I was doing a search of the prenatal that I'm going to be filling a prescription for to make sure it was the one I wanted. (My RE gave me a whole bag full of different samples, and I wanted to make sure I was getting the one I liked.) In my search, I came across this interesting tidbit.
You might want to check it out, and if your prenatal vitamin is on there, contact your doctor. I've left a message for my nurse, but probably won't hear back from her until later today.