The dropping levels of estrogen and progesterone seem to be the cause of the onset of menopause and its symptoms. What is the approximate number of primordial follicles in the ovary of a woman of age 50?

Less than 1000

Explanation:

Approximately at the age of 50, the number of follicles decreases significantly, a situation that causes the lose of the ability of the ovary to cycle normally, so steroid levels decrease. The follicles have the function of containing the oocytes, a small number of these follicles is an insufficient number to maintain the cyclic hormonal process necessary for menstruation.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.