There has been no studies on how safe tdap is for unborn babies and it is almost more experimental for the CDC than it is for protecting unborn babies. They do not even know if it will actually help protect the baby from whooping cough or not. Also pharmaceutical companies have a big hand in the CDC so I've always been a little sketched out by what they suggest. I'd rather not be a Guinea pig....I really don't think I'll be get ANY vaccinations while pregnant because there are indeed risks. I'm trusting my gut on this one...