I had a baby 2 years after graduation. I pledged my junior year. I never could have completed the process when I was pregnant. Especially the first few months of my pregnancy. I see how people pull it off unnoticed because I didn't show for almost 8 months. I just don't think it is safe. Even though with MIP there are no real physical limitations, it would be difficult to participate fully. Or it would have been for me.
That is of course... my opinion. And we all know that opinions are like @$$-holes. Everyone has one... some of them stink.