My only answer is that there is probably no real answer. You may get a lot of opinions and stories, but this is a question best left to a medical professional.
I once worked in an office where we had four women who were pregnant and the due dates were about six weeks apart. I learned more about child birth that I needed to know (my son is adopted). They kept talking about what they were and were not going to let the doctor do and they were quoting different articles, books, etc. (First child for all four). One day, they were all near my desk and I asked them, that wouldn't it be better to just trust the doctor, they were all going to the same one, who had an excellent reputation and had delivered hundreds of babies. This does not answer your question. It shows my belief in going to people who might really know the answers.