It depends on your situation the likelyhood of having multiples w/ more embryos placed. In my situation i'm young and have conceived before so I was given a 1 in 3 chance of twins w/ two embryos, so I opted to transfer one blastocyst. Taking birth control before IVF depends on what protocol your on. I was on the "long" protocol so I did start w/ the birth control. Sorry this wasn't much help but everyone's different so the treatments different!

For me they told me the pill was just to get my cycle where they wanted it. They wanted it to fall in their "up-time" I don't know what the actual point of it is.

As far as the number of embryos you transfer, it does increase your chances of having multiples, but just because you transfer 2 doesn't mean they will both stick. At my clinic I know they won't transfer more than 2 unless you are over 35. I hope this helps!!

I was also put on the pill. I guess they have to be in control of what's happening with your body. Also, I had to get another prescription becasue of only 3 birth control pills. Apparently, I have to take the pill along with the Lupron injection for 5 days.
They are going to transfer 2 -- RE said 30% chance of both taking.
Good luck to you.

my clinic told me the same that I had to be on BCP for 2 weeks to get everything "ready" ... my Dr told me yesterday when I saw him that they will be putting in 2 embies and the chance of twins is 25%.

The other posts are right on the money - the more embroys that are put back the higher your chances of multiple births. The BC pills are the way that the clinic gets you on their schedule, they need your cycle to jive with their schedule. Also the BC makes it easier to predict your bodies phases so they know when you should start the different meds and how long you should take them, etc.

Thanks for all your help. I feel a little better knowing what the purpose of bcp are for!!!! THANKS

My RE made me sign a paper before we started ANY treatment about how many embryos they transfer...because the more they transfer, the more likelihood that some will implant. But, the more they transfer the more COULD implant. If you transfer 5, you have an increased chance of becoming pregnant, but you also have an increased chance of becoming pregnant with 5!!! Then, you have to decide what to do. If you want to stay pregnant with 5, you have VERY increased risk of miscarraige, or very pre-term babies, and all the difficulties THAT brings. Or, you can have selective reduction. That entails them aborting some of the embryos to facilitate a healthier pregnancy. There are also risks involved with that, and personal ethical issues. It is a complicated choice, and one that is very personal. Your RE should really talk to you about risks, benefits, and personal choices before you even start. Good luck!!!

The quality of the embryos also plays a factor in them implanting. I had 3 transferred and had a single birth. At the time I was 31 years old.