CYP19A1 and Infertility: When GC from preovulatory follicles prior to ovulation induction were challenged by similar concentrations of FSH and LH, aromatase in vitro induction was clearly biggest after stimulation with LH, and in connection with ovarian stimulation for infertility treatment it has been shown that just a modest addition of LH-like activity results in a pronounced augmentation of estradiol.