Illustration of the blood levels of various hormones during the menstrual cycle
Rainy Cloud - السبت, 2009-06-27 16:28 | علم الجنين | الصور الطبية › أشكال توضيحية | المحتوى الطبي
Follicle-stimulating hormone (FSH) stimulates the ovarian follicles to develop and produce estrogens. The level of estrogens rises to a peak just before the luteinizing hormone (LH) surge. Ovulation normally occurs 24 to 36 hours after the LH surge. If fertilization does not occur, the blood levels of circulating estrogens and progesterone fall. This hormone withdrawal causes the endometrium to regress and menstruation to start again
So how the OCP " oral contraceptive " works???
OCP prevent estrogen surge => No LH surge => No ovulation
And If fertilization occurs, Estrogen will fall and progesterone still in a high level by "corpus luteum" which is stimulated by HCG from placenta