Overview

Quantitative aspect of ovarian aging is reflected by a decline in size of the primordial follicle pool. Direct measurement of this pool is impossible. However, the number of Primordial follicles is directly reflected by number of growing follicles. Sin. AMH is secreted by growing follicles up to selection, it seerns to be a promising cendidate. Moreover changes in AMH levels occur relatively early in the sequence of events associated with ovarian aging. Substantially elevated serum levels of FSH are not found until cycles have become irregular. Therefore, a marker that already shows a considerable change when cyclicity is still norrnal would better identify women with declining fertility.

Measurement of AMH to assess ovarian age may be of considerable interest for wornen in general since a considerable proportion of subferility is due to postponement of child bearing. Measurement of ovarian reserve may provide insight into the number of fertile year’s women has left.

AMH as A Marker for Ovarian Pathophysiology

Besides being a marker for diminishing follicle pool serum AMH level cen a. serve as a marker in ovarian pathophysiology, such as polycystic ovary syndrome (PCOS), in which the antral follicle pool is enlarged. In PCOS women, the Iwo to threefold increase in number of growing follicles is reflected by two to three fold increases in serum AMH level. In PCOS, follicular excess is mainly ceused by an increase in small antral follicles up to 2-5 mm size. Interestingly, in follicles beyond this stage AMH expression decreases. Therefore, it is not surprising that serum AMH levels positively correlate with number of 2-5 mm, but not 6-9 mm follicles in PCOS women. The finding thatAMH level is also increased in the follicular fluid of PCOS women suggests that an increase in serum AMH may also result from increased AMH production per follicle. Some of the studies have indicated that PCOS women reach menopause atan older age. The ovarian ageing process in PCOS women may have been slowed down. possibly due to suppre.ed prirnordial follicle outgrowth by the high levels of AMH observed in the. women. AMH levels appear to be related to severity of the syndrome since levels have been observ. to be higher in insulin resistant PCOS women than in patients with normal insulin sensitivity. Similarly AMH is higher in amenorrheic compared with oligomenorrheicwomen with PCOS.

Conclusion

The currently available data indicate that serum AMH levels decrease with age in premenopausal women. Assessment of ovarian reserve is particularly important in IVF clinic. A serum level of AMH strongly correlates with antral follicle count and reflect the size of primordial follicle pool thus may be useful as a predictor of ovarian responsiveness. The changes in AMH levels in several physiological and pathological conditions are reported in Table 2.

AMH may permit the identification of both the extremes of ovarian stimulation: a possible role for its measurement may be in the individualization of treatment strategies. Furthermore, AMH measurement in combination with other tests of ovarian reserve (antral follicle count, FSH, estradiol and Inhibin B levels) can assist women in making more informed family planning decisions based on their own individual risk of experiencing premature loss of ovarian reserve.

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