The native form of follicle-stimulating hormone is essential for the growth of mouse preantral follicles in vitro.

To assess whether the follicle-stimulating hormone (FSH) subunits observed in patients with gonadotroph adenomas (GA) can cause infertility, the effects of subunits and heterodimeric FSH on the in vitro follicle development were evaluated in mice. The partial forms of FSH in follicle culture did not induce development into pseudoantral follicles, whereas follicles cultured with native FSH developed into pseudoantral follicles and produced mature metaphase II oocyte. Therefore, intact FSH is needed for folliculogenesis, implying that production of FSH with a partial structure in GA may result in infertility.