what hormone is most important in the proliferative phase of the uterine cycle
Menstrual cycle The proliferative phase is the second phase of the uterine cycle when estrogen causes the lining of the uterus to grow, or proliferate, during this time.[81] As they mature, the ovarian follicles secrete increasing amounts of estradiol, and estrogen. The estrogens initiate the formation of a new layer of endometrium in the uterus, histologically identified as the proliferative endometrium. The estrogen also stimulates crypts in the cervix to produce fertile cervical mucus, which may be noticed by women practicing fertility awareness.[101]
Follicular phase The time from recruitment of tertiary stage follicles to ovulation, is normally about two weeks, comprising days 1-14 of an idealized 28-day menstrual cycle. However, it is common for the follicular phase to last much longer, as sometimes no dominant follicle is selected. In this case, more tertiary stage follicles are usually recruited, and the process begins again. One study of women with regular menstrual cycles found that none of them ovulated after the first wave of follicle development: 68% of cycles showed ovulation after the second wave, while 32% of cycles showed ovulation after the third wave.[12] Fertility awareness sources may refer to multiple waves of follicular development as a split peak because of the characteristic pattern of cervical mucus changes that is sometimes observed.[13][unreliable medical source?]