The current study was conducted to examine the association between maternal trans fatty acid intake during pregnancy and fetal growth. A prospective cohort study of pregnant women and their offspring were studied, including 1369 mother-child pairs. Trans fatty acid consumption was assessed using a validated semi-quantitative food-frequency questionnaire in each of the first and second trimesters of pregnancy. Fetal growth was estimated as the birth-weight-for-gestational-age (BW/GA) z value in infants born at term. No associations between first-trimester trans fatty acid consumption and fetal growth were observed. Total trans fatty acid consumption during the second trimester, on the other hand, was positively associated with the fetal growth z score (0.29 units; 95% CI: 0.07-0.51 units) for each 1% increment in energy from trans fatty acids as a replacement for carbohydrates. The associations were limited to the trans fatty acids 16:1t (0.12 units; 95% CI: 0.02-0.22 units) and 18:2tc (0.53 units; 95% CI: 0.09-0.96 units). The authors concluded that a higher maternal intake of trans fatty acids, especially 16:1t and 18:2tc, during the second trimester of pregnancy was associated with greater fetal growth. Am J Clin Nutr. 2011 Sep 14. PMID: 21918217
