Smoking in pregnancy in West Virginia: does cessation/reduction improve perinatal outcomes?

To determine if pregnant women decreasing/quitting tobacco use will have improved fetal outcomes. Retrospective analysis of pregnant smokers from 6/1/2006-12/31/2007 who received prenatal care and delivered at a tertiary medical care center in West Virginia. Variables analyzed included birth certificate data linked to intervention program survey data. Patients were divided into four study groups: <8 cigarettes/day-no reduction, <8 cigarettes/day-reduction, ≥8 cigarettes/day-no reduction, and ≥8 cigarettes/day-reduction. Analysis performed using ANOVA one-way test for continuous variables and Chi-square for categorical variables. Inclusion criteria met by 250 patients. Twelve women (4.8%) quit smoking; 150 (60%) reduced; 27 (10.8%) increased; and 61 (24.4%) had no change. Comparing the four study groups for pre-term births (<37 weeks), 25% percent occurred in ≥8 no reduction group while 10% occurred in ≥8 with reduction group (P = 0.026). The high rate of preterm birth (25%) in the non-reducing group depended on 2 factors: (1) ≥8 cigarettes/day at beginning and (2) no reduction by the end of prenatal care. Finally, there was a statistically significant difference in birth weights between the two groups: ≥8 cigarettes/day with no reduction (2,872.6 g) versus <8 cigarettes/day with reduction (3,212.4 g) (P = 0.028). Smoking reduction/cessation lowered risk of pre-term delivery (<37 weeks) twofold. Encouraging patients who smoke ≥8 cigarettes/day during pregnancy to decrease/quit prior to delivery provides significant clinical benefit by decreasing the likelihood of preterm birth. These findings support tobacco cessation efforts as a means to improve birth outcome.