Just because we went to baby class a few weeks ago do I have any clue about this...<br>
Here's my not-so-schnientific answer:<br>
Yes, you're right, it varies. They can vary the dose and variety of chemistry they introduce (pitocin, cytotec, etc). Some hospitals have chosen chemistry sets they like to use.<br>
It varies on how 'ready' the cervix is, how thin the uterus has become, etc. It can last minutes, it can last hours. Getting the dose right is tricky and can cause heavy contractions. If they induce and it doesn't work, they usually move to a c-section - not sure how long they'll usually wait though.<br>
The anesthesiologist who gave us the talk (obviuosly) was confident in his/their ability - it's a pretty proven technology. They induce if the baby is too big, if they believe the placenta is or will decline in it's ability to deliver the needed nutrients or if some time has passed since the water broke (which could lead to infection). Hope that helped. Sorry if this is TMI.