Nicki,
I think the number of embies transferred is determined somewhat by your age. When I first starting seeing my RE, he told me that he would not transfer more than 3 embies. But after my failed first IVF and prodding my by embryologist, we transferred 5 embies on the 2nd IVF.
I am 42 years old and the odds of a 42 year old giving birth to more than twins, using her own eggs, is very slim. My doctor is conservative in that he will not even freeze embies, instead he freezes eggs only. We fertilized 8 eggs and 5 embies made it to transfer, so we transferred 5. I did not get pregnant during that IVF, believe it or not. We had a miracle pregnancy while waiting to do a frozen cycle, as I still have 4 eggs in the freezer from my last IVF.
Regards,
Tammy