A Comprehensive Study of Dietary and Lifestyle Correlates of Erythrocyte Membrane Fatty Acids and Oxidative Stress and Their Association with Maternal and Neonatal Outcomes

Background: Erythrocyte fatty acid (FA) and oxidative stress levels are influenced by a range of factors. The aim of this study was to evaluate erythrocyte FA profiles and oxidative stress markers and their relationships with each other, nutrition, lifestyle, gestational age, and pregnancy outcomes in pregnant Latvian women. Methods: A total of 74 pregnant and postpartum women were cross-sectionally examined. Dietary intake was assessed using a validated food frequency questionnaire; erythrocyte FA composition was analyzed using gas chromatography with a flame ionization detector; and oxidative status was assessed based on Ferric Reducing Antioxidant Power (FRAP) assays, glutathione peroxidase (GPx) activity, and selenoprotein P (SEPP1) and malondialdehyde (MDA) levels. Results: Dietary fats constituted 42.0% of the total caloric intake. Saturated fatty acids (SFAs) predominated in erythrocytes (55.7%), with the highest concentration observed for 16:0. Although multiple significant correlations between dietary factors and laboratory parameters were identified, none remained significant after correction for multiple comparisons. Erythrocyte 18:3, n-3 was significantly associated with FRAP (p < 0.05). Gestational complications and age did not affect biochemical parameters (p > 0.05), though gestational age correlated with MDA (r = 0.377, p < 0.05) and pre-pregnancy body mass index (BMI) with MUFAs (r = 0.373, p < 0.01). The FA composition differed depending on smoking status and alcohol consumption. Conclusions: Given the exploratory nature of this study, findings should be interpreted with appropriate caution. Several associations retained statistical significance following correction for multiple comparisons, namely between erythrocyte 18:3, n-3 and FRAP, alcohol consumption and smoking with erythrocyte fatty acid profiles, maternal age and plasma MDA concentrations, and pre-gestational BMI and MUFA levels. The remaining associations did not withstand correction and should therefore be regarded as hypothesis-generating, warranting confirmation in larger, adequately powered, confirmatory studies.