Women who stop smoking spontaneously prior to prenatal care and predictors of relapse before delivery.

This study explores the experience of pregnant women who quit smoking prior to initiating prenatal care. These "spontaneous quitters" comprised 41% of a socioeconomically and ethnically diverse population of prepregnancy smokers enrolled in a health maintenance organization. Compared to women who were smoking at the start of prenatal care, spontaneous quitters had been lighter smokers, were less likely to have another smoker in their household, indicated a stronger belief in the harmful effect of maternal smoking, had a history of fewer miscarriages, and entered prenatal care earlier. Biochemical validation of smoking status over the course of pregnancy found that 21% of the spontaneous quitters relapsed prior to delivery. Characteristics reported at the first prenatal visit that were associated with maintenance included having achieved cessation for a longer period of time without smoking even a puff, higher self-efficacy for maintenance, stronger belief in the harmful effect of maternal smoking, primigravida, and greater frequency of nausea. The identification of spontaneous quitters and selected intervention for those at greatest risk of relapse is recommended for inclusion in routine prenatal care.