As to the female factor, therapeutic solutions of diminished ovarian reserve (DOR), issues related to advanced maternal age, poor oocyte quality at any age, and polycystic ovarian syndrome (PCOS) converge to the use of growth hormone (GH) during ovarian stimulation and the choice of a personalized protocol of ovarian stimulation adapting the doses of FSH and LH to be administered according to the current FSH-to-LH ratio in serum at different sequential phases of the stimulation. This evidence concerns the gene PLOD1 and polycystic ovary syndrome.