CHOLESTEROL, CAROTENE AND BIRTHWEIGHT IN SMOKING MOTHERS

Abstract

It has been suspected that nutrition during pregnancy might counteract the adverse effects of smoking on birthweight (BWT). In our previous prospective studies of ∼2100 mothers, 47% were smokers who had 63% of the babies with BWT below our median (3300g). A prospective, randomized, controlled trial of a food supplement (WIC) from 19 weeks to term in 410 of these free-living mothers led to increased mean BWT +91g (p=0.039), which was greater in smokers (+115g, p=0.034), taking into account sex, gestational age, race, prenatal visits. In 288 mother/baby pairs multiple regression analysis revealed an interaction between maternal midpregnancy (19 weeks) plasma levels of cholesterol (chol), β carotene (βC) and smoking on BWT (p=0.017). Prospective data on the interactive effects of βC, chol and smoking on BWT apparently have not previously been noted. High βC (> 116 μg/dl) and low chol levels (< 150 mg/dl) were associated with significantly larger babies (+ ∼500g) in the smokers. If βC levels remained high from 19 to 36 weeks of gestation, heavy smokers delivered large babies. If βC levels decreased, the babies were small. In nonsmokers, no interaction between these nutrients on BWT was detected, but BWT was ∼300g more with higher chol, i.e., from 116 to 272 mg/dl at midpregnancy, at all levels of βC. We conclude that certain plasma levels of β carotene and cholesterol in smokers might counteract the adverse effect of smoking on fetal growth.