Elevated estrogen levels before ovulation trigger a positive feedback loop stimulating FSH and LH release for ovulation.

“But then just prior to ovulation, the levels of estrogen and the levels of some other hormones from those eggs-- you have the eggs producing estrogen themselves-- gets high enough that it actually triggers a positive feedback loop on the pituitary.”

“the higher your estrogen is the increased libido that you're going to have and of course you see those Peak estrogen levels which are going to trigger that LH surge”

“when you have seen that estrogen at its high levels which it's only made from a mature follicle and it's very specific 200 pams per milliliter for 50 hours that's the brain's clue okay we must have a mature egg and it can send out that surge of LH or lutenizing hormone and now you ovulate”

“When estrogen is high enough for long enough, 200 picoggrams for 50 hours. And that's the level it'll tell the brain it's time to ovulate. The brain will send out a surge of LH.”

“we see this huge estrogen surge which causes luteinizing hormone to surge and luteinizing hormone as LH and that's another hormone that's secreted from the pituitary gland this LH surge causes an egg to be released”