Cigarette smoking and low maternal weight gain in Medicaid-eligible pregnant women.

OBJECTIVES: Weight gain during pregnancy (termed maternal weight gain) is an important predictor of maternal and infant health. This analysis was conducted to examine if cigarette smoking during pregnancy was associated with low maternal weight gain, as defined by the Institute of Medicine's (IOM) recommendations, independent of caloric intake.
METHODS: The participants were 265 Medicaid-eligible, pregnant women. Data were self-reported. Low maternal weight gain was defined as gaining less than the IOM recommendation for a given prepregnancy body mass index (BMI). Logistic regression was used to determine if smokers had greater odds of low maternal weight gain independent of caloric intake.
RESULTS: Approximately 21% of the participants were self-reported smokers. No difference was observed in mean maternal weight gain between smokers and nonsmokers (14.4 kg vs. 13.9 kg, respectively, p = 0.80). However, a greater proportion of smokers were categorized as having low maternal weight gain compared with nonsmokers (35.7% vs. 31.1%). Unadjusted regression analysis showed that the odds of low maternal weight gain were 1.34 times greater for smokers than nonsmokers (odds ratio [OR] = 1.34, 95% confidence interval [CI] 0.73, 2.67). The OR did not materially change after adjustment for daily caloric intake, age, and length of gestation. In addition, the data suggest that the more cigarettes smoked, the higher the odds of having low maternal weight gain.
CONCLUSIONS: The results suggest that cigarette smoking is associated with low maternal weight gain, as defined by the IOM recommendations, independent of caloric intake.