Associations of light and moderate maternal alcohol consumption with fetal growth characteristics in different periods of pregnancy: the Generation R Study.

BACKGROUND Excessive alcohol consumption during pregnancy has adverse effects on fetal growth and development. Less consistent associations have been shown for the associations of light-to-moderate maternal alcohol consumption during pregnancy with health outcomes in the offspring. Therefore, we examined the associations of light-to-moderate maternal alcohol consumption with various fetal growth characteristics measured in different periods of pregnancy. METHODS This study was based on 7333 pregnant women participating in a population-based cohort study. Alcohol consumption habits and fetal growth were assessed in early (gestational age <17.9 weeks), mid- (gestational age 18-24.9 weeks) and late pregnancy (gestational age > or =25 weeks). We assessed the effects of different categories of alcohol consumption (no; less than one drink per week; one to three drinks per week; four to six drinks per week; one drink per day and two to three drinks per day) on repeatedly measured fetal head circumference, abdominal circumference and femur length. RESULTS In total, 37% of all mothers continued alcohol consumption during pregnancy, of whom the majority used less than three drinks per week. We observed no differences in growth rates of fetal head circumference, abdominal circumference or femur length between mothers with and without continued alcohol consumption during pregnancy. Compared with mothers without alcohol consumption, mothers with continued alcohol consumption during pregnancy had an increased fetal weight gain [difference 0.61 g (95% confidence interval: 0.18, 1.04) per week]. Cross-sectional analyses in mid- and late pregnancy showed no consistent associations between the number of alcoholic consumptions and fetal growth characteristics. All analyses were adjusted for potential confounders. CONCLUSIONS Light-to-moderate maternal alcohol consumption during pregnancy does not adversely affect fetal growth characteristics. Further studies are needed to assess whether moderate alcohol consumption during pregnancy influences organ growth and function in postnatal life.