It speeds up contractions and makes it go faster. They wont make u get it if u go into labor but if u dont deliver after so long they will do a c section so they might encourage it after so long to avoid a c section.
Contractions are what dilate you. When youre around 35/36wks you actually start having real labor contractions known as early labor that most women do not notice or mistake for BH. Contrsctions are what cause the cervix to soft, open, and dilate. The more intense contractions get, the more they are opening up your cervix. If your contractions do not gain intensity fast enough or even at all then your dilation can stall out or take much longer than desired (hence why some women carry past 40wks). This is why pitocin is used. It forces the muscles to contract at a rate the nursing staff chooses. They will start the drip out slow and then increase it usually in increments of 30min. As the amount of pitocin increases, the stronger the contractions become and the further along your dilation should go. My pitocin started at a 2 and was increasd by 2 every 30 min until I hit 16. The level can go all the way up to 20. Usually if there are not the desired results by 16/18 the dr will discuss other options of birth such as c-section with you. But this will not be a problem if the contractions are moving your dilation along steadily :). Sorry so long but hopefully this helps.
Oh if you dont dilate but are contracting, then all that is happening is baby is bsing squeezed in place which can cut off their breathing and blood circulation over time.
@ladybeeley No that explains so much! I did not realize it was a timed thing that slowly increased as needed. I thought it was more like one big dose? FTM obviously :) I just hear some women going into labor, then saying they started it, and I wondered what the reasoning was. How you explained it makes much more sense to me now.