What does progesterone do?

Question

What does progesterone do?

Answer 1

Progesterone keeps your uterus lined with a nice bed for the fertilised egg to implant in.  Yor ovary contiues to produce progesterone when you are pregnant - until the placenta takes over production in the 2nd trimester.  You need progesteron throughout pregnancy to ensure the uterus remains rich and nicely lined.

ETA : Basically the cycle is FSH (follicle stimulating hormone) is produced making a follicle release an egg from one of your ovaries, the egg leaves a "husk" behind called the corpus luteum - this corpus luteum produces progesterone and it also slowly decays over about 14 days.  However if it receives a signal (HCG) from the fertilised egg it stops decaying and continues to produce progesterone until the placenta takes over progesterone production.  If it doesn;t receive the signal by the 14 day it will drop production of progesterone and you will have your period because of the lack of progesterone.  Some women I believe have problems with the corupus luteum producing enough and need a little extra help with progesterone supplements.

Answer 2

It helps build your uterus strong and keeps the baby in.  Some people have to be put on extra progesterone through pregnancy to help their body.  I had to be on it.  

Answer 3

I had to be on it, too. My doctor told me it was to sustain my pregnancy because my body was not producing any Progesterone on its own. If that is the case with you, it will help you keep your baby and makes sure they continue to grow on schedule.