Serum anti-Müllerian hormone dynamics during controlled ovarian hyperstimulation.

Background: The study aim was to investigate possible changes in serum anti-Müllerian hormone (AMH) levels during controlled ovarian hyperstimulation (COH), and their possible relationship with follicular development and other ovarian hormones.

Methods: A total of 93 women undergoing COH with GnRH agonist and FSH was studied prospectively. Serum levels of AMH, inhibin B, estradiol (E(2)), progesterone, testosterone and Delta(4)-androstenedione were measured when pituitary suppression was achieved (baseline), on days 6 and 8 of FSH treatment, and on the day of hCG. The number of small (<12 mm) and large (>/=12 mm) antral follicles were estimated using ultrasound.

Results: Serum AMH levels declined progressively (baseline, 1.21 +/- 0.11 ng/ml; day 6, 0.91 +/- 0.09 ng/ml; day 8, 0.77 +/- 0.08 ng/ml; and day of hCG, 0.53 +/- 0.06 ng/ml), whereas-as expected-the other hormone levels increased during FSH treatment. Throughout COH, serum AMH levels correlated positively with the number of small but not large antral follicles, and with inhibin B serum levels. No correlation between AMH and the other hormones was observed.

Conclusions: Serum AMH levels decline gradually during multiple follicular maturation, probably reflecting the dramatic reduction in the number of small antral follicles due to COH, and confirming the scarce AMH expression by larger follicles.