The effect of n-3 LCPUFA supplementation on oxidative stress and inflammation in the placenta and maternal plasma during pregnancy

Exploring Maternal Diet-Epigenetic-Gut Microbiome Crosstalk as an Intervention Strategy to Counter Early Obesity Programming

Alterations in a mother's metabolism and endocrine system, due to unbalanced nutrition, may increase the risk of both metabolic and non-metabolic disorders in the offspring's childhood and adulthood. The risk of obesity in the offspring can be determined by the interplay between maternal nutrition and lifestyle, intrauterine environment, epigenetic modifications, and early postnatal factors. Several studies have indicated that the fetal bowel begins to colonize before birth and that, during birth and nursing, the gut microbiota continues to change. The mother's gut microbiota is primarily transferred to the fetus through maternal nutrition and the environment. In this way, it is able to impact the establishment of the early fetal and neonatal microbiome, resulting in epigenetic signatures that can possibly predispose the offspring to the development of obesity in later life. However, antioxidants and exercise in the mother have been shown to improve the offspring's metabolism, with improvements in leptin, triglycerides, adiponectin, and insulin resistance, as well as in the fetal birth weight through epigenetic mechanisms. Therefore, in this extensive literature review, we aimed to investigate the relationship between maternal diet, epigenetics, and gut microbiota in order to expand on current knowledge and identify novel potential preventative strategies for lowering the risk of obesity in children and adults.

Association of MTHFR (C677T, A1298C) and MTRR A66G polymorphisms with fatty acids profile and risk of neural tube defects

OBJECTIVE

This study aims to determine if 5,10-methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and methionine synthase reductase (MTRR A66G) gene polymorphisms were associated with fatty acid (FA) levels in mothers of fetuses with neural tube defects (NTDs) and whether these associations were modified by environmental factors.

METHODS

Plasma FA composition was assessed using capillary gas chromatography. Concentrations of studied FA were compared between 42 mothers of NTDs fetuses and 30 controls as a function of each polymorphism by the Kruskal-Wallis nonparametric test.

RESULTS

In MTHFR gene C677T polymorphism, cases with (CT + TT) genotype had lower monounsaturated FAs (MUFA) and omega-3 polyunsaturated FA (n-3 PUFA) levels, but higher omega-6 polyunsaturated FAs (n-6 PUFA) and omega-6 polyunsaturated FAs: omega-3 polyunsaturated FAs (n-6:n-3) ratio levels. In MTRR gene A66G polymorphism, cases with (AG + GG) genotype had lower MUFA levels, but higher PUFA and n-6 PUFA levels. Controls with (AG + GG) genotype had lower n-6 PUFA levels. In MTHFR gene C677T polymorphism, cases with smoking spouses and (CT + TT) genotype had lower MUFA and n-3 PUFA levels, but higher PUFA, n-6 PUFA, and n-6:n-3 ratio levels. Cases with (CT + TT) genotype and who used sauna during pregnancy had lower n-3 PUFA levels. In MTRR gene A66G polymorphism, cases with (AG + GG) genotype and who used sauna during pregnancy had higher PUFA and n-6 PUFA levels.

CONCLUSIONS

Further research is required to clarify the association of FA metabolism and (MTHFR, MTRR) polymorphisms with NTDs.

Advances in free fatty acid profiles in gestational diabetes mellitus

The morbidity of gestational diabetes mellitus (GDM) is increasing and is associated with adverse perinatal outcomes and long-term maternal and infant health. The exact mechanism underlying changes in plasma free fatty acid (FFA) profiles in patients with GDM is unknown. However, it is believed that changes in diet and lipid metabolism may play a role. Fatty acids contain many specific FFAs, and the type of FFA has different impacts on physiological processes; hence, determining changes in FFAs in individual plasma is essential. Alterations in FFA concentration or profile may facilitate insulin resistance. Additionally, some FFAs show potential to predict GDM in early pregnancy and are strongly associated with the growth and development of the fetus and occurrence of macrosomia. Here, we aimed to review changes in FFAs in women with GDM and discuss the relationship of FFAs with GDM incidence and adverse outcomes.

Atopic and non-atopic effects of fish oil supplementation during pregnancy

BACKGROUND

We recently conducted a double-blinded randomised controlled trial showing that fish-oil supplementation during pregnancy reduced the risk of persistent wheeze or asthma in the child by 30%. Here, we explore the mechanisms of the intervention.

METHODS

736 pregnant women were given either placebo or n-3 long-chain polyunsaturated fatty acids (LCPUFAs) in the third trimester in a randomised controlled trial. Deep clinical follow-up of the 695 children in the trial was done at 12 visits until age 6 years, including assessment of genotype at the fatty acid desaturase (FADS) locus, plasma fatty acids, airway DNA methylation, gene expression, microbiome and metabolomics.

RESULTS

Supplementation with n-3 LCPUFA reduced the overall risk of non-atopic asthma by 73% at age 6 (relative risk (RR) 0.27 (95% CI 0.06 to 0.85), p=0.042). In contrast, there was no overall effect on asthma with atopic traits (RR 1.42 (95% CI 0.63 to 3.38), p=0.40), but this was significantly modified by maternal FADS genotype and LCPUFA blood levels (interaction p<0.05), and supplementation did reduce the risk of atopic asthma in the subgroup of mothers with FADS risk variants and/or low blood levels of n-3 LCPUFA before the intervention (RR 0.31 (95% CI 0.11 to 0.75), p=0.016). Furthermore, n-3 LCPUFA significantly reduced the number of infections (croup, gastroenteritis, tonsillitis, otitis media and pneumonia) by 16% (incidence rate ratio 0.84 (95% CI 0.74 to 0.96), p=0.009).

CONCLUSIONS

n-3 LCPUFA supplementation in pregnancy showed protective effects on non-atopic asthma and infections. Protective effects on atopic asthma depended on maternal FADS genotype and n-3 LCPUFA levels. This indicates that the fatty acid pathway is involved in multiple mechanisms affecting the risk of asthma subtypes and infections.

TRIAL REGISTRATION NUMBER

NCT00798226.

Exon-intron split analysis reveals posttranscriptional regulatory signals induced by high and low n-6/n-3 polyunsaturated fatty acid ratio diets in piglets

Polyunsaturated fatty acids (PUFA), such as omega-6 (n-6) and omega-3 (n-3), play a vital role in nutrient metabolism, inflammatory response, and gene regulation. microRNAs (miRNA), which can potentially degrade targeted messenger RNAs (mRNA) and/or inhibit their translation, might play a relevant role in PUFA-related changes in gene expression. Although differential expression analyses can provide a comprehensive picture of gene expression variation, they are unable to disentangle when in the mRNA life cycle the regulation of expression is taking place, including any putative functional miRNA-driven repression. To capture this, we used an exon-intron split analysis (EISA) approach to account for posttranscriptional changes in response to extreme values of n-6/n-3 PUFA ratio. Longissimus dorsi muscle samples of male and female piglets from sows fed with n-6/n-3 PUFA ratio of 13:1 (SOY) or 4:1 (LIN), were analyzed in a bidirectional contrast (LIN vs. SOY, SOY vs. LIN). Our results allowed the identification of genes showing strong posttranscriptional downregulation signals putatively targeted by significantly upregulated miRNA. Moreover, we identified genes primarily involved in the regulation of lipid-related metabolism and immune response, which may be associated with the pro- and anti-inflammatory functions of the n-6 and n-3 PUFA, respectively. EISA allowed us to uncover regulatory networks complementing canonical differential expression analyses, thus providing a more comprehensive view of muscle metabolic changes in response to PUFA concentration.

Metabolic Interaction Between Folate, Vitamin B12, and Polyunsaturated Fatty Acids in Pregnancy

Fetal growth and development are influenced by maternal nutrition and gestational weight gain. Adequate intake of nutrients such as folate, vitamin B12, and docosahexaenoic acid (DHA) is essential for healthy fetal and placental development. Many countries have a national flour fortification program with folic acid (FA), together with pre-pregnancy supplementation of FA (400 μg/day) during the first trimester of pregnancy. The latter has been recommended by the WHO and adapted to local requirements by perinatal guidelines. On the other hand, in population studies, many women of childbearing age have vitamin B12 deficiency (<148 pmol/L), which can be additionally masked by high FA intake and maternal pregestational obesity. Under these conditions, these patients could be having pregnancies in a folate/vitamin B12 imbalance, which is associated with higher adiposity, insulin resistance, altered lipid metabolism, and low DHA levels in their offspring. However, if these neonatal consequences of maternal pregestational obesity and folate/vitamin B12 imbalance can be reverted by DHA supplementation during pregnancy has not been addressed. This chapter reviews the literature and exposes the current gaps in knowledge and challenges in maternal nutrition with a life-course perspective.

Association of placental fatty acid desaturase 2 (FADS2) methylation with maternal fatty acid levels in women with preeclampsia

INTRODUCTION

Biosynthesis of long-chain polyunsaturated fatty acids requires sequential activities of desaturases and elongases for conversion of fatty acid precursors to products. The delta-6 desaturase enzyme, encoded by FADS2 gene, is a rate limiting enzyme in this pathway. Alterations in D6D enzyme activity can lead to altered fatty acid profiles.

OBJECTIVES

To examine differences in placental DNA methylation (DNAm) and expression of FADS2 gene in preeclampsia women compared to normal women and their association with maternal variables (plasma fatty acids, desaturase enzyme index, blood pressure), placental weight and birth outcomes.

METHODS

DNAm and expression of FADS2 gene were examined in placentae of normotensive (n = 100) control and preeclampsia (n = 100) women using pyrosequencing and quantitative real-time PCR respectively. Women with preeclampsia included those delivering at term (n = 43, gestation ≥ 37 weeks; T-PE) or preterm (n = 57, gestation < 37 weeks; PT-PE). A total of 26 CpGs in FADS2 promoter and region around it, were analysed in two PCR reactions (region 1 and 2).

RESULTS

Out of 13 CpGs in region 1, significant hypermethylation was noted at CpG3 in T-PE (p = 0.03) and of 13 CpGs in region 2, CpG2 (p = 0.008), CpG11 (p = 0.04), CpG12 (p = 0.001) were hypomethylated and CpG13 (p = 0.001) was hypermethylated in preeclampsia group, as compared to controls. FADS2 expression was lower in PT-PE as compared to controls (p = 0.04). DNAm at various CpGs in the FADS2 were associated with maternal plasma FADS2 enzyme index and also associated with maternal fatty acid levels. However, we did not observe any association of DNAm with maternal blood pressure, placental weight and birth outcomes.

CONCLUSIONS

This study for the first time reports differential methylation of FADS2 and its association with impaired maternal fatty acid metabolism in preeclampsia and provides a mechanistic basis to our earlier observations of altered maternal LCPUFA levels in women with preeclampsia.

Low n-6/n-3 Gestation and Lactation Diets Influence Early Performance, Muscle and Adipose Polyunsaturated Fatty Acid Content and Deposition, and Relative Abundance of Proteins in Suckling Piglets

Elevated omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFAs) ratios in swine diets can potentially impose a higher risk of inflammatory and metabolic diseases in swine. A low ratio between the two omega PUFAs has beneficial effects on sows' and piglets' production performance and immunity status. At present, there are few studies on how sow nutrition directly affects the protein and fat deposition in suckling piglets. Two groups of sows were fed diets with high or low n-6/n-3 polyunsaturated ratios of 13:1 (SOY) and 4:1 (LIN), respectively, during gestation and lactation. Longissimus dorsi muscle and adipose tissue from newborn piglets, nourished only with sow's milk, were subjected to fatty acid profiling by gas chromatography-mass spectrometry (GC-MS) and to proteomics assays based on nano-liquid chromatography coupled to high-resolution tandem mass spectrometry (nLC-HRMS). Fatty acid profiles on both muscle and adipose tissues resembled the magnitude of the differences between fatty acid across diets. Proteomic analysis revealed overabundance of 4 muscle and 11 adipose tissue proteins in SOY compared to LIN in both piglet tissues. The detected overabundance of haptoglobin, an acute-phase protein, and the stimulation of protein-coding genes and proteins related to the innate immune response and acute inflammatory response could be associated with the pro-inflammatory role of n-6 PUFAs.

Omega-3 fatty acid supplementation and fecundability

STUDY QUESTION

Is self-reported use of omega-3 fatty acid supplements associated with fecundability, the probability of natural conception, in a given menstrual cycle?

SUMMARY ANSWER

Prospectively recorded omega-3 supplement use was associated with an increased probability of conceiving.

WHAT IS KNOWN ALREADY

In infertile women, omega-3 fatty acid intake has been associated with increased probability of pregnancy following IVF. In natural fertility, studies are conflicting, and no study of natural fertility has evaluated omega-3 fatty acid supplementation and fecundity.

STUDY DESIGN, SIZE, DURATION

Secondary data analysis of 900 women contributing 2510 cycles in Time to Conceive (TTC), a prospective, time to pregnancy cohort study from 2008 to December 2015.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 30-44 years, trying to conceive <3 months, without history of infertility were followed using standardized pregnancy testing. While attempting to conceive, women daily recorded menstrual cycle events and supplement and medication intake using the Cerner Multum Drug Database. Supplements and vitamins containing omega-3 were identified. Omega-3 use, defined as use in at least 20% of days in a given menstrual cycle, in each pregnancy attempt cycle was determined. A discrete-time Cox proportional hazards model was used to calculate the fecundability ratio.

MAIN RESULTS AND THE ROLE OF CHANCE

Women taking omega-3 supplementation were more likely to be younger, thinner, nulligravid, white and to take vitamin D, prenatal and multivitamins compared to women not taking omega-3s. After adjusting for age, obesity, race, previous pregnancy, vitamin D and prenatal and multivitamin use, women taking omega-3 supplements had 1.51 (95% CI 1.12, 2.04) times the probability of conceiving compared to women not taking omega-3s.

LIMITATIONS, REASONS FOR CAUTION

Our study was not a randomized controlled trial. The women who used omega-3 supplements may represent a more health-conscious population. We sought to address this by adjusting for multiple factors in our model. Additionally, the omega-3 fatty acid supplements that TTC participants used included multiple types and brands with varying dosages of omega-3 fatty acids. Women reported the type of supplement they were taking but not the concentration of omega-3s in that supplement. It is therefore not possible to compare dosing or a dose-response relationship in our study.

WIDER IMPLICATIONS OF THE FINDINGS

Omega-3 supplementation may present a feasible and inexpensive modifiable factor to improve fertility. Randomized controlled trials are needed to further investigate the benefits of omega-3 supplementation for women trying to conceive naturally.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by the Division of Reproductive Endocrinology and Infertility at the University of North Carolina at Chapel Hill, the NIH/NICHD (R21 HD060229-01 and R01 HD067683-01), and in part by the Intramural Research Program of the National Institute of Environmental Health Sciences (Z01ES103333). The authors declare that there is no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Maternal Fatty Acid Metabolism in Pregnancy and Its Consequences in the Feto-Placental Development

During pregnancy, maternal plasma fatty acids are critically required for cell growth and development, cell signaling, and the development of critical structural and functional aspects of the feto-placental unit. In addition, the fatty acids modulate the early stages of placental development by regulating angiogenesis in the first-trimester human placenta. Preferential transport of maternal plasma long-chain polyunsaturated fatty acids during the third trimester is critical for optimal fetal brain development. Maternal status such as obesity, diabetes, and dietary intakes may affect the functional changes in lipid metabolic processes in maternal-fetal lipid transport and metabolism. Fatty acids traverse the placental membranes via several plasma membrane fatty acid transport/binding proteins (FAT, FATP, p-FABPpm, and FFARs) and cytoplasmic fatty acid-binding proteins (FABPs). This review discusses the maternal metabolism of fatty acids and their effects on early placentation, placental fatty acid transport and metabolism, and their roles in feto-placental growth and development. The review also highlights how maternal fat metabolism modulates lipid processing, including transportation, esterification, and oxidation of fatty acids.

The Gestational Effects of Maternal Appetite Axis Molecules on Fetal Growth, Metabolism and Long-Term Metabolic Health: A Systematic Review

Increased maternal food intake is considered a normal pregnancy adjustment. However, the overavailability of nutrients may lead to dysregulated fetal development and increased adiposity, with long-lasting effects on offspring in later life. Several gut-hormone molecules regulate maternal appetite, with both their orexigenic and anorectic effects being in a state of sensitive equilibrium. The aim of this manuscript is to systematically review literature on the effects of maternal gut-hormone molecules on fetal growth and metabolism, birth weight and the later metabolic health of offspring. Maternal serum ghrelin, leptin, IGF-1 and GLP-1 appear to influence fetal growth; however, a lack of consistent and strong correlations of maternal appetite axis hormones with birth weight and the concomitant correlation with fetal and birth waist circumference may suggest that these molecules primarily mediate fetal energy deposition mechanisms, preparing the fetus for survival after birth. Dysregulated intrauterine environments seem to have detrimental, sex-dependent effects on fetal energy stores, affecting not only fetal growth, fat mass deposition and birth weight, but also future metabolic and endocrine wellbeing of offspring.

Fatty acids in normal and pathological pregnancies

Long chain fatty acids, namely omega-3 and omega-6, are essential fatty acids and are necessary for proper pregnancy progression and fetal growth and development. Maternal fatty acid consumption and release of fatty acids from lipid stores provide increased availability of fatty acids for the placenta to transport to the growing fetus. Both omega-3 and omega-6 fatty acids are then utilized for generation of signaling molecules, such as eicosanoids, and for promoting of growth and developmental, most notably in the nervous system. Perturbations in fatty acid concentration and fatty acid signaling have been implicated in three major pregnancy complications - gestational diabetes, preeclampsia, and preterm birth. In this review we discuss the growing literature surrounding the role of fatty acids in normal and pathological pregnancies. Differences in maternal, placental, and fetal fatty acids and molecular regulation of fatty acid signaling and transport are presented. A look into novel fatty acid-based therapies for each of the highlighted disorders are discussed, and may present exciting bench to bedside alternatives to traditional pharmacological intervention.

Maternal n-3 Polyunsaturated Fatty Acid Enriched Diet Commands Fatty Acid Composition in Postnatal Brain and Protects from Neonatal Arterial Focal Stroke

The fetus is strongly dependent on nutrients from the mother, including polyunsaturated fatty acids (PUFA). In adult animals, n-3 PUFA ameliorates stroke-mediated brain injury, but the modulatory effects of different PUFA content in maternal diet on focal arterial stroke in neonates are unknown. This study explored effects of maternal n-3 or n-6 enriched PUFA diets on neonatal stroke outcomes. Pregnant mice were assigned three isocaloric diets until offspring reached postnatal day (P) 10–13: standard, long-chain n-3 PUFA (n-3) or n-6 PUFA (n-6) enriched. Fatty acid profiles in plasma and brain of mothers and pups were determined by gas chromatography–mass spectrometry and cytokines/chemokines by multiplex protein analysis. Transient middle cerebral artery occlusion (tMCAO) was induced in P9-10 pups and cytokine and chemokine accumulation, caspase-3 and calpain-dependent spectrin cleavage and brain infarct volume were analyzed. The n-3 diet uniquely altered brain lipid profile in naïve pups. In contrast, cytokine and chemokine levels did not differ between n-3 and n-6 diet in naïve pups. tMCAO triggered accumulation of inflammatory cytokines and caspase-3-dependent and -independent cell death in ischemic-reperfused regions in pups regardless of diet, but magnitude of neuroinflammation and caspase-3 activation were attenuated in pups on n-3 diet, leading to protection against neonatal stroke. In conclusion, maternal/postnatal n-3 enriched diet markedly rearranges neonatal brain lipid composition and modulates the response to ischemia. While standard diet is sufficient to maintain low levels of inflammatory cytokines and chemokines under physiological conditions, n-3 PUFA enriched diet, but not standard diet, attenuates increases of inflammatory cytokines and chemokines in ischemic-reperfused regions and protects from neonatal stroke.

Long-chain polyunsaturated fatty acid (LC-PUFA) status in severe preeclampsia and preterm birth: a cross sectional study

Long-Chain Polyunsaturated Fatty Acid (LCPUFA) is essential throughout pregnancy, since deficiency of LPUFA may linked to obstetrical complications. This study aimed to investigate LCPUFA status in severe preeclampsia and preterm birth. A cross sectional study was conducted in 104 pregnant women, which divided into normal pregnancy, severe preeclampsia and preterm birth groups. Serum percentage and concentration of total LCPUFA, omega-3, alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), omega-6, linoleic acid (LA), and arachidonic acid (AA) were measured using gas chromatography/mass spectrometry. Receiver operating characteristic (ROC), bivariate and multivariate analysis were performed. Severe preeclampsia showed the highest concentration of total PUFA and the lowest DHA percentage, with significantly higher Omega-6/Omega-3 ratio (p = 0.004) and lower omega-3 index (p < 0.002) compared to control. Preterm birth showed the least omega-3 concentrations, with significantly low omega-6 derivates (LA (p = 0.014) and AA (p = 0.025)) compared to control. LCPUFA parameters have shown to increase the risk in both conditions, particularly ALA ≤ 53 µmol/L in preeclampsia with OR 5.44, 95%CI 1.16-25.42 and preterm birth with OR 4.68, 95%CI 1.52-14.38. These findings suggest that severe preeclampsia and preterm birth have an imbalance in LCPUFA status.

Placental Impact of Dietary Supplements: More Than Micronutrients

PURPOSE

Maternal nutrition is a key modifier of fetal growth and development. However, many maternal diets in the United States do not meet nutritional recommendations. Dietary supplementation is therefore necessary to meet nutritional goals. The effects of many supplements on placental development and function are poorly understood. In this review, we address the therapeutic potential of maternal dietary supplementation on placental development and function in both healthy and complicated pregnancies.

METHODS

This is a narrative review of original research articles published between February 1970 and July 2020 on dietary supplements consumed during pregnancy and placental outcomes (including nutrient uptake, metabolism and delivery, as well as growth and efficiency). Impacts of placental changes on fetal outcomes were also reviewed. Both human and animal studies were included.

FINDINGS

We found evidence of a potential therapeutic benefit of several supplements on maternal and fetal outcomes via their placental impacts. Our review supports a role for probiotics as a placental therapeutic, with effects that include improved inflammation and lipid metabolism, which may prevent preterm birth and poor placental efficiency. Supplementation with omega-3 fatty acids (as found in fish oil) during pregnancy tempers the negative effects of maternal obesity but may have little placental impact in healthy lean women. The beneficial effects of choline supplementation on maternal health and fetal growth are largely attributable to its placental impacts. l-arginine supplementation has a potent provascularization effect on the placenta, which may underlie its fetal growth-promoting properties.

IMPLICATIONS

The placenta is exquisitely sensitive to dietary supplements. Pregnant women should consult their health care practitioner before continuing or initiating use of a dietary supplement. Because little is known about impacts of many supplements on placental and long-term offspring health, more research is required before robust clinical recommendations can be made.

Impact of Maternal Obesity on the Metabolism and Bioavailability of Polyunsaturated Fatty Acids during Pregnancy and Breastfeeding

Prenatal and postnatal development are closely related to healthy maternal conditions that allow for the provision of all nutritional requirements to the offspring. In this regard, an appropriate supply of fatty acids (FA), mainly n-3 and n-6 long-chain polyunsaturated fatty acids (LCPUFA), is crucial to ensure a normal development, because they are an integral part of cell membranes and participate in the synthesis of bioactive molecules that regulate multiple signaling pathways. On the other hand, maternal obesity and excessive gestational weight gain affect FA supply to the fetus and neonate, altering placental nutrient transfer, as well as the production and composition of breast milk during lactation. In this regard, maternal obesity modifies FA profile, resulting in low n-3 and elevated n-6 PUFA levels in maternal and fetal circulation during pregnancy, as well as in breast milk during lactation. These modifications are associated with a pro-inflammatory state and oxidative stress with short and long-term consequences in different organs of the fetus and neonate, including in the liver, brain, skeletal muscle, and adipose tissue. Altogether, these changes confer to the offspring a higher risk of developing obesity and its complications, as well as neuropsychiatric disorders, asthma, and cancer. Considering the consequences of an abnormal FA supply to offspring induced by maternal obesity, we aimed to review the effects of obesity on the metabolism and bioavailability of FA during pregnancy and breastfeeding, with an emphasis on LCPUFA homeostasis.

Exploring the role of LC-PUFA metabolism in pregnancy complications

Maternal nutrition during pregnancy plays a significant role in growth and development of the placenta and influencing pregnancy outcome. Suboptimal nutritional status during early gestational period compromises the normal course of pregnancy leading to adverse maternal and fetal outcomes. Omega-3 and omega-6 long chain polyunsaturated fatty acids (LC-PUFA) are important for the growth and development of the placenta. Maternal fatty acids and their metabolites influence the normal course of pregnancy by regulating cell growth and development, cell signaling, regulate angiogenesis, modulate inflammatory responses and influence various structural and functional processes. Alterations in LC-PUFA and their metabolites may result in inadequate spiral artery remodeling or placental angiogenesis leading to structural and functional deficiency of the placenta which contributes to several pregnancy complications like preeclampsia, gestational diabetes mellitus, intrauterine growth restriction, and results in adverse birth outcomes. In this review, we summarize studies examining the role of fatty acids and their metabolites in pregnancy. We also discuss the possible molecular mechanisms through which LC-PUFA influences placental growth and development. Studies have demonstrated that omega-3 fatty acid supplementation lowers the incidence of preterm births, but its effect on reducing pregnancy complications are inconclusive.

Nutrition and Metabolic Adaptations in Physiological and Complicated Pregnancy: Focus on Obesity and Gestational Diabetes

Pregnancy offers a window of opportunity to program the future health of both mothers and offspring. During gestation, women experience a series of physical and metabolic modifications and adaptations, which aim to protect the fetus development and are closely related to both pre-gestational nutritional status and gestational weight gain. Moreover, pre-gestational obesity represents a challenge of treatment, and nowadays there are new evidence as regard its management, especially the adequate weight gain. Recent evidence has highlighted the determinant role of nutritional status and maternal diet on both pregnancy outcomes and long-term risk of chronic diseases, through a transgenerational flow, conceptualized by the Development Origin of Health and Diseases (Dohad) theory. In this review we will analyse the physiological and endocrine adaptation in pregnancy, and the metabolic complications, thus the focal points for nutritional and therapeutic strategies that we must early implement, virtually before conception, to safeguard the health of both mother and progeny. We will summarize the current nutritional recommendations and the use of nutraceuticals in pregnancy, with a focus on the management of pregnancy complicated by obesity and hyperglycemia, assessing the most recent evidence about the effects of ante-natal nutrition on the long-term, on either maternal health or metabolic risk of the offspring.

Maternal High Linoleic Acid Alters Placental Fatty Acid Composition

Fetal development is modulated by maternal nutrition during pregnancy. The dietary intake of linoleic acid (LA), an essential dietary n-6 polyunsaturated fatty acid (PUFA), has increased. We previously published that increased LA consumption during pregnancy does not alter offspring or placental weight but fetal plasma fatty acid composition; the developing fetus obtains their required PUFA from the maternal circulation. However, it is unknown if increased maternal linoleic acid alters placental fatty acid storage, metabolism, transport, and general placental function. Female Wistar-Kyoto rats were fed either a low LA diet (LLA; 1.44% of energy from LA) or high LA diet (HLA; 6.21% of energy from LA) for 10 weeks before pregnancy and during gestation. Rats were sacrificed at embryonic day 20 (E20, term = 22 days) and placentae collected. The labyrinth of placentae from one male and one female fetus from each litter were analyzed. High maternal LA consumption increased placental total n-6 and LA concentrations, and decreased total n-3 PUFA, alpha-linolenic acid (ALA), and docosahexaenoic acid (DHA). Fatty acid desaturase 1 (Fads1), angiopoietin-like 4 (Angptl4), and diacylglycerol lipase beta (Daglb) mRNA were downregulated in placentae from offspring from HLA dams. Maternal high LA downregulated the fatty acid transport protein 4 (Fatp4) and glucose transporter 1 (Slc2a1) mRNA in placentae. IL-7 and IL-10 protein were decreased in placentae from offspring from HLA dams. In conclusion, a high maternal LA diet alters the placental fatty acid composition, inflammatory proteins, and expressions of nutrient transporters, which may program deleterious outcomes in offspring.

H. Smith L, Puttonen H, Fyhr IM, Sävman K, Nilsson AK, Klevebro S. Docosahexaenoic Acid and Arachidonic Acid Levels Are Associated with Early Systemic Inflammation in Extremely Preterm Infants

Fetal and early postnatal inflammation have been associated with increased morbidity in extremely preterm infants. This study aimed to demonstrate if postpartum levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) were associated with early inflammation. In a cohort of 90 extremely preterm infants, DHA and AA in cord blood, on the first postnatal day and on postnatal day 7 were examined in relation to early systemic inflammation, defined as elevated C-reactive protein (CRP) and/or interleukin-6 (IL-6) within 72 h from birth, with or without positive blood culture. Median serum level of DHA was 0.5 mol% (95% CI (confidence interval) 0.2–0.9, P = 0.006) lower than the first postnatal day in infants with early systemic inflammation, compared to infants without signs of inflammation, whereas levels of AA were not statistically different between infants with and without signs of inflammation. In cord blood, lower serum levels of both DHA (correlation coefficient −0.40; P = 0.010) and AA (correlation coefficient −0.54; p < 0.001) correlated with higher levels of IL-6. Levels of DHA or AA did not differ between infants with and without histological signs of chorioamnionitis or fetal inflammation. In conclusion, serum levels of DHA at birth were associated with the inflammatory response during the early postnatal period in extremely preterm infants.

Association of vitamin D with fatty acids in pregnancy

Preeclampsia is a pregnancy complication, associated with an increased risk of maternal and neonatal morbidity and mortality. The etiology of preeclampsia is not yet fully understood, although the current literature indicates an up regulation of inflammatory mediators. Vitamin D is known to have anti-inflammatory properties and influence vascular function. Fatty acids are also known to regulate inflammation in pregnancy. This study was carried out to explore the association of maternal vitamin D and fatty acids in pregnancy. The present study includes 69 normotensive control (NC) and 50 women with preeclampsia (PE). Maternal and cord serum 25-hydroxyvitamin D [25(OH)D] levels were lower (p<0.01for both) in women with PE compared to NC women. Maternal plasma total polyunsaturated fatty acids (PUFA) levels were lower (p<0.05) while levels of total saturated fatty acids (SFA) and total monounsaturated fatty acids (MUFA) were higher (p<0.05 for both) in women with PE. Cord erythrocyte PUFA levels were higher (p<0.01) in PE women. Maternal 25(OH)D levels were negatively associated with maternal systolic and diastolic BP (p<0.01 for both). Maternal 25(OH)D levels were positively associated with maternal total PUFA (p<0.01) and negatively associated with maternal total SFA (p<0.05), total MUFA (p<0.01). This study for the first time demonstrates an association of maternal vitamin D with fatty acid levels in pregnancy. Our results suggest that vitamin D and fatty acids may work in concert to regulate fetal growth.

Serum omega-3 and omega-6 fatty acid concentrations and natural fertility

STUDY QUESTION

Are serum omega-3 and omega-6 essential fatty acid concentrations associated with the probability of conceiving?

SUMMARY ANSWER

There is no strong association between serum concentrations of omega-3 and omega-6 fatty acids and the probability of conceiving naturally.

WHAT IS KNOWN ALREADY

Omega-3 and omega-6 fatty acid serum concentrations have been shown to play an important role in reproduction in animal models, while conflicting results have been reported in human studies of infertile women. It is unknown to what extent omega fatty acid serum concentrations impact natural fertility.

STUDY DESIGN, SIZE, DURATION

A nested, case-control study was conducted consisting of 200 participants [fertile: conceived within 3 cycles of attempt (n = 50), subfertile: conceived within 4 and 12 cycles of attempt (n = 100) and infertile: did not conceive within 12 cycles of attempt (n = 50)] randomly selected from the Time to Conceive cohort, a prospective time-to-pregnancy study (2008 to 2015).

PARTICIPANTS/MATERIALS, SETTING, METHODS

In the Time to Conceive study, women aged 30-44 years who were trying to conceive for <3 months and had no history of infertility were recruited and followed until the end of their pregnancy or ~1 year of pregnancy attempt. For this study, serum collected early in the woman's pregnancy attempt was analysed for anti-Müllerian hormone (AMH) and omega-3 and omega-6 fatty acid concentrations by liquid chromatography-mass spectrometry. The primary outcome was a positive home pregnancy test. The secondary outcomes were miscarriage and serum AMH level. A discrete-time Cox proportional hazards model was used to estimate the fecundability ratio. The odds ratios for miscarriage were calculated using logistic regression. The association between serum omega fatty acid concentrations and AMH level (natural log transformed) was analysed using Pearson's Correlation.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 200 women provided 1321 cycles for analysis.Mean omega-3, omega-6 and omega-6:omega-3 ratios did not significantly differ between the fertile, subfertile and infertile groups. There were no associations (all fecundability ratios ~1.0) between pregnancy and individual omega-3 fatty acid concentrations, including alpha-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid, or omega-6 fatty acids, including linoleic acid (LA), dihommo-gamma linolenic acid and arachidonic acid. There was no significant association between any individual omega fatty acid serum concentration and the age-adjusted odds of miscarriage. No association was found between any serum omega fatty acid concentration and AMH.

LIMITATIONS, REASONS FOR CAUTION

This study is limited by the sample size. Omega-3 and omega-6 fatty acid concentrations were derived from serum provided at a single timepoint in the first cycle of enrollment. Serum concentrations may therefore not be representative of all critical timepoints in the menstrual cycle or throughout their attempts to conceive. Additionally, women enrolled in this study were 30 years of age and older, and therefore the findings may not apply to younger women.

WIDER IMPLICATIONS OF THE FINDINGS

These data would suggest that omega-3 and omega-6 serum levels are not associated with natural fertility or risk of miscarriage. However, due to the above-mentioned limitations, future investigation is still needed to determine whether omega-3 fatty acid supplementation may benefit women planning to conceive naturally.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Division of Reproductive Endocrinology and Infertility at the University of North Carolina at Chapel Hill, by the NIH/NICHD (R21 HD060229-01 and R01 HD067683-01) and, in part, by the Intramural Research Program of the National Institute of Environmental Health Sciences (Z01ES103333). Dr. Jukic received vitamin D supplements for a research study from Theralogix, Inc. The authors have no other conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Experimental drugs for the inhibition of preterm labor

INTRODUCTION

Preterm birth is the leading cause of neonatal morbidity and mortality globally and poses a substantial economic burden. Consequently, there is a need for the identification of therapeutic targets and novel experimental drugs for the inhibition of preterm labor to improve neonatal outcomes.

AREAS COVERED

The authors review the pathophysiology of labor and the inflammatory pathways underpinning it. The interruption of these pathways forms the basis of therapeutic targets to inhibit preterm labor. Current drugs available for the treatment of preterm labor are reviewed, followed by experimental drugs including toll-like receptor 4 (TLR-4) antagonists, cytokine suppressive anti-inflammatory drugs (CSAIDs), N-acetyl cysteine (NAC), Sulfasalazine (SSZ), tumor necrosis factor-alpha (TNF-α) antagonists, interleukin-1 receptor (IL-1) inhibitors, omega-3 polyunsaturated fatty acids and lipid metabolites, and the polyphenols.

EXPERT OPINION

A number of new therapeutic strategies for the prevention of preterm labor are being investigated. These have the potential to improve neurodevelopmental outcomes and survival in babies born preterm, reducing the economic and healthcare costs of caring for the complex needs of these children in the immediate and long term. It is likely that over the next decade there will be a new treatment option that targets the pathological inflammatory processes involved in preterm labor.

Update on oxidative stress and inflammation in pregnant women, unborn children (nasciturus), and newborns - Nutritional and dietary effects

The scientific background of perinatal pathology, regarding both mother and offspring, from the lipidomic perspective, has highlighted the possibility of identifying new, promising clinical markers of oxidative stress and inflammation, closely related to the normal development of unborn and newborn children, together with their application. In this regard, in recent years, significant advances have been achieved, assisted by both newly developed analytical tools and basic knowledge on the biological implications of oxylipins. Hence, in the light of this recent progress, this review aims to provide an update on the relevance of human oxylipins during pregnancy and in the unborn and newborn child, covering two fundamental aspects. Firstly, the evidence from human clinical studies and dietary intervention trials will be used to shed light on the extent to which dietary supplementation can modulate the lipidomic markers of oxidative stress and inflammation in the perinatal state, emphasizing the role of the placenta and metabolic disturbances in the mother and fetus. The second part of this article comprises a review of existing data on specific pathophysiological aspects of human reproduction, in relation to lipidomic markers in pregnant women, unborn children, and newborn children. The information reviewed here evidences the current opportunity to correct reproductive disturbances, in the framework of lipidomics, by fine-tuning dietary interventions.

Effects of first-generation in utero exposure to diesel engine exhaust on second-generation placental function, fatty acid profiles and foetal metabolism in rabbits: preliminary results

Atmospheric pollution has major health effects on directly exposed subjects but intergenerational consequences are poorly characterized. We previously reported that diesel engine exhaust (DE) could lead to structural changes in the placenta of in utero exposed rabbits (first generation, F1). The effects of maternal exposure to DE were further studied on second-generation (F2) rabbits. Pregnant F0 females were exposed to filtered, diluted DE (1 mg/m³, median particle diameter: 69 nm) or clean filtered air (controls) for 2 h/day, 5 days/week by nose-only exposure during days 3–27 post-conception (dpc). Adult female offspring (F1) were mated to control males: F1 tissues and F2 foeto-placental units were collected at 28 dpc and placental structure and gene expression (microarray) analysed. Fatty acid profiles were determined in foetal and maternal plasma, maternal liver and placenta. In F1, compared to controls, hepatic neutral lipid contents were increased in exposed animals without change in the blood biochemistry. In F2, the placental lipid contents were higher, with higher monounsaturated fatty acids and reduced pro-inflammatory arachidonic acid (AA), without placental structural changes. Conversely, the proportion of anti-inflammatory n-3 polyunsaturated fatty acids in F2 plasma was increased while that of AA was decreased. Gene set enrichment analyses (GSEA) of F2 placenta transcriptomic data identified that the proteasome complex and ubiquitin pathways genes were over-represented and ion channel function and inflammation pathways genes were under-represented in exposed animals. These preliminary results demonstrate that diesel engine exhaust exposure and in utero indirect exposure should be considered as a programming factor within the context of the DOHaD (Developmental Origins of Health and Disease) with a probable intergenerational transmission.

Effects of Arachidonic and Docosohexahenoic Acid Supplementation during Gestation in Rats. Implication of Placental Oxidative Stress

Arachidonic and docosahexaenoic acids (ARA and DHA) are important during pregnancy. However, the effects of dietary supplementation on fetal growth and oxidative stress are inconclusive. We aimed to assess the effect of high ARA and DHA diet during rat gestation on: (1) ARA and DHA availability in plasma and placenta, (2) fetal growth, and (3) placental oxidative stress, analyzing the influence of sex. Experimental diet (ED) was prepared by substituting soybean oil in the control diet (CD) by a fungi/algae-based oil containing ARA and DHA (2:1). Rats were fed with CD or ED during gestation; plasma, placenta, and fetuses were obtained at gestational day 20. DHA, ARA, and their precursors were analyzed in maternal plasma and placenta by gas chromatography/mass spectrophotometry. Fetuses and placentas were weighed, the proportion of fetuses with intrauterine growth restriction (IUGR) determined, and placental lipid and protein oxidation analyzed. ED fetuses exhibited lower body weight compared to CD, being >40% IUGR; fetal weight negatively correlated with maternal plasma ARA, but not DHA. Only ED female placenta exhibited higher lipid and protein oxidation compared to its CD counterparts; lipid peroxidation is negatively associated with fetal weight. In conclusion, high ARA during gestation associates with IUGR, through placental oxidative stress, with females being more susceptible.

Omega-3 fatty acid addition during pregnancy

BACKGROUND

Higher intakes of foods containing omega-3 long-chain polyunsaturated fatty acids (LCPUFA), such as fish, during pregnancy have been associated with longer gestations and improved perinatal outcomes. This is an update of a review that was first published in 2006.

OBJECTIVES

To assess the effects of omega-3 LCPUFA, as supplements or as dietary additions, during pregnancy on maternal, perinatal, and neonatal outcomes and longer-term outcomes for mother and child.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (16 August 2018), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing omega-3 fatty acids (as supplements or as foods, stand-alone interventions, or with a co-intervention) during pregnancy with placebo or no omega-3, and studies or study arms directly comparing omega-3 LCPUFA doses or types. Trials published in abstract form were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data, assessed risk of bias in trials and assessed quality of evidence for prespecified birth/infant, maternal, child/adult and health service outcomes using the GRADE approach.

MAIN RESULTS

In this update, we included 70 RCTs (involving 19,927 women at low, mixed or high risk of poor pregnancy outcomes) which compared omega-3 LCPUFA interventions (supplements and food) compared with placebo or no omega-3. Overall study-level risk of bias was mixed, with selection and performance bias mostly at low risk, but there was high risk of attrition bias in some trials. Most trials were conducted in upper-middle or high-income countries; and nearly half the trials included women at increased/high risk for factors which might increase the risk of adverse maternal and birth outcomes.Preterm birth < 37 weeks (13.4% versus 11.9%; risk ratio (RR) 0.89, 95% confidence interval (CI) 0.81 to 0.97; 26 RCTs, 10,304 participants; high-quality evidence) and early preterm birth < 34 weeks (4.6% versus 2.7%; RR 0.58, 95% CI 0.44 to 0.77; 9 RCTs, 5204 participants; high-quality evidence) were both lower in women who received omega-3 LCPUFA compared with no omega-3. Prolonged gestation > 42 weeks was probably increased from 1.6% to 2.6% in women who received omega-3 LCPUFA compared with no omega-3 (RR 1.61 95% CI 1.11 to 2.33; 5141 participants; 6 RCTs; moderate-quality evidence).For infants, there was a possibly reduced risk of perinatal death (RR 0.75, 95% CI 0.54 to 1.03; 10 RCTs, 7416 participants; moderate-quality evidence: 62/3715 versus 83/3701 infants) and possibly fewer neonatal care admissions (RR 0.92, 95% CI 0.83 to 1.03; 9 RCTs, 6920 participants; moderate-quality evidence - 483/3475 infants versus 519/3445 infants). There was a reduced risk of low birthweight (LBW) babies (15.6% versus 14%; RR 0.90, 95% CI 0.82 to 0.99; 15 trials, 8449 participants; high-quality evidence); but a possible small increase in large-for-gestational age (LGA) babies (RR 1.15, 95% CI 0.97 to 1.36; 6 RCTs, 3722 participants; moderate-quality evidence, for omega-3 LCPUFA compared with no omega-3. Little or no difference in small-for-gestational age or intrauterine growth restriction (RR 1.01, 95% CI 0.90 to 1.13; 8 RCTs, 6907 participants; moderate-quality evidence) was seen.For the maternal outcomes, there is insufficient evidence to determine the effects of omega-3 on induction post-term (average RR 0.82, 95% CI 0.22 to 2.98; 3 trials, 2900 participants; low-quality evidence), maternal serious adverse events (RR 1.04, 95% CI 0.40 to 2.72; 2 trials, 2690 participants; low-quality evidence), maternal admission to intensive care (RR 0.56, 95% CI 0.12 to 2.63; 2 trials, 2458 participants; low-quality evidence), or postnatal depression (average RR 0.99, 95% CI 0.56 to 1.77; 2 trials, 2431 participants; low-quality evidence). Mean gestational length was greater in women who received omega-3 LCPUFA (mean difference (MD) 1.67 days, 95% CI 0.95 to 2.39; 41 trials, 12,517 participants; moderate-quality evidence), and pre-eclampsia may possibly be reduced with omega-3 LCPUFA (RR 0.84, 95% CI 0.69 to 1.01; 20 trials, 8306 participants; low-quality evidence).For the child/adult outcomes, very few differences between antenatal omega-3 LCPUFA supplementation and no omega-3 were observed in cognition, IQ, vision, other neurodevelopment and growth outcomes, language and behaviour (mostly low-quality to very low-quality evidence). The effect of omega-3 LCPUFA on body mass index at 19 years (MD 0, 95% CI -0.83 to 0.83; 1 trial, 243 participants; very low-quality evidence) was uncertain. No data were reported for development of diabetes in the children of study participants.

AUTHORS' CONCLUSIONS

In the overall analysis, preterm birth < 37 weeks and early preterm birth < 34 weeks were reduced in women receiving omega-3 LCPUFA compared with no omega-3. There was a possibly reduced risk of perinatal death and of neonatal care admission, a reduced risk of LBW babies; and possibly a small increased risk of LGA babies with omega-3 LCPUFA.For our GRADE quality assessments, we assessed most of the important perinatal outcomes as high-quality (e.g. preterm birth) or moderate-quality evidence (e.g. perinatal death). For the other outcome domains (maternal, child/adult and health service outcomes) GRADE ratings ranged from moderate to very low, with over half rated as low. Reasons for downgrading across the domain were mostly due to design limitations and imprecision.Omega-3 LCPUFA supplementation during pregnancy is an effective strategy for reducing the incidence of preterm birth, although it probably increases the incidence of post-term pregnancies. More studies comparing omega-3 LCPUFA and placebo (to establish causality in relation to preterm birth) are not needed at this stage. A further 23 ongoing trials are still to report on over 5000 women, so no more RCTs are needed that compare omega-3 LCPUFA against placebo or no intervention. However, further follow-up of completed trials is needed to assess longer-term outcomes for mother and child, to improve understanding of metabolic, growth and neurodevelopment pathways in particular, and to establish if, and how, outcomes vary by different types of omega-3 LCPUFA, timing and doses; or by characteristics of women.

Associations of maternal immune response with MeHg exposure at 28 weeks' gestation in the Seychelles Child Development Study

PROBLEM

Maternal methylmercury (MeHg) exposure may be associated with immune response during pregnancy.

METHOD OF STUDY

In the high fish-eating Seychelles Child Development Study Nutrition Cohort 2, we examined the association between maternal MeHg, polyunsaturated fatty acids (PUFA), and immune markers (Th1:Th2; TNF-α, IL-1β, IFN-γ, IL-2, IL-4, IL-5, IL-10, MCP-1, TARC, sFlt-1, VEGF-D, CRP and IL-6) at 28 weeks' gestation. Linear regression examined associations between MeHg exposure and immune markers with and without adjustment for PUFA.

RESULTS

In all models, as MeHg concentrations increased, the Th1:Th2 ratio, total Th1 and individual Th1 (IL-1β, IL-2, TNF-α) concentrations decreased. MeHg was not associated with total Th2 cytokines but was associated with a decrease in IL-4 and IL-10. MeHg was positively associated with TARC and VEGF-D and negatively associated with CRP. There was a significant interaction between MeHg and the n-6:n-3 ratio, with MeHg associated with a larger decrease in Th1:Th2 at higher n-6:n-3 PUFA ratios. The n-3 PUFA were associated with lower CRP, IL-4 and higher IFN-γ. The n-6 PUFA were associated with higher IL-1β, IL-2, TNF-α, IL-4, IL-10, CRP and IL-6.

CONCLUSION

Maternal MeHg was associated with markers of immune function at 28 weeks' gestation. A significant interaction between MeHg and the n-6:n-3 ratio on the Th1:Th2 ratio suggests that the n-3 PUFA may mitigate any immunosuppressive associations of MeHg. The n-3 and n-6 PUFA were associated with suppressive and stimulatory immune responses, respectively. Overall, the associations were of small magnitude, and further research is required to determine the clinical significance.

Maternal obesity is not associated with placental lipid accumulation in women with high omega-3 fatty acid levels

INTRODUCTION

Placentas of obese women have higher lipid content compared to lean women. We have previously shown that supplementation of overweight and obese women with omega-3 fatty acids decreases placental esterification pathways and total lipid content in a mid-western population (Ohio). We hypothesized that placental lipid accumulation and inflammation would be similar between lean and obese women living in a region of high omega-3 intake, such as Hawaii.

METHODS

Fifty-five healthy, normal glucose tolerant women from Honolulu Hawaii, dichotomized based on pre-pregnancy BMI into lean (BMI <25 kg/m2, n = 29) and obese (BMI >30 kg/m2, n = 26), were recruited at scheduled term cesarean delivery. Maternal plasma DHA levels were analyzed by mass spectrometry. Expression of key genes involved in fatty acid oxidation and esterification were measured in placental tissue using qPCR. Total lipids were extracted from placental tissue via the Folch method. TNF-α concentration was measured by enzyme-linked immunosorbent assay in placental lysates.

RESULTS

DHA levels were higher in lean women compared to obese women (P = 0.02). However, DHA levels in obese women in Hawaii were eight times higher compared to obese Ohioan women (P=<0.0001). Placental lipid content and expression of key genes involved in fatty acid oxidation and esterification were similar (P > 0.05) between lean and obese women in Hawaii. Furthermore, TNF-α placental lysates were not different between lean and obese women.

CONCLUSIONS

Though obese women in Hawaii have lower DHA levels compared to their lean counterparts, these levels remain over eight times as high as obese Ohioan women. These relatively high plasma omega-3 levels in obese women in Hawaii may suppress placental lipid esterification/storage and inflammation to the same levels of lean women, as seen previously in vitro.

Alterations in placental long chain polyunsaturated fatty acid metabolism in human intrauterine growth restriction

Fatty acids (FA) are critical for fetal brain development and are transferred across the placenta by membrane-bound FA transport proteins (FATP), translocases (FAT/CD36), and cytosolic binding proteins (FABP). The cytosolic protein perilipin-2 aids in neutral lipid storage within lipid droplets. Decreased placental nutrient transport is believed to contribute to intrauterine growth restriction (IUGR); however, IUGR placental lipid transport and metabolism are poorly understood. We hypothesized that protein expression of FATPs, FABPs, and perilipin-2 in human placenta is decreased and placental lipid content and incorporation into lipid classes are reduced in IUGR. Placental tissue of idiopathic IUGR (n=25) and gestational age-matched, appropriately grown for gestational age (AGA) fetuses (n=19) was collected. We determined protein expression of FABP4 and perilipin-2 in placental homogenate and FATPs (2, 4, 6, CD36) in syncytiotrophoblast microvillous plasma membrane (MVM) by Western blot. Lipid droplet area (Oil Red O stain) and cellular FA content (GC/MS) were measured in chorionic villous tissue. MVM expression of FATP6 and CD36 was significantly increased in IUGR. The concentrations of seven n-6 and n-3 species long chain polyunsaturated FAs (LCPUFA) were significantly increased in the triglyceride fraction in IUGR vs AGA placenta. In summary, MVM FATP6 and CD36 protein expression is increased and LCPUFA are preferentially routed toward cellular storage in TG in the IUGR placenta, possibly to protect against oxidative stress associated with cellular FA accumulation. We speculate that these changes may be caused by impaired efflux of FA across the fetal-facing syncytiotrophoblast basal plasma membrane in IUGR placenta.

Placental fatty acid transfer

PURPOSE OF REVIEW

This review outlines recent advances in placental lipid transport in relation to maternal metabolic status and pregnancy outcome. A particular focus of this review will be on the way these findings may influence our understanding of placental transfer of the essential fatty acid docosahexaenoic acid (DHA) which is crucial for fetal neurodevelopment and of lipid transfer as a predisposing factor for childhood obesity.

RECENT FINDINGS

Placental metabolism may determine the quantity and composition of fatty acids delivered to the fetus. Maternal factors, such as obesity, appear to regulate placental lipid metabolism and may influence fatty acids delivery to the fetus. Although the role of placental metabolism is now recognized, new evidence also suggests important roles for nontraditional fatty acid transporters such as Mfsd2a which facilitates transfer of DHA.

SUMMARY

Placental lipid metabolism is likely to be a determinant of placental transfer of fatty acids to the fetus. Maternal conditions, such as obesity, have now been shown to regulate placental lipid metabolism and thus may influence fatty acid transfer and fetal development. However, it is not yet clear how regulation of placental lipid metabolism affects fatty acid delivery to the fetus and its long-term health.

Omega-3 Long-Chain Polyunsaturated Fatty Acids and Preeclampsia: Trials Say "No," but Is It the Final Word?

Preeclampsia is a dangerous disorder of pregnancy, defined as hypertension with proteinuria. Its nature remains elusive, and measures of prevention and treatment are limited. Observational studies have suggested that preeclampsia is associated with low intake of omega-3 long-chain polyunsaturated fatty acids (LCPUFA). In recent decades, researchers studied LCPUFA supplementation as a measure to prevent preeclampsia. Most of these trials and later systematic reviews yielded negative results. However, these trials had several important limitations associated with heterogeneity and other issues. Recent research suggests that preeclampsia trials should take into consideration the gender of the fetus (and thus sexual dimorphism of placenta), the positive effect of smoking on preeclampsia prevalence, and the possibility that high doses of LCPUFA mid-term or later may promote the disorder instead of keeping it at bay. In this review, we discuss these issues and future prospects for LCPUFA in preeclampsia research.

Omega-3 Consumption During Pregnancy to Support Optimal Outcomes

Long-chain omega-3 polyunsaturated fatty acids (n-3 LCPUFA), including docosahexaenoic acid, are components of cellular membranes that affect biological functioning. Most pregnant women consume inadequate amounts of n-3 LCPUFA and inadequately convert linolenic acid into docosahexaenoic acid. The purpose of this article is to educate nursing professionals on the importance of n-3 LCPUFA consumption during pregnancy and highlight the critical role of nursing professionals in supporting optimal consumption for improved metabolic, antioxidant, and anti-inflammatory potential.

Resolution of Cochlear Inflammation: Novel Target for Preventing or Ameliorating Drug-, Noise- and Age-related Hearing Loss

A significant number of studies support the idea that inflammatory responses are intimately associated with drug-, noise- and age-related hearing loss (DRHL, NRHL and ARHL). Consequently, several clinical strategies aimed at reducing auditory dysfunction by preventing inflammation are currently under intense scrutiny. Inflammation, however, is a normal adaptive response aimed at restoring tissue functionality and homeostasis after infection, tissue injury and even stress under sterile conditions, and suppressing it could have unintended negative consequences. Therefore, an appropriate approach to prevent or ameliorate DRHL, NRHL and ARHL should involve improving the resolution of the inflammatory process in the cochlea rather than inhibiting this phenomenon. The resolution of inflammation is not a passive response but rather an active, highly controlled and coordinated process. Inflammation by itself produces specialized pro-resolving mediators with critical functions, including essential fatty acid derivatives (lipoxins, resolvins, protectins and maresins), proteins and peptides such as annexin A1 and galectins, purines (adenosine), gaseous mediators (NO, H₂S and CO), as well as neuromodulators like acetylcholine and netrin-1. In this review article, we describe recent advances in the understanding of the resolution phase of inflammation and highlight therapeutic strategies that might be useful in preventing inflammation-induced cochlear damage. In particular, we emphasize beneficial approaches that have been tested in pre-clinical models of inflammatory responses induced by recognized ototoxic drugs such as cisplatin and aminoglycoside antibiotics. Since these studies suggest that improving the resolution process could be useful for the prevention of inflammation-associated diseases in humans, we discuss the potential application of similar strategies to prevent or mitigate DRHL, NRHL and ARHL.