Omega 3 in pregnancy: the transfer of fatty acids to the fetus depends on the mother's genes

The amounts of Omega 3 that reach the fetus during pregnancy depend both on the mother’s genes and those of the baby. This was announced by Eva Lattka, researcher at the Helmholtz Zentrum in Munich (Germany), during the Eleventh European Nutrition Conference in Madrid (Spain). According to the results obtained by Lattka and colleagues, the genes involved encode the fatty acid desaturases (FADS), enzymes involved in the synthesis of Omega-3 and Omega-6 fatty acids. These same genes determine how these nutrients are processed during pregnancy.

Omega-3 from mother to child

The variants of the FADS genes that may be present in a cell are diverse. Previous studies have shown that the type of gene carried by the mother influences the proportion of different fatty acids present in the mother's blood. In particular, some variants are less active and their presence modifies the fatty acid content in maternal blood. Although during pregnancy the fetus takes the necessary Omega-3 for its development from the placenta via the umbilical cord, no previous research has revealed how FADS genes influence the presence of these molecules in the umbilical cord itself. The association between FADS gene variants and levels of DHA (docosahexaenoic acid), an important Omega-3 for the development of the baby's nervous system, has also not been fully clarified. For this reason, Lattka and her team decided to analyze the relationship between FADS genes and the amounts of fatty acids present in the plasma of the umbilical cord. The researcher explained that this latter is an indicator of fatty acid supply to the fetus during pregnancy.

Mother and child, the result depends on both

The study involved analyzing 17 known variants of the FADS genes in more than 4,000 pregnant women and their children. The fatty acid levels in the expectant mothers were determined by analyzing their red blood cells after the twentieth week of gestation. Finally, the association between the presence of different genetic variants and the amounts of Omega-6 and Omega-3 present at birth in the umbilical cord of more than 2,000 babies was evaluated. The statistical analysis, conducted by Colin Steer of the University of Bristol (UK), demonstrated that the amount of DHA present in the red blood cells of pregnant women depends on the FADS gene variant present. Moreover, the data indicate that the type of genes present in the mother can influence the DHA supply to the baby during pregnancy. Lattka specified that this effect is independent of the mother's diet. However, the analyses revealed that the amounts of fatty acids present in the umbilical cord depend on both maternal and fetal genes. In fact, while the genes present in the mother determine the precursor of the fatty acids that will be transferred to the baby, it is the baby’s genes that allow the production of a particular fatty acid. The researchers therefore concluded that DHA levels depend both on the metabolism of the mother and that of the fetus.