Longitudinal circulating concentrations of long-chain polyunsaturated fatty acids in the third trimester of pregnancy in gestational diabetes.

AIM: Gestational diabetes mellitus is a common complication of pregnancy. Long-chain polyunsaturated fatty acids (LCPUFA) are essential for fetal neurodevelopment. Docosahexaenoic acid (DHA) is the predominant n-3 LCPUFA in the brain and retina. Circulating absolute concentrations of total n-3 and n-6 LCPUFAs rise during normal pregnancy. It remains unclear whether gestational diabetes may affect the normal rise in circulating concentrations of LCPUFAs in the third trimester of pregnancy - a period of rapid fetal neurodevelopment. This study aimed to address this question. METHODS: In a prospective singleton pregnancy cohort, fatty acids in fasting plasma total lipids were measured at 24-28 and 32-35 weeks of gestation in women with (n = 24) and without gestational diabetes mellitus (n = 116). Fatty acid desaturase activity indices were estimated by relevant product-to-precursor fatty acid ratios. Dietary nutrient intakes were estimated by a food frequency questionnaire. RESULTS: Plasma absolute concentrations of total n-6 LCPUFAs rose significantly between 24-28 and 32-35 weeks of gestation in women with or without gestational diabetes, whereas total n-3 LCPUFAs and DHA concentrations rose significantly only in women without gestational diabetes (all P < 0.01). Delta-5 desaturase indices (20:4n-6/20:3n-6) were similar, but delta-6 desaturase indices (18:3n-6/18:2n-6) were significantly lower in women with gestational diabetes at 32-35 weeks of gestation. Dietary intakes of all fatty acids were comparable. CONCLUSION: The normal rise in circulating absolute concentrations of DHA and total n-3 LCPUFAs in the third trimester of pregnancy may be compromised in gestational diabetes, probably due to impaired synthesis or mobilization rather than dietary intake difference.

Impact of a cholesterol enriched diet on maternal and fetal plasma lipids and fetal deposition in pregnant rabbits.

Pregnancy is associated with a hypercholesterolemic and a hyperlipidemic state. The totality of the essential fatty acids and 50% of the lipids needed by the fetus are transferred by the placenta from the maternal circulation. The hypothesis of this study is that an augmentation of the maternal plasmatic cholesterol is modifying the fetal lipids accumulation and development during rabbit pregnancy. To demonstrate the impact of a cholesterol enriched diet on plasma lipids during rabbit's pregnancy and on their fetus, we have established two groups: control and hypercholesterolemic rabbits (fed with a 0.2% cholesterol diet). Blood samples were collected before mating and at each trimester of pregnancy for analysis of lipid fractions and their lipoproteins. Plasma analysis shows that starting the 10th day of pregnancy the concentration of total-cholesterol and lipoproteins decreases for both groups. We have demonstrated that for the hypercholesterolemic group, concentrations of total-cholesterol (631%) and lipoproteins are significantly higher at the end of pregnancy than those for the control group. For both groups, after 20 days of pregnancy, triglycerides metabolism was biphasic showing a significant increase followed by a diminution in their concentration. In both groups, free fatty acids increases significantly at the end of the pregnancy (537.5% for the control group and 462.5% for the hypercholesterolemic group). Furthermore, the offsprings of hypercholesterolemic dams manifest a lower birth weight (15.5%) than those of control group. Our results demonstrate that a cholesterol enriched diet modifies greatly the fetal development and lipid metabolism during rabbit's pregnancy. These modifications could be useful for the understanding of the interaction between diet and fetal development in rabbit and probably during human pregnancy.