When estrogen surges to create the LH surge prior to ovulation, what happens to FSH? It makes sense that when estrogen (+) feedback results in increased GnRH sensitivity of the AP and then BOTH LH and FSH would increase. If you look at any hormone level tracing, you will see this. BRS Phys explains it this way. HOWEVER.... Goljan and First Aid say the increased estrogen negatively feedbacks on FSH? They both say this multiple times, but then show the standard tracing where FSH levels increase right along with LH levels! Can some expert sdner clear this issue up por favor.