Is using Nicotine Gum safe for a pregnant woman?

Can somebody provide some insight for me regarding this? I am asking for my fiancee who is pregnant, smokes, and wants to quit. Her Doctor gave her nicotine gum a little while back, and she cannot remember if it was because she was pregnant. It seems as though by "googling" this topic I get mixed results.

I am hoping, more than anything, that maybe some pregnant women out there know for sure if nicotine gum is safe during pregnancy? Any doctor's on Answers today? )

Thank you.