I just spoke to my dentist about this even though i'm not pregnant yet there is always the possibility now that we are trying and i need to have some fillings done. he said there is no known link to anything but prefers to wait until around the 5-6months as you are past the first trimester stage and not yet in the 3rd tri where you could go into early labour, this is just what my dentists said though i am sure they all have different opinions on things so i'd just ask your dentist what they think.