Which follicles make the most anti-Mullerian hormone in humans? Evidence for an abrupt decline in AMH production at the time of follicle selection

Anti-Müllerian hormone (AMH) is exclusively produced by granulosa cells (GC) of the developing pre-antral and antral follicles, and AMH is increasingly used to assess ovarian function. It is unclear which size follicles make the most AMH (total content) and are the main contributors to circulating AMH concentrations. To determine AMH gene expression in GC (q-RT-PCR) and follicular AMH production (Elisa and RIA) in relation to follicular development, 87 follicles (3-13 mm diameter) including both GC and the corresponding follicular fluid (FF) were collected in connection with fertility preservation of human ovaries. Further, follicle number and diameter, graded in 1 mm increments, were determined by 3D ultrasound in 113 women in their natural menstrual cycle to determine follicle number and diameter in relation to circulating AMH levels. This study demonstrates for the first time a positive association between AMH gene expression in human and both total follicular fluid AMH (P