How does estrogen prevent ovulation?

Estrogen prevents ovulation primarily through its regulatory effects on the hypothalamus and pituitary gland. It inhibits the release of gonadotropin-releasing hormone (GnRH), which decreases the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This suppression of LH and FSH prevents the ovarian follicles from maturing and ovulating. Additionally, high levels of estrogen can create a negative feedback loop, further reducing the likelihood of ovulation.