AMSTERDAM, THE NETHERLANDS. Infants born with low birth weight and those who are small for their gestational age (SGA) are at increased risk for being sickly and even dying as infants. Long-term they are at increased risk for metabolic and cardiovascular diseases. Adequate maternal nutrition has repeatedly been shown to be essential for optimum fetal growth, but it is not clear exactly which nutrients are most important. Dutch researchers now weigh in with a study aimed at determining the effects of common fatty acids on birth weight and SGA.
The study involved 3704 pairs of mothers and newborn infants enrolled in the Amsterdam Born Children and their Development (ABCD) study. All mothers completed food frequency questionnaires and gave blood samples around week 12 of their pregnancy. Analysis of the phospholipid phase of blood plasma revealed that mothers with low concentrations of omega-3 fatty acids and the omega-6 fatty acid, DGLA (dihomo-gamma-linolenic acid or eicosatetraenoic acid) gave birth to infants with significantly lower birth weights. Women with high levels of other omega-6 fatty acids and the main trans-fatty acid found in the diet, elaidic acid, also gave birth to infants with lower birth weights. Similar associations were found for SGA.
After adjusting for possible confounding variables, the researchers conclude that low maternal plasma concentrations of eicosatetraenoic acid, eicosapentaenoic acid (EPA) and DGLA, and high concentrations of arachidonic acid are associated with reduced fetal growth, lower birth weight, and a 40-50% increase in risk of SGA. They suggest that the established beneficial effect of fish oil supplementation (EPA and DHA) on pregnancy duration, in combination with their own results, points to the importance of fatty acid supplementation as a preventive option at all phases of pregnancy.
van Eijsden, M, et al. Maternal n-3, n-6, and trans fatty acid profile early in pregnancy and term birth weight: a prospective cohort study. American Journal of Clinical Nutrition, Vol. 87, 2008, pp. 887-95