 The purpose of this trial is to evaluate the safety and effectiveness of 2 mg nicotine gum in promoting smoking cessation during pregnancy. The design is a randomized, placebo controlled trial where subjects are randomized to nicotine gum 6 weeks ad libitum use followed by a 6 week taper or a matching placebo. Women who are doing well at the end of the trial will also be offered gum post-partum for relapse prevention. 