How Do Hormones Genetically Prepare the Egg for Fertilization?
Incredible genetic cellular changes take place in a woman’s developing eggs each month, beginning with the elevation of FSH at the start of menstruation. Very complex events are taking place in the egg during this monthly development and growth of the follicle. Furthermore, the release of LH stimulated by the estrogen surge at midcycle does much more than just cause ovulation. It finalizes the critical genetic preparation of the egg, without which fertilization would be impossible. Thus far, only a superficial description of what happens during a menstrual cycle has been given: (1) follicular growth and estrogen production in the first half, (2) ovulation at midcycle, hopefully with fertilization, and (3) preparation of the uterine lining for embryo implantation in the second half of the cycle, stimulated by the production of progesterone from the corpus luteum (newly formed from the ovulated follicle). But these events are only the outward signs of an intricate genetic preparation for
