Fatty Acids in Obese Pregnancies: Maternal and Child Outcomes

Maternal obesity has implications on the health of future generations by early life programming. The mother is usually the main source of nutrients for the fetus and neonate, hence her nutritional status is crucial for child development. Fatty acids (FAs), especially long chain polyunsaturated fatty acids (LC-PUFAs), are key nutrients in fetal growth and development. Since these nutrients are known to be altered by conditions such as obesity, maternal obesity could impair fetal/neonatal FA supply, and consequently child outcomes. This thesis presents 4 manuscripts about the influence of maternal pre-pregnancy weight on FA quality and concentrations, along with the implications on maternal and child outcomes. We studied mother-child pairs selected from the total participants in the observational PREOBE cohort study and divided them into 4 groups according to maternal pre-pregnancy body mass index (BMI) and gestational diabetes status; 1) normal-weight, overweight, obese and gestational diabetic. We investigated if FADS and ELOVL genetic variants were associated with pre-pregnancy BMI or affected PUFA levels in plasma of pregnant women. We found that minor allele carriers of FADS1 and FADS2 SNPs had an increased risk for obesity and that the effects of genotype on plasma FA concentrations differed by maternal pre-pregnancy weight status. Enzymatic activity and FA levels were reduced in normal-weight women who were minor allele carriers of FADS SNPs; these reductions were not significant in overweight/obese participants. This suggests that women with a BMI>25 are less affected by FADS genetic variants in this regard. In the presence of FADS2 and ELOVL2 SNPs, overweight/obese women showed higher n-3 LC-PUFA production indexes in plasma than those women in the normal-weight group, but this was not enough to obtain a higher n3 LC-PUFA concentration. We also analyzed the differences in colostrum PUFA composition according to maternal pre-gestational BMI and FADS genotype. A high maternal pre-pregnancy BMI was associated with altered FA levels in colostrum, nevertheless FADS genotypes modulated these results. Minor allele carriers resulted with decreased enzymatic activity and PUFA levels only in normal-weight individuals, making their FA levels similar to those of overweight/obese women. Therefore, FADS genetic variation in overweight/obese women had a different impact, possibly improving their FA status. We also found that dietary intake of DHA in late pregnancy