnancy from IVF using one’s own eggs stands at 46.
So for young women with markers suggesting diminished ovarian reserve
(DOR) this is good news. Indeed, a recent study retrospectively analyzed AMH levels in approximately 2700 patients and observed that even if AMH levels were undetectable, pregnancy rates from IVF were still very reasonable. Indeed, for women less than 35 with an undetectable AMH, pregnancy rates were an incredible 40%!
So it’s back to the drawing board for ovarian reserve markers like AMH and their ability to predict conception. Top three prognostic factors for achieving pregnancy? Age, age and age.