4.4.2 Regulation of the Hypothalamic-Pituitary-Ovarian Axis Before and After Menopause (Animation) Reproductive Age -What is the positive feedback loop in the female reproductive system? -What is the mechanism by which estradiol affects pituitary secretion of FSH and LH? -What is the negative feedback loop in the female reproductive system? -How do estrogens and progestins affect GnRH pulsatility? Menopause -Does the pituitary remain responsive to GnRH in the postmenopausal female?