Basal Serum Level of Δ4-Androstenedione Reflects The Ovaries’ Ability to Respond to Stimulation in IVF Cycles: Setting Up A New Reliable Index of Both Ovarian Reserve and Response

J Assist Reprod Genet.

Baseline serum Δ4-A, presumably crucial for ensuring a regular follicular growth, is a reliable marker of ovarian response to stimulation. Since the ovarian capacity to respond to gonadotropins does not depend exclusively on the presence of follicles, we suggest a new index, the G-index, able to contemplate both the ovarian reserve and the Δ4-A level.