[Follicular maturation, dizygotic twin conceptions and maternal age]

This note aims to given an interpretation of the "paradoxical" increase of dizygotic twin pregnancies (and more generally of multiple pregnancies) according to maternal age, when in parallel the number of growing follicles decreases strongly. From the analysis, through an allometric model, of the relative variations with age of the size of the various ovarian follicular compartments, it reinforces the hypothesis of the existence of an inhibition factor, whose level would depend on the size of the residual stock of follicles and which would act on one or several phases of the follicular development. It brings evidence for the major role that this factor might play in the regulation of the whole reproductive life of women (and probably other mammals).