Why cannot a woman who is pregnant continue to ovulate?

[lioric]

Homework Statement

Why cannot a woman who is pregnant continue to ovulate?

Homework Equations

no equation
FSH matures the egg
LH releases egg

The Attempt at a Solution

I do know that during ovulation fsh matures the egg and Lh releases the egg and after that the remains of the folical which is corpus luteum produces progesterone which helps thicken the lining of the uterus and keep the woman from going into menstruation. And once that dies the placenta produces progesterone to keep the woman from menstruating.
My question is what about LH and FSH?
It should be low right? Because that will keep the follicles from maturing and ovulating

 

[.Scott]

Per the wiki article https://en.wikipedia.org/wiki/Luteinizing_hormone#cite_ref-7, pregnancy will keep Luteinizing hormone (LH) low.
Wiki cites a textbook for this.

So it would seem that pregnancy affects the cycle near its earliest source.

 

[lioric]

Per the wiki article https://en.wikipedia.org/wiki/Luteinizing_hormone#cite_ref-7, pregnancy will keep Luteinizing hormone (LH) low.
Wiki cites a textbook for this.

So it would seem that pregnancy affects the cycle near its earliest source.

Thank you very much

 

[TeethWhitener]

My question is what about LH and FSH?

LH and FSH both spike right around ovulation and then decrease. If an egg is fertilized, the blastocyst begins to secrete human chorionic gonadotropin (hCG) at around day 5 or 6 post-fertilization. This is functionally identical to LH, and thus maintains progesterone production by the corpus luteum which prevents menstruation. And, yes, eventually the corpus luteum degrades and the placenta takes over progesterone production--the trophoblast layer in the blastocyst that secretes hCG eventually becomes the placenta.

Interesting side note: most (all?) home pregnancy tests monitor hCG levels, since it's quite easy to detect even only a few weeks post-fertilization.