Placental transfer of fatty acids and fetal implications

Abstract

Considerable amounts of long-chain polyunsaturated fatty acids (LC-PUFAs), particularly arachidonic acid and docosahexaenoic acid (DHA, 22:6n-3), are deposited in fetal tissues during pregnancy; and this process is facilitated by placental delivery. Nevertheless, the mechanisms involved in LC-PUFA placental transfer remain unclear. Stable isotope techniques have been used to study human placental fatty acid transfer in vivo. These studies have shown a significantly higher ratio of (13)C-DHA in cord to maternal plasma compared with other fatty acids, which reflects a higher placental DHA transfer. In addition, a selective DHA accumulation in placental tissue, relative to other fatty acids, has been reported. The materno-fetal transfer of fatty acids is a slow process that requires ≥12 h. A high incorporation of dietary (13)C-DHA into maternal plasma phospholipids appears to be important for placental uptake and transfer. DHA in cord blood lipids correlates with placental messenger RNA expression of fatty acid transport protein (FATP)-4, compatible with a role of FATP-4 in DHA transfer. Impaired materno-fetal LC-PUFA transport has been proposed in pregnancies complicated by abnormal placental function (eg, due to gestational diabetes mellitus or intrauterine growth restriction), which should be addressed in future studies. Given that placental DHA transfer is important for child outcomes, elucidation of its potential modulation by transport mechanisms, maternal diet, and disease appears to be important.

Effects of maternal n-3 fatty acid supplementation on placental cytokines, pro-resolving lipid mediators and their precursors

“…Placental SPMs and n-3 PUFA supplementation (Haggarty et al 1999, Duttaroy 2009, Larque et al 2011. Neonatal and maternal plasma DHA levels are strongly correlated (Sakamoto & Kubota 2004), and our present study has also found significant positive correlations between placental DHA and maternal and cord blood DHA levels, as well as correlations between maternal DHA and SPM precursor levels.…”

“…EPA, linoleic acid and linolenic acid), cord blood levels (as % total fatty acids) are maintained at similar or lower levels than maternal plasma, consistent with limited passive diffusion across the placenta (Larque et al 2011). On the other hand, relative levels of other fatty acids in cord blood (e.g.…”

“…On the other hand, relative levels of other fatty acids in cord blood (e.g. DHA, dihomo-g-linoleic acid and arachidonic acid) are higher than maternal levels and show a greater degree of independence (Berghaus et al 1998, Haggarty et al 1999, Herrera et al 2004, Sakamoto & Kubota 2004, Larque et al 2011). These differences can be explained by selective placental transfer of maternal fatty acids and foetal de-novo fatty acid synthesis and metabolism Figure 3 Cytokine mRNA expression in placental tissues from n-3 PUFA-supplemented pregnancies or controls.…”

Maternal Magnesium Deficiency in Mice Leads to Maternal Metabolic Dysfunction and Altered Lipid Metabolism with Fetal Growth Restriction

“…In addition, previous studies have revealed the correlations between low maternal n-3 and n-6 FA plasma concentrations and poor fetal growth (52) and between maternal dietary n-3:n-6 FA ratios and childhood brain development (53). The fetus relies on the transplacental transport of maternally derived DHA (6,54), which forms a maternal-to-fetal gradient favoring the fetus (55). DHA delivery to the fetus could be compromised by the 86% reduction in maternal liver DHA after Mg deficiency.…”

Placental regulation of fetal nutrient supply

“…Lipids are transferred because the fetus requires essential linoleic and a-linolenic acid, and additionally long-chain polyunsaturated fatty acids (LC-PUFAs) to match the in-utero accretion rate especially during the brain growth spurt. It has been demonstrated in pregnant women in vivo, using labeled fatty acids with stable isotopes, the preferential placental uptake and transfer of LC-PUFAs from the mother to the fetus with respect to other fatty acids, and specially for docosahexaenoic acid (DHA; n-3 LC-PUFA) [14,15]. This selective LC-PUFA transfer highlights the relevance of the placenta for the fatty acid transfer.…”