Effect of placental function on fatty acid requirements during pregnancy

Abstract

The fetus has an absolute requirement for the n-3/n-6 fatty acids and docosahexaenoic acid (22:6 n-3; DHA) in particular is essential for the development of the brain and retina. Most of the fat deposition in the fetus occurs in the last 10 weeks of pregnancy. The likely rate of DHA utilisation during late pregnancy cannot be met from dietary sources alone in a significant proportion of mothers. De novo synthesis makes up some of the shortfall but the available evidence suggests that the maternal adipose tissue makes a significant contribution to placental transport to the fetus. The placenta plays a crucial role in mobilising the maternal adipose tissue and actively concentrating and channelling the important n-3/n-6 fatty acids to the fetus via multiple mechanisms including selective uptake by the syncytiotrophoblast, intracellular metabolic channelling, and selective export to the fetal circulation. These mechanisms protect the fetus against low long-chain polyunsaturated fatty acid (LCPUFA) intakes in the last trimester of pregnancy and have the effect of reducing the maternal dietary requirement for preformed DHA at this time. As a result of these adaptations, small changes in the composition of the habitual maternal diet before pregnancy are likely to be more effective in improving LCPUFA delivery to the fetus than large dietary changes in late pregnancy. There is little evidence that DHA intake/status in the second half of pregnancy affects visual and cognitive function in the offspring, but more studies are needed, particularly in children born to vegetarian and vegan and mothers who may have very low intakes of DHA.

Keratinocyte-specific Expression of Fatty Acid Transport Protein 4 Rescues the Wrinkle-free Phenotype in Slc27a4/Fatp4 Mutant Mice

“…1G), the cells that transport all substances between mother and fetus. Because embryos obtain lipids from the maternal circulation only in the form of nonesterified fatty acids (25,26), we hypothesized that embryos might experience essential fatty acid deficiency in the absence of placental FATP4 (7). Symptoms of essential fatty acid deficiency show many similarities to the Fatp4 mutant phenotype, including loss of barrier function, thickened epidermis, loss of skin elasticity, and loss of hair (27)(28)(29)(30).…”

Fatty Acids as Biocompounds: Their Role in Human Metabolism, Health and Disease - A Review. Part 2: Fatty Acid Physiological Roles and Applications in Human Health and Disease

“…Preferential transfer of LC PUFA (mainly DHA) is higher than EFA transfer 72,74 . The fetus depends on placental LC PUFA supply because fetal Δ6-and Δ5-desaturase activity is very low in utero, and the placenta 71,74 ). Various studies have shown that maternal plasma and red blood cell FA percentages were highly significantly correlated with fetal and neonatal FA (ref.…”

“…During late pregnancy, intestinal absorption of TAG is very efficient and TAG are carried in the form of chylomicrons in maternal plasma 70 . The function of the placenta and many physiological and metabolic adaptations taking place during pregnancy play a fundamental role in optimising the transport of FA to the fetus 71 . Complex mechanisms are involved in placental fatty acid transport 72 .…”

Supplementation with the omega-3 docosahexaenoic acid: influence on the lipid composition and fatty acid profile of human milk

“…According to Kolelzko et al 17 , the diet of lactating and pregnant women should provide a minimum of 200mg/day of DHA. However, it is difficult to establish a precise amount since the mother's ability to store this acid and synthesize it from its precursor may vary 15,18 .…”

“…Maternal DHA intake has a significant impact on its concentration in her plasma and milk 6,[8][9][10]14 . Supplementation with LC-PUFA, especially omega-3, during pregnancy and lactation favors the mental development of the child 10,15 .…”