Birth control pills contain synthetic estrogen and progesterone. How might these hormones prevent pregnancy?
1. They cause the corpus luteum to degenerate.
2. They keep the pituitary from secreting FSH and LH, so ovulation does not occur.
3. They cause the lining of the uterus to be sloughed off.
4 They trigger premature ovulation, before an egg is mature.
The negative feedback effect of estrogen and progesterone on gonadotropins will be responsible for this.