Measurement of ovarian reserve is an important part of any infertility evaluation. In addition to identifying those women that may have a very poor chance for success, measurement of ovarian reserve is useful for determining the correct dose of fertility drugs to use in treatments such as in-vitro fertilization - IVF.

Previously, a number of different hormone blood levels and ultrasound measurements have been used for ovarian reserve testing. These include age, day 3 FSH, inhibin B, antral follicle count, ovarian volume assessment and the clomid challenge test.

Recently, a new hormone marker, anti Mullerian hormone (AMH), has been evaluated as a marker of ovarian reserve. AMH is produced in the granulosa cells of small ovarian follicles.

Serum AMH levels from women are lower than those in men throughout life. One potential advantage of using an AMH testas a marker of ovarian reserve is that it does not seem to change over the course of the menstrual cycle. FSH, on the other hand, must be measured on Day 2 or Day 3 of the menstrual cycle or on Day 10 if it is drawn as part of a clomid challenge test.

Several factors lead scientists to believe that AMH might be a good marker for ovarian reserve. For example, AMH, like ovarian reserve, decreases with age. Some studies in IVF patients have shown lower AMH levels in women who responded poorly to fertility drugs.

Recently, doctors studied 48 women who were attempting to achieve pregnancy with IVF for the first time. The women varied in age from 25 to 43.

The women were divided into four groups based on their response to IVF fertility drugs:

• Poor - Less than 4 eggs were retrieved or the IVF was cancelled for poor response
• Normal - 4 to 8 eggs were retrieved
• Good - 9 to 16 eggs were retrieved
• High - More than 16 eggs were retrieved or the IVF was cancelled for a high response.

The women were also divided into four groups based on their AMH levels.

Those women with the lowest AMH levels tended to be older and to require higher doses of fertility drugs. All of the women who had their IVF cycle cancelled for poor response were in this group.

A correlation was found between the number of eggs retrieved and the AMH level. Those women with low AMH levels tended to get fewer eggs during IVF than women with high AMH levels. Pregnancy rates were also lower in those women with low AMH levels.

The results of this study were in agreement with other AMH studies over the past few years. However, this is the first time that the benefit of determining the AMH level at a random time during the menstrual cycle has been demonstrated. This has very significant benefit from a practical point of view.

FSH levels, for example, vary with the day of the menstrual cycle and are affected by other hormone levels. A patient with an elevated estrogen level, for instance, may have an inaccurately low FSH level. This may lead to the false assumption of normal ovarian reserve.

Oral contraceptives would also not affect the levels of AMH as they do when looking at FSH levels.

The major problem with determination of AMH levels is cost. Only a few laboratories currently offer the AMH test and the cost is significantly higher than an FSH level.