The effect of heavy prenatal alcohol exposure on adolescent body mass index and waist-to-height ratio at 12-13 years.

BACKGROUND Growing evidence suggests that prenatal alcohol exposure (PAE) has the potential to impact on a wide range of physical outcomes in offspring, including metabolism and body composition, although the evidence to-date is primarily from preclinical studies. The current clinical study examined the association between heavy PAE and indirect measures of adiposity in adolescence. METHODS Analyses drew on data from the Longitudinal Study of Australian Children, a national prospective cohort of children and their families from birth to adolescence. Participants included children with heavy PAE (≥70 g/week; n = 46), measured via maternal self-report of alcohol use during pregnancy and a comparison group of children without any PAE (n = 782), frequency matched on sex, ethnicity and socio-economic position. Body mass index (BMI) z-scores, waist-to-height ratios and proportion overweight/obese were calculated from height, weight and waist circumference measured at age 12-13 years. Two (PAE) × two (sex) ANCOVA and logistic regression models were performed, controlling for matching variables, adolescent age, pubertal status and birthweight; maternal age at birth and smoking during pregnancy. RESULTS Female adolescents with heavy PAE during late pregnancy had significantly higher BMI z-scores (M = 0.75, SD = 0.69) and proportion overweight/obese (38.5%) than females not exposed to any prenatal alcohol (M = 0.29, SD = 1.07, P = 0.04; 23.8%, P = 0.03, respectively). There was no significant effect of heavy PAE on male adolescent BMI z-scores and proportion overweight/obese or adolescent waist-to-height ratios (all P > 0.05). CONCLUSIONS Heavy PAE had a sex-specific effect on measures of adiposity in early adolescence, with girls more likely to have increased BMI and overweight/obesity status. Further longitudinal follow-up of children exposed to PAE is required to confirm if maternal alcohol consumption is a risk factor for later life obesity.