Maternal BMI and gestational diabetes alter placental lipid transporters and fatty acid composition

Placental Epigenome Impacts Fetal Development: Effects of Maternal Nutrients and Gut Microbiota

Evidence is emerging on the role of maternal diet, gut microbiota, and other lifestyle factors in establishing lifelong health and disease, which are determined by transgenerationally inherited epigenetic modifications. Understanding epigenetic mechanisms may help identify novel biomarkers for gestation-related exposure, burden, or disease risk. Such biomarkers are essential for developing tools for the early detection of risk factors and exposure levels. It is necessary to establish an exposure threshold due to nutrient deficiencies or other environmental factors that can result in clinically relevant epigenetic alterations that modulate disease risks in the fetus. This narrative review summarizes the latest updates on the roles of maternal nutrients (n-3 fatty acids, polyphenols, vitamins) and gut microbiota on the placental epigenome and its impacts on fetal brain development. This review unravels the potential roles of the functional epigenome for targeted intervention to ensure optimal fetal brain development and its performance in later life.

Maternal obesity and placental function: impaired maternal-fetal axis

The prevalence of maternal obesity rapidly increases, which represents a major public health concern worldwide. Maternal obesity is characteristic by metabolic dysfunction and chronic inflammation. It is associated with health problems in both mother and offspring. Increasing evidence indicates that the placenta is an axis connecting maternal obesity with poor outcomes in the offspring. In this brief review, we have summarized the current data regarding deregulated placental function in maternal obesity. The data show that maternal obesity induces numerous placental defects, including lipid and glucose metabolism, stress response, inflammation, immune regulation and epigenetics. These placental defects affect each other and result in a stressful intrauterine environment, which transduces and mediates the adverse effects of maternal obesity to the fetus. Further investigations are required to explore the exact molecular alterations in the placenta in maternal obesity, which may pave the way to develop specific interventions for preventing epigenetic and metabolic programming in the fetus.

Early-life exposure to gestational diabetes mellitus predisposes offspring to pediatric nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has emerged as the prevailing chronic liver disease in the pediatric population due to the global obesity pandemic. Evidence shows that prenatal and postnatal exposure to maternal abnormalities leads to a higher risk of pediatric NAFLD through persistent alterations in developmental programming. Gestational diabetes mellitus (GDM) is a hyperglycemic syndrome which has become the most prevalent complication in pregnant women. An increasing number of both epidemiologic investigations and animal model studies have validated adverse and long-term outcomes in offspring following GDM exposure in utero. Similarly, GDM is considered a crucial risk factor for pediatric NAFLD. This review aimed to summarize currently published studies concerning the inductive roles of GDM in offspring NAFLD development during childhood and adolescence. Dysregulations in hepatic lipid metabolism and gut microbiota in offspring, as well as dysfunctions in the placenta are potential factors in the pathogenesis of GDM-associated pediatric NAFLD. In addition, potentially effective interventions for GDM-associated offspring NAFLD are also discussed in this review. However, most of these therapeutic approaches still require further clinical research for validation.

Pregnancy-related maternal physiological adaptations and fetal chemical exposure

Prenatal life represents a susceptible window of development during which chemical exposures can permanently alter fetal development, leading to an increased likelihood of disease later in life. Therefore, it is essential to assess exposure in the fetus. However, direct assessment in human fetuses is challenging, so most research measures maternal exposure. Pregnancy induces a range of significant physiological changes in women that may affect chemical metabolism and responses. Moreover, placental function, fetal sex, and pregnancy complications may further modify these exposures. The purpose of this narrative review is to give an overview of major pregnancy-related physiological changes, including placental function and impacts of pregnancy complications, to summarize existing studies assessing chemical exposure in human fetal organs, and to discuss possible interactions between physiological changes and exposures. Our review reveals major knowledge gaps in factors affecting fetal chemical exposure, highlighting the need to develop more sophisticated tools for chemical health risk assessment in fetuses.

Adverse effects of gestational ω-3 and ω-6 polyunsaturated fatty acid imbalance on the programming of fetal brain development

Obesity is a key medical challenge of our time. The increasing number of children born to overweight or obese women is alarming. During pregnancy, the circulation of the mother and her fetus interact to maintain the uninterrupted availability of essential nutrients for fetal organ development. In doing so, the mother's dietary preference determines the amount and composition of nutrients reaching the fetus. In particular, the availability of polyunsaturated fatty acids (PUFAs), chiefly their ω-3 and ω-6 subclasses, can change when pregnant women choose a specific diet. Here, we provide a succinct overview of PUFA biochemistry, including exchange routes between ω-3 and ω-6 PUFAs, the phenotypes, and probable neurodevelopmental disease associations of offspring born to mothers consuming specific PUFAs, and their mechanistic study in experimental models to typify signaling pathways, transcriptional, and epigenetic mechanisms by which PUFAs can imprint long-lasting modifications to brain structure and function. We emphasize that the ratio, rather than the amount of individual ω-3 or ω-6 PUFAs, might underpin physiologically correct cellular differentiation programs, be these for neurons or glia, during pregnancy. Thereupon, the PUFA-driven programming of the brain is contextualized for childhood obesity, metabolic, and endocrine illnesses.

An Integrated Multi-OMICS Approach Highlights Elevated Non-Esterified Fatty Acids Impact BeWo Trophoblast Metabolism and Lipid Processing

Maternal obesity and gestational diabetes mellitus (GDM) are linked with impaired placental function and early onset of non-communicable cardiometabolic diseases in offspring. Previous studies have highlighted that the dietary non-esterified fatty acids (NEFAs) palmitate (PA) and oleate (OA), key dietary metabolites associated with maternal obesity and GDM, are potential modulators of placental lipid processing. Using the BeWo cell line model, the current study integrated transcriptomic (mRNA microarray), metabolomic, and lipidomic readouts to characterize the underlying impacts of exogenous PA and OA on placental villous trophoblast cell metabolism. Targeted gas chromatography and thin-layer chromatography highlighted that saturated and monounsaturated NEFAs differentially impact BeWo cell lipid profiles. Furthermore, cellular lipid profiles differed when exposed to single and multiple NEFA species. Additional multi-omic analyses suggested that PA exposure is associated with enrichment in β-oxidation pathways, while OA exposure is associated with enrichment in anti-inflammatory and antioxidant pathways. Overall, this study further demonstrated that dietary PA and OA are important regulators of placental lipid metabolism. Encouraging appropriate dietary advice and implementing dietary interventions to maintain appropriate placental function by limiting excessive exposure to saturated NEFAs remain crucial in managing at-risk obese and GDM pregnancies.

Expression of nutrient transporters in placentas affected by gestational diabetes: role of leptin

Gestational diabetes mellitus (GDM) is the most frequent pathophysiological state of pregnancy, which in many cases produces fetuses with macrosomia, requiring increased nutrient transport in the placenta. Recent studies by our group have demonstrated that leptin is a key hormone in placental physiology, and its expression is increased in placentas affected by GDM. However, the effect of leptin on placental nutrient transport, such as transport of glucose, amino acids, and lipids, is not fully understood. Thus, we aimed to review literature on the leptin effect involved in placental nutrient transport as well as activated leptin signaling pathways involved in the expression of placental transporters, which may contribute to an increase in placental nutrient transport in human pregnancies complicated by GDM. Leptin appears to be a relevant key hormone that regulates placental transport, and this regulation is altered in pathophysiological conditions such as gestational diabetes. Adaptations in the placental capacity to transport glucose, amino acids, and lipids may underlie both under- or overgrowth of the fetus when maternal nutrient and hormone levels are altered due to changes in maternal nutrition or metabolic disease. Implementing new strategies to modulate placental transport may improve maternal health and prove effective in normalizing fetal growth in cases of intrauterine growth restriction and fetal overgrowth. However, further studies are needed to confirm this hypothesis.

DHA supplementation and pregnancy complications

Docosahexaenoic acid (DHA) supplementation is recommended for women during pregnancy because of its neurological, visual, and cognitive effects. Previous studies have suggested that DHA supplementation during pregnancy may prevent and treat certain pregnancy complications. However, there are contradictions in the current related studies, and the specific mechanism by which DHA acts remains unclear. This review summarizes the research on the relationship between DHA intake during pregnancy and preeclampsia, gestational diabetes mellitus, preterm birth, intrauterine growth restriction, and postpartum depression. Furthermore, we explore the impact of DHA intake during pregnancy on the prediction, prevention, and treatment of pregnancy complications as well as its impact on offspring neurodevelopment. Our results suggest that there is limited and controversial evidence for the protective effect of DHA intake on pregnancy complications, with the exception of preterm birth and gestational diabetes mellitus. However, additional DHA supplementation may improve long-term neurodevelopmental outcomes in the offspring of women with pregnancy complications.

Placental AA/EPA Ratio Is Associated with Obesity Risk Parameters in the Offspring at 6 Years of Age

During pregnancy, maternal polyunsaturated fatty acids (PUFA) are transferred to the fetus through the placenta by specific FA transporters (FATP). A higher perinatal exposure to n-6 over n-3 PUFA could be linked to excess fat mass and obesity development later in life. In this context, we aimed to assess the associations between long chain PUFAs (LC-PUFAs) (n-6, n-3, and n-6/n-3 ratios) measured in the placenta at term birth with obesity-related parameters in the offspring at 6 years of age and assess whether these associations are dependent on the placental relative expression of fatty acid transporters. As results, the PUFAn-6/PUFAn-3 ratio was 4/1, which scaled up to 15/1 when considering only the arachidonic acid/eicosapentaenoic acid ratio (AA/EPA ratio). Positive associations between the AA/EPA ratio and offspring's obesity risk parameters were found with weight-SDS, BMI-SDS, percent fat mass-SDS, visceral fat, and HOMA-IR (r from 0.204 to 0.375; all p < 0.05). These associations were more noticeable in those subjects with higher expression of fatty acid transporters. Therefore, in conclusion, a higher placental AA/EPA ratio is positively associated with offspring's visceral adiposity and obesity risk parameters, which become more apparent in subjects with higher expressions of placental FATPs. Our results support the potential role of n-6 and n-3 LC-PUFA in the fetal programming of obesity risk in childhood. For the present study, 113 healthy pregnant women were recruited during the first trimester of pregnancy and their offspring were followed up at 6 years of age. The fatty acid profiles and the expression of fatty acid transporters (FATP1 and FATP4) were analyzed from placental samples at birth. Associations between LC-PUFA (n-6, n-3, and n-6/n-3 ratios) and obesity risk parameters (weight, body mass index (BMI), percent fat mass, visceral fat, and homeostatic model assessment of insulin resistance (HOMA-IR)) in the offspring at 6 years of age were examined.

Human Placental Adaptive Changes in Response to Maternal Obesity: Sex Specificities

Maternal obesity is increasingly prevalent and is associated with elevated morbidity and mortality rates in both mothers and children. At the interface between the mother and the fetus, the placenta mediates the impact of the maternal environment on fetal development. Most of the literature presents data on the effects of maternal obesity on placental functions and does not exclude potentially confounding factors such as metabolic diseases (e.g., gestational diabetes). In this context, the focus of this review mainly lies on the impact of maternal obesity (in the absence of gestational diabetes) on (i) endocrine function, (ii) morphological characteristics, (iii) nutrient exchanges and metabolism, (iv) inflammatory/immune status, (v) oxidative stress, and (vi) transcriptome. Moreover, some of those placental changes in response to maternal obesity could be supported by fetal sex. A better understanding of sex-specific placental responses to maternal obesity seems to be crucial for improving pregnancy outcomes and the health of mothers and children.

Development and validation of risk prediction models for large for gestational age infants using logistic regression and two machine learning algorithms

BACKGROUND

Large for gestational age (LGA) is one of the adverse outcomes during pregnancy that endangers the life and health of mothers and offspring. We aimed to establish prediction models for LGA at late pregnancy.

METHODS

Data were obtained from an established Chinese pregnant women cohort of 1285 pregnant women. LGA was diagnosed as >90th percentile of birth weight distribution of Chinese corresponding to gestational age of the same-sex newborns. Women with gestational diabetes mellitus (GDM) were classified into three subtypes according to the indexes of insulin sensitivity and insulin secretion. Models were established by logistic regression and decision tree/random forest algorithms, and validated by the data.

RESULTS

A total of 139 newborns were diagnosed as LGA after birth. The area under the curve (AUC) for the training set is 0.760 (95% confidence interval [CI] 0.706-0.815), and 0.748 (95% CI 0.659-0.837) for the internal validation set of the logistic regression model, which consisted of eight commonly used clinical indicators (including lipid profile) and GDM subtypes. For the prediction models established by the two machine learning algorithms, which included all the variables, the training set and the internal validation set had AUCs of 0.813 (95% CI 0.786-0.839) and 0.779 (95% CI 0.735-0.824) for the decision tree model, and 0.854 (95% CI 0.831-0.877) and 0.808 (95% CI 0.766-0.850) for the random forest model.

CONCLUSION

We established and validated three LGA risk prediction models to screen out the pregnant women with high risk of LGA at the early stage of the third trimester, which showed good prediction power and could guide early prevention strategies.

Placental adaptations supporting fetal growth during normal and adverse gestational environments

NEW FINDINGS

What is the topic of this review? How the placenta, which transports nutrients and oxygen to the fetus, may alter its support of fetal growth developmentally and with adverse gestational conditions. What advances does it highlight? Placental formation and function alter with the needs of the fetus for substrates for growth during normal gestation and when there is enhanced competition for substrates in species with multiple gestations or adverse gestational environments, and this is mediated by imprinted genes, signalling pathways, mitochondria and fetal sexomes.

ABSTRACT

The placenta is vital for mammalian development and a key determinant of life-long health. It is the interface between the mother and fetus and is responsible for transporting the nutrients and oxygen a fetus needs to develop and grow. Alterations in placental formation and function, therefore, have consequences for fetal growth and birthweight, which in turn determine perinatal survival and risk of non-communicable diseases for the offspring in later postnatal life. However, the placenta is not a static organ. As this review summarizes, research from multiple species has demonstrated that placental formation and function alter developmentally to the needs of the fetus for substrates for growth during normal gestation, as well as when there is greater competition for substrates in polytocous species and monotocous species with multiple gestations. The placenta also adapts in response to the gestational environment, integrating information about the ability of the mother to provide nutrients and oxygen with the needs of the fetus in that prevailing environment. In particular, placental structure (e.g. vascularity, surface area, blood flow, diffusion distance) and transport capacity (e.g. nutrient transporter levels and activity) respond to suboptimal gestational environments, namely malnutrition, obesity, hypoxia and maternal ageing. Mechanisms mediating developmentally and environmentally induced homeostatic responses of the placenta that help support normal fetal growth include imprinted genes, signalling pathways, subcellular constituents and fetal sexomes. Identification of these placental strategies may inform the development of therapies for complicated human pregnancies and advance understanding of the pathways underlying poor fetal outcomes and their consequences for health and disease risk.

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.

Increasing maternal age predicts placental protein expression critical for fetal serotonin metabolism: Potential implications for neurodevelopmental research

High fetal exposure to serotonin and increasing maternal age both contribute to the risk for neurodevelopmental disorders. While identifying covariates for a study of placental protein expression, we found a significant negative correlation between maternal age and the expression of monoamine oxidase A (MAOA), and a significant positive correlation between maternal age and the expression of the serotonin transporter SERT. MAOA and SERT play key roles in placental serotonin metabolism relevant to fetal neurodevelopment. These preliminary findings suggest that the effect of increasing maternal age on neurodevelopmental risk may be mediated in part by changes in placental protein expression relevant to fetal serotonin metabolism.

Maternal Obesity and Gut Microbiota Are Associated with Fetal Brain Development

Obesity in pregnancy induces metabolic syndrome, low-grade inflammation, altered endocrine factors, placental function, and the maternal gut microbiome. All these factors impact fetal growth and development, including brain development. The lipid metabolic transporters of the maternal-fetal-placental unit are dysregulated in obesity. Consequently, the transport of essential long-chain PUFAs for fetal brain development is disturbed. The mother’s gut microbiota is vital in maintaining postnatal energy homeostasis and maternal-fetal immune competence. Obesity during pregnancy changes the gut microbiota, affecting fetal brain development. Obesity in pregnancy can induce placental and intrauterine inflammation and thus influence the neurodevelopmental outcomes of the offspring. Several epidemiological studies observed an association between maternal obesity and adverse neurodevelopment. This review discusses the effects of maternal obesity and gut microbiota on fetal neurodevelopment outcomes. In addition, the possible mechanisms of the impacts of obesity and gut microbiota on fetal brain development are discussed.

Maternal obesity: new placental paradigms unfolded

The prevalence of maternal obesity is increasing at an alarming rate, and is providing a major challenge for obstetric practice. Adverse effects on maternal and fetal health are mediated by complex interactions between metabolic, inflammatory, and oxidative stress signaling in the placenta. Endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) are common downstream pathways of cell stress, and there is evidence that this conserved homeostatic response may be a key mediator in the pathogenesis of placental dysfunction. We summarize the current literature on the placental cellular and molecular changes that occur in obese women. A special focus is cast onto placental ER stress in obese pregnancy, which may provide a novel link for future investigation.

Association of Prepregnancy Obesity and Remodeled Maternal-Fetal Plasma Fatty Acid Profiles

Background

Fatty acids, especially polyunsaturated fatty acid (PUFA), are found abundantly in the brain and are fundamental for a fetus's growth. The fatty acid profiles of mothers and fetuses may be affected by maternal prepregnancy body mass index (pre-BMI), thus affecting fetal growth and development.

Methods

A total of 103 mother-fetus pairs were divided into overweight/obese (OW, n = 26), normal weight (NW, n = 60), and underweight (UW, n = 17) groups according to pre-BMI. Fatty acid profiles in maternal and umbilical cord plasma were analyzed by gas chromatography.

Results

The infant birth BMI z-score of the OW group was higher than that of the NW and UW groups (p < 0.05). The OW mothers had significantly higher plasma n-6 PUFA and n-6/n-3, but lower docosahexaenoic acid (DHA) and n-3 PUFA (p < 0.05). In cord plasma, the proportions of DHA and n-3 PUFA were lower in the OW group (p < 0.05), whereas the n-6/n-3 ratio was higher in the OW group (p < 0.05). The pre-BMI was negatively correlated with cord plasma DHA in all subjects (r = −0.303, p = 0.002), and the same negative correlation can be observed in the OW group (r = −0.561, p = 0.004), but not in the NW and UW groups (p > 0.05). The pre-BMI was positively correlated with cord plasma n-6/n-3 in all subjects (r = 0.325, p = 0.001), and the same positive correlation can be found in the OW group (r = 0.558, p = 0.004), but not in NW and UW groups (p > 0.05).

Conclusions

Maternal pre-BMI was associated with the maternal-fetal plasma fatty acid profiles, whereas the adverse fatty acid profiles are more noticeable in the prepregnancy OW mothers.

Lipids and Long Chain Polyunsaturated Fatty Acids in Preterm Infants

Fatty acids are critical bioactives for fetal and neonatal development. Premature delivery and current nutritional strategies pose several challenges in restoring fatty acid balance in the preterm infant. The impact on fatty acid balance and outcomes using lipid emulsions, enteral nutrition, and enteral supplements are reviewed, including a summary of the most recent large clinical trials of enteral fatty acid supplementation for the preterm infant. Research gaps remain in successfully implementing nutritional strategies to optimize fatty acid status in preterm infants.

Placental Nutrient Transporters and Maternal Fatty Acids in SGA, AGA, and LGA Newborns From Mothers With and Without Obesity

Adverse environmental factors in early life result in fetal metabolic programming and increased risk of adult diseases. Birth weight is an indirect marker of the intrauterine environment, modulated by nutrient availability and placental transport capacity. However, studies of placental transporters in idiopathic birth weight alterations and in maternal obesity in relation to neonatal metabolic outcomes are scarce. We aimed to analyze the placental nutrient transporter protein expression in small (SGA, n = 14), adequate (AGA, n = 18), and large (LGA n = 10) gestational age term for newborns from healthy or obese mothers (LGA-OB, n = 9) and their association with maternal fatty acids, metabolic status, placental triglycerides, and neonatal outcomes. The transporter expression was determined by Western blot. The fatty acid profile was evaluated by gas chromatography, and placental triglycerides were quantified by an enzymatic colorimetric method. GLUT1 was higher in LGA and lower in SGA and positively correlated with maternal HbA1c and placental weight (PW). SNAT2 was lower in SGA, while SNAT4 was lower in LGA-OB. FATP1 was lower in SGA and higher in LGA. SNAT4 correlated negatively and FATP1 correlated positively with the PW and birth anthropometry (BA). Placental triglycerides were higher in LGA and LGA-OB and correlated with pregestational BMI, maternal insulin, and BA. Maternal docosahexaenoic acid (DHA) was higher in SGA, specifically in male placentas, correlating negatively with maternal triglycerides, PW, cord glucose, and abdominal perimeter. Palmitic acid (PA) correlated positively with FATP4 and cord insulin, linoleic acid correlated negatively with PA and maternal cholesterol, and arachidonic acid correlated inversely with maternal TG and directly with FATP4. Our study highlights the importance of placental programming in birth weight both in healthy and obese pregnancies.

Ontogeny of circulating lipid metabolism in pregnancy and early childhood: a longitudinal population study

Background: There is mounting evidence that in utero and early life exposures may predispose an individual to metabolic disorders in later life; and dysregulation of lipid metabolism is critical in such outcomes. However, there is limited knowledge about lipid metabolism and factors causing lipid dysregulation in early life that could result in adverse health outcomes in later life. We studied the effect of antenatal factors such as gestational age, birth weight and mode of birth on lipid metabolism at birth; changes in the circulating lipidome in the first four years of life and the effect of breastfeeding in the first year of life. From this study, we aim to generate a framework for deeper understanding into factors effecting lipid metabolism in early life, to provide early interventions for those at risk of developing metabolic disorders including cardiovascular diseases.

Methods and findings: We performed comprehensive lipid profiling of 1074 mother-child dyads in the Barwon Infant Study (BIS), a population based pre-birth cohort and measured 776 distinct lipid species across 42 lipid classes using ultra high-performance liquid chromatography (UHPLC). We measured lipids in 1032 maternal serum samples at 28 weeks' gestation, 893 cord serum samples at birth, 793, 735, and 511 plasma samples at six, twelve months, and four years, respectively. The lipidome differed between mother and newborn and changed markedly with increasing child's age. Cord serum was enriched with long chain poly-unsaturated fatty acids (LC-PUFAs), and corresponding cholesteryl esters relative to the maternal serum. Alkenylphosphatidylethanolamine species containing LC-PUFAs increased with child's age, whereas the corresponding lysophospholipids and triglycerides decreased. We performed regression analyses to investigate the associations of cord serum lipid species with antenatal factors: gestational age, birth weight, mode of birth and duration of labor. Majority of the cord serum lipids were strongly associated with gestational age and birth weight, with most lipids showing opposing associations. Each mode of birth showed an independent association with cord serum lipids. Breastfeeding had a significant impact on the plasma lipidome in the first year of life, with upto 17-fold increases in a few species of alkyldiaclylglycerols at 6 months of age.

Conclusions: This study sheds light on lipid metabolism in infancy and early childhood and provide a framework to define the relationship between lipid metabolism and health outcomes in early childhood.

Funding Statement: This work was supported by the A*STAR-NHMRC joint call funding (1711624031).

Placental lipid transport and content in response to maternal overweight and gestational diabetes mellitus in human term placenta

BACKGROUND AND AIMS

Placental lipid transport is altered in women with high prepregnancy body mass index (pre-BMI) or gestational diabetes (GDM), which consequently affects foetal growth. However, the interaction of maternal overweight (OW) and GDM on placental lipid metabolism and possible adaptations are less studied. We aimed to examine whether maternal OW or GDM is the main factor disrupting placental lipid processing in human term placenta.

METHODS AND RESULTS

A total of 152 lean (18.5 ≤ pre-BMI ≤ 23.9 kg/m²) and OW (24 ≤ pre-BMI ≤ 27.9 kg/m²) pregnant women with or without GDM with a scheduled delivery by caesarean section were recruited. Maternal venous blood samples were used to measure metabolic parameters during pregnancy. Term placentas and cord blood were collected at delivery to determine placental lipid metabolism and foetal circulating lipid levels. Maternal OW significantly increased the placental mRNA expression of genes involved in lipid metabolism (FAT/CD36, FATP1, FATP4, FATP6, and PPAR-α), elevated placental lipid content (triglyceride, cholesterol), enhanced placental mTORC1-rpS6 and ERK1/2 signalling, increased cord blood insulin levels and birth weight. Neonatal birth weight was positively correlated with maternal pre-BMI, placental ERK1/2 signalling and cord blood insulin. There was an interaction between OW and GDM in regulating key placental fuel transport and storage gene expression (LPL, FATP6, FABP7, PPAR-α, PPAR-β, PPAR-γ, IR-β, GLUT1, SNAT2, SNAT4, and LAT1).

CONCLUSION

Maternal OW mainly affects placental lipid metabolism, which may contribute to foetal overgrowth and may impact long-term offspring health. GDM plays a less significant role in affecting placental lipid transfer and other mechanisms may be involved.

Lipid endocannabinoids in energy metabolism, stress and developmental programming

The endocannabinoid system (ECS) regulates brain development and function, energy metabolism and stress in a sex-, age- and tissue-dependent manner. The ECS comprises mainly the bioactive lipid ligands anandamide (AEA) and 2-aracdonoylglycerol (2-AG), cannabinoid receptors 1 and 2 (CB1 and CB2), and several metabolizing enzymes. The endocannabinoid tonus is increased in obesity, stimulating food intake and a preference for fat, reward, and lipid accumulation in peripheral tissues, as well as favoring a positive energy balance. Energy balance and stress responses share adaptive mechanisms regulated by the ECS that seem to underlie the complex relationship between feeding and emotional behavior. The ECS is also a key regulator of development. Environmental insults (diet, toxicants, and stress) in critical periods of developmental plasticity, such as gestation, lactation and adolescence, alter the ECS and may predispose individuals to the development of chronic diseases and behavioral changes in the long term. This review is focused on the ECS and the developmental origins of health and disease (DOHaD).

Comparative Lipidomic Study of Human Placenta from Women with or without Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is always accompanied by lipid disorders. Placenta serves as a center for lipid synthesis and transport and plays a critical role in establishing of GDM. Thus,...

Prenatal particulate matter exposure and mitochondrial mutational load at the maternal-fetal interface: Effect modification by genetic ancestry

Prenatal ambient particulate matter (PM2.5) exposure impacts infant development and alters placental mitochondrial DNA abundance. We investigated whether the timing of PM2.5 exposure predicts placental mitochondrial mutational load using NextGen sequencing in 283 multi-ethnic mother-infant dyads. We observed increased PM2.5exposure, particularly during mid- to late-pregnancy and among genes coding for NADH dehydrogenase and subunits of ATP synthase, was associated with a greater amount of nonsynonymous mutations. The strongest associations were observed for participants of African ancestry. Further work is needed to tease out the role of mitochondrial genetics and its impact on offspring development and emerging disease disparities.

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.

Increased Fetal Cardiovascular Disease Risk: Potential Synergy Between Gestational Diabetes Mellitus and Maternal Hypercholesterolemia

Cardiovascular diseases (CVD) remain a major cause of death worldwide. Evidence suggests that the risk for CVD can increase at the fetal stages due to maternal metabolic diseases, such as gestational diabetes mellitus (GDM) and maternal supraphysiological hypercholesterolemia (MSPH). GDM is a hyperglycemic, inflammatory, and insulin-resistant state that increases plasma levels of free fatty acids and triglycerides, impairs endothelial vascular tone regulation, and due to the increased nutrient transport, exposes the fetus to the altered metabolic conditions of the mother. MSPH involves increased levels of cholesterol (mainly as low-density lipoprotein cholesterol) which also causes endothelial dysfunction and alters nutrient transport to the fetus. Despite that an association has already been established between MSPH and increased CVD risk, however, little is known about the cellular processes underlying this relationship. Our knowledge is further obscured when the simultaneous presentation of MSPH and GDM takes place. In this context, GDM and MSPH may substantially increase fetal CVD risk due to synergistic impairment of placental nutrient transport and endothelial dysfunction. More studies on the separate and/or cumulative role of both processes are warranted to suggest specific treatment options.

Decreased Fatty Acid Transporter FABP1 and Increased Isoprostanes and Neuroprostanes in the Human Term Placenta: Implications for Inflammation and Birth Weight in Maternal Pre-Gestational Obesity

The rise in prevalence of obesity in women of reproductive age in developed and developing countries might propagate intergenerational cycles of detrimental effects on metabolic health. Placental lipid metabolism is disrupted by maternal obesity, which possibly affects the life-long health of the offspring. Here, we investigated placental lipid metabolism in women with pre-gestational obesity as a sole pregnancy complication and compared it to placental responses of lean women. Open profile and targeted lipidomics were used to assess placental lipids and oxidised products of docosahexaenoic (DHA) and arachidonic acid (AA), respectively, neuroprostanes and isoprostanes. Despite no overall signs of lipid accumulation, DHA and AA levels in placentas from obese women were, respectively, 2.2 and 2.5 times higher than those from lean women. Additionally, a 2-fold increase in DHA-derived neuroprostanes and a 1.7-fold increase in AA-derived isoprostanes were seen in the obese group. These changes correlated with a 70% decrease in placental FABP1 protein. Multivariate analyses suggested that neuroprostanes and isoprostanes are associated with maternal and placental inflammation and with birth weight. These results might shed light on the molecular mechanisms associated with altered placental fatty acid metabolism in maternal pre-gestational obesity, placing these oxidised fatty acids as novel mediators of placental function.

Placental 13C-DHA metabolism and relationship with maternal BMI, glycemia and birthweight

BACKGROUND

Fetal docosahexaenoic acid (DHA) supply relies on preferential transplacental transfer, which is regulated by placental DHA lipid metabolism. Maternal hyperglycemia and obesity associate with higher birthweight and fetal DHA insufficiency but the role of placental DHA metabolism is unclear.

METHODS

Explants from 17 term placenta were incubated with 13C-labeled DHA for 48 h, at 5 or 10 mmol/L glucose treatment, and the production of 17 individual newly synthesized 13C-DHA labeled lipids quantified by liquid chromatography mass spectrometry.

RESULTS

Maternal BMI positively associated with 13C-DHA-labeled diacylglycerols, triacylglycerols, lysophospholipids, phosphatidylcholine and phosphatidylethanolamine plasmalogens, while maternal fasting glycemia positively associated with five 13C-DHA triacylglycerols. In turn, 13C-DHA-labeled phospholipids and triacylglycerols positively associated with birthweight centile. In-vitro glucose treatment increased most 13C-DHA-lipids, but decreased 13C-DHA phosphatidylethanolamine plasmalogens. However, with increasing maternal BMI, the magnitude of the glucose treatment induced increase in 13C-DHA phosphatidylcholine and 13C-DHA lysophospholipids was curtailed, with further decline in 13C-DHA phosphatidylethanolamine plasmalogens. Conversely, with increasing birthweight centile glucose treatment induced increases in 13C-DHA triacylglycerols were exaggerated, while glucose treatment induced decreases in 13C-DHA phosphatidylethanolamine plasmalogens were diminished.

CONCLUSIONS

Maternal BMI and glycemia increased the production of different placental DHA lipids implying impact on different metabolic pathways. Glucose-induced elevation in placental DHA metabolism is moderated with higher maternal BMI. In turn, findings of associations between many DHA lipids with birthweight suggest that BMI and glycemia promote fetal growth partly through changes in placental DHA metabolism.

Gestational diabetes mellitus decreased umbilical cord blood polyunsaturated fatty acids: a meta-analysis of observational studies

BACKGROUND

Polyunsaturated fatty acid (PUFA) is important for the development of the fetal brain, and the retina. Gestational diabetes mellitus (GDM) may influence maternal and fetal fatty acid metabolism, in turn affecting fetal growth and development. In several studies, maternal and fetal PUFA metabolic differences have been reported between mothers with and without GDM, but not in other studies. Thus, the aim of this meta-analysis (registration number: CRD42020220448) was to compare levels of linoleic acid (LA), α-linolenic acid (ALA), arachidonic acid (AA), docosahexaenoic acid (DHA), and total n-3 and n-6 PUFA between mothers with and without GMD and their fetuses.

METHODS

We performed a meta-analysis of observational studies on maternal and fetal fatty acid metabolism, published until May 2021. In addition, we performed subgroup analysis depending on the analyzed tissues (plasma/serum, erythrocyte membrane, or placenta) and the expression modes of fatty acids (concentration or percentage).

RESULTS

We included 24 observational studies involving 4335 maternal datasets and 12 studies involving 1675 fetal datasets in the meta-analysis. Levels of AA, DHA, and n-6 and n-3 PUFA were lower in the cord blood of mothers with GDM than in controls (P  <  0.05). Compared to that in controls, in erythrocyte membranes, the percentages of AA, DHA, and n-6 and n-3 PUFA in total fatty acid were lower in mothers with GDM (P  <  0.05), but in plasma/serum, the percentages of AA, DHA, and n-6 PUFA in total fatty acid were higher in mothers with GDM (P  <  0.05).

CONCLUSIONS

GDM appears to influence the transfer of PUFAs from mothers to fetuses. The percentage of PUFAs in maternal plasma/serum was higher, and that in erythrocyte membranes was lower in mothers with GDM compared to those with normal glucose tolerance.

Adiponectin agonist treatment in diabetic pregnant rats

Gestational diabetes mellitus (GDM) reduces maternal adiponectin and docosahexaenoic acid (DHA) materno-fetal transfer, which may have negative consequences for the offspring. Our aim was to evaluate the effects of the administration of a novel adiponectin agonist (AdipoRon) to GDM rats on the long-term consequences in glycaemia and fatty acids (FA) profile in the offspring. Pregnant rats were randomized to three groups: GDM rats (GDM, n = 8), GDM rats treated with AdipoRon (GDM + ADI, n = 9), and control rats (n = 10). Diabetes was induced with streptozotocin (50 mg/kg) on day 12 of gestation. GDM+ADI received 50 mg/kg/day AdipoRon from day 14 until delivery. Glycaemia and FA profile were determined in mothers and adult offspring (12 weeks old). AdipoRon tended to reduce fasting glucose in diabetic mothers. Diabetic rats presented the foetus with intrauterine growth restriction and higher adiposity, which tried to be counteracted by AdipoRon. In the adult offspring, both GDM + ADI and control animals showed better glucose recovery after oral glucose overload with respect to GDM. DHA in offspring plasma was significantly reduced in both GDM and GDM + ADI compared to controls (P = 0.043). Nevertheless, n-6/n-3 polyunsaturated FA (PUFA) ratio improved in plasma of GDM + ADI adult offspring (GDM: 14.83 ± 0.85a%; GDM + ADI: 11.49 ± 0.58b%; control: 10.03 ± 1.22b%, P = 0.034). Inflammatory markers and oxidative stress were reduced in the adult offspring of AdipoRon-treated mothers. In conclusion, AdipoRon administration to pregnant diabetic rats improved glycaemia in the mothers and long-term glucose tolerance in the offspring. In addition, it tended to reduce excessive foetal fat accumulation and improved n-6/n-3 PUFA ratio significantly in offspring at the adult state.

Effect of type 2 diabetes mellitus on placental expression and activity of nutrient transporters and their association with birth weight and neonatal adiposity

AIMS

Infants born to women with Type 2 Diabetes Mellitus (T2DM) are at risk of being born large for gestational age due to excess fetal fat accretion. Placental nutrient transport determines fetal nutrient availability, impacting fetal growth. The aims of the study were to evaluate the effect of T2DM on placental insulin signaling, placental nutrient transporters and neonatal adiposity.

METHODS

Placentas were collected from BMI-matched normoglycemic controls (NGT, n = 9) and T2DM (n = 9) women. Syncytiotrophoblast microvillous (MVM) and basal (BM) plasma membranes were isolated. Expression of glucose (GLUT1, -4), fatty acid (FATP2, -4, -6, FAT/CD36), amino acid (SNAT1, -2, -4, LAT1, -2) transporters, insulin signaling, and System A transporter activity was determined. Neonatal fat mass (%) was measured in a subset of neonates born to T2DM women.

RESULTS

GLUT1 protein expression was increased (p = 0.001) and GLUT4 decreased (p = 0.006) in BM from T2DM. MVM FATP6 expression was increased (p = 0.02) and correlated with birth weight in both T2DM and NGT groups (r = 0.65, p = 0.02). BM FATP6 expression was increased (p = 0.01) in T2DM. In MVM of T2DM placentas, SNAT1 expression was increased (p = 0.05) and correlated with birth weight (r = 0.84, p = 0.004); SNAT2 was increased (p = 0.01), however System A transporter activity was not different between groups. MVM LAT1 expression was increased (p = 0.01) in T2DM and correlated with birth weight (r = 0.59, p = 0.04) and neonatal fat mass (r = 0.76, p = 0.06).

CONCLUSION

In pregnancies complicated by T2DM placental protein expression of transporters for glucose, amino acids and fatty acids is increased, which may contribute to increased fetal growth and neonatal adiposity.

Maternal diabetes and fetal cardiac output

BACKGROUND

The intrauterine environment is a key determinant for long-term health outcomes. Adverse fetal environments, such as maternal diabetes, obesity and placental insufficiency are strongly associated with long-term health risks in children. Little is known about differences in fetal cardiac output hemodynamics of diabetic mothers (DM) vs. non-diabetic mothers (NDM). Our study aims to investigate the left-sided, right-sided, and combined cardiac output (CCO) in fetuses of DM vs. NDM.

METHODS

Retrospective data were collected in fetuses of DM (N = 532) and NDM (103) at mean gestational age 24 weeks. Examination included 2D echo and pulse wave Doppler. Wilcoxon rank sum tests and Chi-square tests were used to test for distribution difference of maternal and fetal continuous and categorical measures respectively between DM and NDM. Intraclass correlation coefficients were calculated to assess intra-observer reliability of fetal cardiac measurements.

RESULTS

DM mothers had higher mean weight (89.7±22.2 kg) than NDM (76.8±19.8 kg), p <  0.0001 and higher mean BMI (33.4±7.5) than NDM (28.3±5.8), p <  0.0001. C-section delivery occurred in 66% of DM vs. 35% of NDM fetuses. Fetuses of DM mothers had significantly larger semilunar valve diameter, higher left ventricular (LV) output, higher combined cardiac output and lower right ventricle /left ventricle ratio compared to NDM.

CONCLUSION

The greater CCO (adjusted for fetal weight), left sided cardiac output in the fetuses of DM, compared to NDM, represent differences in cardiac adaptation to the diabetic environment.

Effects of Maternal Obesity On Placental Phenotype

The incidence of obesity is rising rapidly worldwide with the consequence that more women are entering pregnancy overweight or obese. This leads to an increased incidence of clinical complications during pregnancy and of poor obstetric outcomes. The offspring of obese pregnancies are often macrosomic at birth although there is also a subset of the progeny that are growth-restricted at term. Maternal obesity during pregnancy is also associated with cardiovascular, metabolic and endocrine dysfunction in the offspring later in life. As the interface between the mother and fetus, the placenta has a central role in programming intrauterine development and is known to adapt its phenotype in response to environmental conditions such as maternal undernutrition and hypoxia. However, less is known about placental function in the abnormal metabolic and endocrine environment associated with maternal obesity during pregnancy. This review discusses the placental consequences of maternal obesity induced either naturally or experimentally by increasing maternal nutritional intake and/or changing the dietary composition. It takes a comparative, multi-species approach and focusses on placental size, morphology, nutrient transport, metabolism and endocrine function during the later stages of obese pregnancy. It also examines the interventions that have been made during pregnancy in an attempt to alleviate the more adverse impacts of maternal obesity on placental phenotype. The review highlights the potential role of adaptations in placental phenotype as a contributory factor to the pregnancy complications and changes in fetal growth and development that are associated with maternal obesity.

Effects of Maternal Obesity and Gestational Diabetes Mellitus on the Placenta: Current Knowledge and Targets for Therapeutic Interventions

Obesity and gestational diabetes mellitus (GDM) are becoming more common among pregnant women worldwide and are individually associated with a number of placenta-mediated obstetric complications, including preeclampsia, macrosomia, intrauterine growth restriction and stillbirth. The placenta serves several functions throughout pregnancy and is the main exchange site for the transfer of nutrients and gas from mother to fetus. In pregnancies complicated by maternal obesity or GDM, the placenta is exposed to environmental changes, such as increased inflammation and oxidative stress, dyslipidemia, and altered hormone levels. These changes can affect placental development and function and lead to abnormal fetal growth and development as well as metabolic and cardiovascular abnormalities in the offspring. This review aims to summarize current knowledge on the effects of obesity and GDM on placental development and function. Understanding these processes is key in developing therapeutic interventions with the goal of mitigating these effects and preventing future cardiovascular and metabolic pathology in subsequent generations.

Personalized Nutrition Approach in Pregnancy and Early Life to Tackle Childhood and Adult Non-Communicable Diseases

The development of childhood and adult non-communicable diseases (NCD) is associated with environmental factors, starting from intrauterine life. A new theory finds the roots of epigenetic programming in parental gametogenesis, continuing during embryo development, fetal life, and finally in post-natal life. Maternal health status and poor nutrition are widely recognized as implications in the onset of childhood and adult diseases. Early nutrition, particularly breastfeeding, also plays a primary role in affecting the health status of an individual later in life. A poor maternal diet during pregnancy and lack of breastfeeding can cause a nutrient deficiency that affects the gut microbiota, and acts as a cofactor for many pathways, impacting the epigenetic controls and transcription of genes involved in the metabolism, angiogenesis, and other pathways, leading to NCDs in adult life. Both maternal and fetal genetic backgrounds also affect nutrient adsorption and functioning at the cellular level. This review discusses the most recent evidence on maternal nutrition and breastfeeding in the development of NCD, the potentiality of the omics technologies in uncovering the molecular mechanisms underlying it, with the future prospective of applying a personalized nutrition approach to prevent and treat NCD from the beginning of fetal life.

Associations Between Maternal Lifetime Stress and Placental Mitochondrial DNA Mutations in an Urban Multiethnic Cohort

BACKGROUND

Disrupted placental functioning due to stress can have lifelong implications. Cumulative stress and trauma are likely to have lasting impacts on maternal physiological functioning and offspring development, resulting in increased risk for later-life complex disorders for which racial disparities exist.

METHODS

This study examined the association between maternal lifetime stress and placental mitochondrial DNA mutational load in an urban multiethnic cohort. Maternal lifetime exposure to stressful events was assessed using the validated Life Stressor Checklist-Revised. Whole mitochondrial DNA sequencing was performed and mutations were determined for 365 placenta samples with complete exposure and covariate data. Multivariable regression was used to model maternal lifetime stress in relation to placental mitochondrial DNA mutational load. Racial/ethnic differences were examined by cross-product terms and contrast statements. Gene-wise analyses were conducted.

RESULTS

We identified 13,189 heteroplasmies (Phred score > 10,000, minor allele frequency < 0.5, number of mutant reads > 1). Women experiencing increased psychosocial stress over their lifetime exhibited a higher number of total placental mitochondrial mutations (β = .23, 95% confidence interval = .03 to .42) and heteroplasmic mutations (β = .18, 95% confidence interval = .05 to .31) but not homoplasmic mutations (β = -.008, 95% confidence interval = -.03 to .01); the strongest associations were observed among Black women and genes coding for NADH dehydrogenase and cytochrome c oxidase subunits.

CONCLUSIONS

Cumulative maternal lifetime stress is associated with a greater mitochondrial mutational load, particularly among Black women. The impact of racial/ethnic differences in mutational load on placental function directly affecting offspring development and/or leading to chronic disease disparities warrants further investigation.

Self-Reported DHA Supplementation during Pregnancy and Its Association with Obesity or Gestational Diabetes in Relation to DHA Concentration in Cord and Maternal Plasma: Results from NELA, a Prospective Mother-Offspring Cohort

Maternal supplementation of docosahexaenoic acid (DHA) during pregnancy has been recommended due to its role in infant development, but its effect on materno-fetal DHA status is not well established. We evaluated the associations between DHA supplementation in pregnant women with obesity or gestational diabetes mellitus (GDM) and maternal and neonatal DHA status. Serum fatty acids (FA) were analyzed in 641 pregnant women (24 weeks of gestation) and in 345 venous and 166 arterial cord blood samples of participants of the NELA cohort. Obese women (n = 47) presented lower DHA in serum than those lean (n = 397) or overweight (n = 116) before pregnancy. Linoleic acid in arterial cord was elevated in obese women, which indicates lower fetal retention. Maternal DHA supplementation (200 mg/d) during pregnancy was associated with enhanced maternal and fetal DHA levels regardless of pre-pregnancy body mass index (BMI), although higher arterial DHA in overweight women indicated an attenuated response. Maternal DHA supplementation was not associated with cord venous DHA in neonates of mothers with GDM. The cord arteriovenous difference was similar for DHA between GDM and controls. In conclusion, maternal DHA supplementation during pregnancy enhanced fetal DHA status regardless of the pre-pregnancy BMI while GDM may reduce the effect of DHA supplementation in newborns.

Hyperglycemia and gestational diabetes suppress placental glycolysis and mitochondrial function and alter lipid processing

The degree that maternal glycemia affects placental metabolism of trophoblast cell types [cytotrophoblast (CTB) and syncytiotrophoblast (SCT)] in pregnant persons with gestational diabetes mellitus (GDM) is unknown. We tested the hypotheses that (a) hyperglycemia suppresses the metabolic rates of CTB and SCT; and (b) low placental metabolic activity from GDM placentas is due to decreased oxygen consumption of CTB. Trophoblast cells isolated from GDM and non-GDM term placentas were cultured for 8-hour (CTB) and following syncytialization at 72-hour (SCT) in 5 mM of glucose or 25 mM of glucose. Oxygen consumption rates, glycolysis, ATP levels, and lipid droplet morphometries were determined in CTB and SCT. In CTB from GDM placentas compared to control CTB: (a) oxidative phosphorylation was decreased by 44% (41.8 vs 74.2 pmol O₂ /min/100 ng DNA, P = .002); (b) ATP content was 39% lower (1.1 × 10^-7 vs 1.8 × 10^-7  nM/ng DNA, P = .046); and (c) lipid droplets were two times larger (31.0 vs 14.4 µm² /cell, P < .001) and 1.7 times more numerous (13.5 vs 7.9 lipid droplets/cell, P < .001). Hyperglycemia suppressed CTB glycolysis by 55%-60% (mean difference 20.4 [GDM, P = .008] and 15.4 [non-GDM, P = .029] mpH/min/100 ng DNA). GDM SCT was not metabolically different from non-GDM SCT. However, GDM SCT had significantly decreased expression of genes associated with differentiation including hCG, GCM1, and syncytin-1. We conclude that suppressed metabolic activity by the GDM placenta is attributable to metabolic dysfunction of CTB, not SCT. Critical placental hormone expression and secretion are decreased in GDM trophoblasts.

Placental mobilization of free fatty acids contributes to altered materno-fetal transfer in obesity

BACKGROUND

Metabolic changes in obese pregnant women, such as changes of plasma lipids beyond physiological levels, may subsequently affect fetal development in utero. These metabolic derangements may remain in the offspring and continue throughout life. The placenta mediates bidirectional exchange of nutrients between mother and fetus. The impact of prepregnancy obesity on placental transfer of lipids is still unknown.

OBJECTIVE

We aimed to examine materno-to-fetal free fatty acid (FFA) transfer by a combined experimental and modeling approach. Flux of ¹³C-labeled FFA was evaluated by ex vivo perfusion of human placentae as a function of prepregnancy obesity. Mathematical modeling complemented ex vivo results by providing FFA kinetic parameters.

RESULTS

Obesity was strongly associated with elevated materno-to-fetal transfer of applied ¹³C-FFA. Clearance of polyunsaturated ¹³C-docosahexaenoic acid (DHA) was most prominently affected. The use of the mathematical model revealed a lower tissue storage capacity for DHA in obese compared with lean placentae.

CONCLUSION

Besides direct materno-to-fetal FFA transfer, placental mobilization accounts for the fetal FA supply. Together, with metabolic changes in the mother and an elevated materno-fetal FFA transfer shown in obesity, these changes suggest that they may be transmitted to the fetus, with yet unknown consequences.

Higher Levels of Triglyceride, Fatty Acid Translocase, and Toll-Like Receptor 4 and Lower Level of HDL-C in Pregnant Women with GDM and Their Close Correlation with Neonatal Weight

OBJECTIVES

In this study, we aimed to compare the levels of maternal blood lipids, placental and venous blood lipid transporters, and inflammatory factor receptors in pregnant women with and without gestational diabetes mellitus (GDM). We also aimed to figure out the relationship between these values and neonatal weight.

METHODS

Fifty pregnant women with GDM under blood glucose control belong to the case group, and 50 pregnant women with normal glucose tolerance in concurrent delivery belong to the control group. Fasting venous blood of these pregnant women was taken 2 weeks before delivery, and umbilical cord blood was collected after delivery. The levels of triglyceride (TG), serum total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (HDL-C) in maternal blood and umbilical cord blood were tested in the laboratory department of our hospital. The level of toll-like receptor 4 (TLR4) in serum of umbilical veins was detected by the double-antibody sandwich ELISA. Western blot and RT-PCR were used to detect the protein and mRNA expressions of TLR4, LPL, and FAT/CD36 in the placenta.

RESULTS

The level of TG in maternal blood in the case group was remarkably higher than that in the control group, which was opposite to the level of HDL-C. In the umbilical cord blood of women with GDM, the expression of TLR4 increased and was closely correlated with neonatal weight. In the placenta of women with GDM, the expressions of FAT/CD36 and TLR4 increased, and both of them were closely correlated with neonatal weight. Besides, TLR4 in umbilical cord blood increased and was closely correlated with neonatal weight. Although the expression of LPL in the placenta decreased, it had no obvious correlation with neonatal weight.

CONCLUSIONS

TG in maternal blood, TLR4 in the placenta and umbilical cord blood, and FAT/CD36 in the placenta were positively correlated with neonatal weight. However, HDL-C in maternal blood was negatively correlated with neonatal weight. Although the expression of LPL in the placenta reduced due to GDM, it had no correlation with neonatal weight.

Abnormalities of Serum Fatty Acids in Children With Henoch-Schönlein Purpura by GC-MS Analysis

Purpose: The objectives of this work were to test the levels of serum medium- and long- chain fatty acids (MLCFAs) in children and to discover their possible relationship with Henoch-Schönlein Purpura (HSP), also known as Immunoglobulin A vasculitis. Methods: A total of 57 children with HSP (HSP group) and 28 healthy children (CON group) were recruited for this study. Serum specimens were collected to detect the compositions and contents of MLCFAs by gas chromatography with mass spectrometry (GC-MS) analysis. Results: The contents of all detected 37 MLCFAs in the HSP group were higher than the healthy group. Thirty-one species of MLCFAs were discovered to have a significant difference (p < 0.05) in two groups. Comparing to healthy controls, there were 31, 31, 18 fatty acids showed a statistical difference in the untreated group, regular treated group, and withdrawal group of HSP, respectively. The trend of fatty acids in the three HSP groups was similar to the healthy controls, as well as the untreated group and regular treated group changed more obviously than the withdrawal group. Almitate (C16:0) and 18 carbon atoms (C18) of fatty acids were abundant in all three HSP groups, divided according to the treatment of glucocorticoid. Some fatty acids were found having considerable differences (p < 0.05) in three groups. Monounsaturated fatty acids (MUFAs), including elaidate (C18:1T), cis-11,14,17-eicosatrienoic acid ester (C20:1), and cis-15-tetracosenoate (C24:1), were distinctly higher in HSP children with renal damage. Conclusion: Our study revealed that the abnormalities in MLCFA may be associated with the development of HSP. Another interesting finding was that fatty acids contents were changing during the glucocorticoid treatment. Meanwhile, long-chain MUFAs may have an impact on renal damage in HSP patients. Further studies need to be carried out in order to explore the specific mechanism of fatty acids in the course of HSP.

Brief high fat high sugar diet results in altered energy and fat metabolism during pregnancy in mice

During pregnancy several maternal adaptations occur in order to support the growing fetus which are further exacerbated by gestational diabetes mellitus (GDM). Previously we developed a mouse model of GDM, however we did not evaluate alterations to energy and fat metabolism. We have also shown that alterations in lipid metabolism are mediated by adrenomedullin (ADM) in normal and GDM pregnancies. Our objectives were: (1) evaluate energy and fat homeostasis in our GDM mouse model and (2) determine if ADM may play a role in these changes. Female mice were placed on either control (P-CD) or high fat, high sucrose diet (P-HFHS) 1 week prior to and throughout pregnancy. Mice were placed into comprehensive lab animal monitoring system (CLAMS) chambers throughout pregnancy. Visceral adipose tissue (VAT) was collected at d17.5 of pregnancy for analysis. Energy Expenditure was significantly increased (p < 0.05) in P-HFHS dams compared to all other groups. VAT ex-vivo lipolysis was increased (p < 0.05) in P-HFHS compared to P-CD dams. VAT gene expression of ADM receptors Crlr, Ramp2, and Ramp3 was increased (p < 0.05) in P-HFHS dams. ADM dose dependently increased ex vivo lipolysis. This data further validates our animal model of GDM and is usefulness in investigating the pathophysiology of GDM.

Maternal obesity alters placental lysophosphatidylcholines, lipid storage, and the expression of genes associated with lipid metabolism‡

Dyslipidemia is a characteristic of maternal obesity and previous studies have demonstrated abnormalities in fatty acid oxidation and storage in term placentas. However, there is little information about the effect of pre-pregnancy obesity on placental lipid metabolism during early pregnancy. The objective of this study was to determine the relationship between lipid profiles and markers of metabolism in placentas from obese and lean dams at midgestation. Mice were fed a western diet (WD) or normal diet (ND) and lysophosphatidylcholines (LPCs) and/or phosphatidylcholines (PCs) were measured in dam circulation and placenta sections using liquid chromatography-tandem mass spectrometry and mass spectrometry imaging, respectively. In WD dam, circulating LPCs containing 16:1, 18:1, 20:0, and 20:3 fatty acids were increased and 18:2 and 20:4 were decreased. In WD placenta from both sexes, LPC 18:1 and PC 36:1 and 38:3 were increased. Furthermore, there were moderate to strong correlations between LPC 18:1, PC 36:1, and PC 38:3. Treatment-, spatial-, and sex-dependent differences in LPC 20:1 and 20:3 were also detected. To identify genes that may regulate diet-dependent differences in placenta lipid profiles, the expression of genes associated with lipid metabolism and nutrient transport was measured in whole placenta and isolated labyrinth using droplet digital PCR and Nanostring nCounter assays. Several apolipoproteins were increased in WD placentas. However, no differences in nutrient transport or fatty acid metabolism were detected. Together, these data indicate that lipid storage is increased in midgestation WD placentas, which may lead to lipotoxicity, altered lipid metabolism and transport to the fetus later in gestation.

The Impact of Maternal Body Composition and Dietary Fat Consumption upon Placental Lipid Processing and Offspring Metabolic Health

The proportion of women of reproductive age who are overweight or obese is increasing globally. Gestational obesity is strongly associated in both human studies and animal models with early-onset development of adult-associated metabolic diseases including metabolic syndrome in the exposed offspring. However, animal model studies have suggested that gestational diet in obese pregnancies is an independent but underappreciated mediator of offspring risk for later life metabolic disease, and human diet consumption data have highlighted that many women do not follow nutritional guidelines prior to and during pregnancy. Thus, this review will highlight how maternal diet independent from maternal body composition impacts the risk for later-life metabolic disease in obesity-exposed offspring. A poor maternal diet, in combination with the obese metabolic state, are understood to facilitate pathological in utero programming, specifically through changes in lipid handling processes in the villous trophoblast layer of the placenta that promote an environment associated with the development of metabolic disease in the offspring. This review will additionally highlight how maternal obesity modulates villous trophoblast lipid processing functions including fatty acid transport, esterification and beta-oxidation. Further, this review will discuss how altering maternal gestational diet may ameliorate these functional changes in lipid metabolic processes in the obese placenta.

Association of Maternal DNA Methylation and Offspring Birthweight

This study aims to evaluate the association of maternal DNA methylation (DNAm) during pregnancy and offspring birthweight. One hundred twenty-two newborn-mother dyads from the Isle of Wight (IOW) cohort were studied to identify differentially methylated cytosine-phosphate-guanine sites (CpGs) in maternal blood associated with offspring birthweight. Peripheral blood samples were drawn from mothers at 22-38 weeks of pregnancy for epigenome-wide DNAm assessment using the Illumina Infinium HumanMethylation450K array. Candidate CpGs were identified using a course of 100 repetitions of a training and testing process with robust regressions. CpGs were considered informative if they showed statistical significance in at least 80% of training and testing samples. Linear mixed models adjusting for covariates were applied to further assess the selected CpGs. The Swedish Born Into Life cohort was used to replicate our findings (n = 33). Eight candidate CpGs corresponding to the genes LMF1, KIF9, KLHL18, DAB1, VAX2, CD207, SCT, SCYL2, DEPDC4, NECAP1, and SFRS3 in mothers were identified as statistically significantly associated with their children's birthweight in the IOW cohort and confirmed by linear mixed models after adjusting for covariates. Of these, in the replication cohort, three CpGs (cg01816814, cg23153661, and cg17722033 with p values = 0.06, 0.175, and 0.166, respectively) associated with four genes (LMF1, VAX2, CD207, and NECAP1) were marginally significant. Biological pathway analyses of three of the genes revealed cellular processes such as endocytosis (possibly sustaining an adequate maternal-fetal interface) and metabolic processes such as regulation of lipoprotein lipase activity (involved in providing substrates for the developing fetus). Our results contribute to an epigenetic understanding of maternal involvement in offspring birthweight. Measuring DNAm levels of maternal CpGs may in the future serve as a diagnostic tool recognizing mothers at risk for pregnancies ending with altered birthweights.

Placental function in maternal obesity

Maternal obesity is associated with pregnancy complications and increases the risk for the infant to develop obesity, diabetes and cardiovascular disease later in life. However, the mechanisms linking the maternal obesogenic environment to adverse short- and long-term outcomes remain poorly understood. As compared with pregnant women with normal BMI, women entering pregnancy obese have more pronounced insulin resistance, higher circulating plasma insulin, leptin, IGF-1, lipids and possibly proinflammatory cytokines and lower plasma adiponectin. Importantly, the changes in maternal levels of nutrients, growth factors and hormones in maternal obesity modulate placental function. For example, high insulin, leptin, IGF-1 and low adiponectin in obese pregnant women activate mTOR signaling in the placenta, promoting protein synthesis, mitochondrial function and nutrient transport. These changes are believed to increase fetal nutrient supply and contribute to fetal overgrowth and/or adiposity in offspring, which increases the risk to develop disease later in life. However, the majority of obese women give birth to normal weight infants and these pregnancies are also associated with activation of inflammatory signaling pathways, oxidative stress, decreased oxidative phosphorylation and lipid accumulation in the placenta. Recent bioinformatics approaches have expanded our understanding of how maternal obesity affects the placenta; however, the link between changes in placental function and adverse outcomes in obese women giving birth to normal sized infants is unclear. Interventions that specifically target placental function, such as activation of placental adiponectin receptors, may prevent the transmission of metabolic disease from obese women to the next generation.

A mid-pregnancy risk prediction model for gestational diabetes mellitus based on the maternal status in combination with ultrasound and serological findings

Although previous studies have proposed predictive models of gestational diabetes mellitus (GDM) based on maternal status, they do not always provide reliable results. The present study aimed to create a novel model that included ultrasound data of maternal fat distribution and serum inflammatory factors. The clinical data of 1,158 pregnant women treated at Tangshan Gongren Hospital and eight other flagship hospitals in Tangshan, including the First Hospital of Tangshan Gongren Hospital group, Ninth Hospital of Tangshan Gongren Hospital group, Tangshan Gongren Hospital group rehabilitation hospital, Tangshan railway central hospital, Tangshan Gongren Hospital group Fengnan hospital, Tangshan Gongren Hospital group Qianan Yanshan hospital, Tangshan Gongren Hospital group Qianxi Kangli hospital and Tangshan Gongren Hospital group Jidong Sub-hospital, were analyzed following the division of subjects into GDM and non-GDM groups according to their diagnostic results at 24-28 weeks of pregnancy. Univariate analysis was performed to investigate the significance of the maternal clinical parameters for GDM diagnosis and a GDM prediction model was established using stepwise regression analysis. The predictive value of the model was evaluated using a Homer-Lemeshow goodness-of-fit test and a receiver operating characteristic curve (ROC). The model demonstrated that age, pre-pregnancy body mass index, a family history of diabetes mellitus, polycystic ovary syndrome, a history of GDM, high systolic pressures, glycosylated hemoglobin levels, triglyceride levels, total cholesterol levels, low-density lipoprotein cholesterol levels, serum hypersensitive C-reactive protein, increased subcutaneous fat thickness and visceral fat thickness were all correlated with an increased GDM risk (all P<0.01). The area under the curve value was 0.911 (95% CI, 0.893-0.930). Overall, the results indicated that the current model, which included ultrasound and serological data, may be a more effective predictor of GDM compared with other single predictor models. In conclusion, the present study developed a tool to determine the risk of GDM in pregnant women during the second trimester. This prediction model, based on various risk factors, demonstrated a high predictive value for the GDM occurrence in pregnant women in China and may prove useful in guiding future clinical practice.

Exploring the role of oxidative stress, fatty acids and neurotrophins in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) constitutes an unfavorable intrauterine environment for embryonic and feto-placental development. Women with GDM are at higher risk for materno-fetal complications and placental abnormalities. The placenta acts as an interface between the maternal and fetal circulations and also plays an important role in protecting the fetus from adverse effects of maternal metabolic conditions. One of the earliest abnormalities observed in GDM pregnancies is increased oxidative stress in the placenta which affects fetal development. Imbalances in maternal nutrition particularly long-chain polyunsaturated fatty acid (LCPUFA) intake and/or metabolism lead to increased oxidative stress. Reports indicate that oxidative stress and LCPUFA such as docosahexaenoic acid affect the levels of neurotrophins. The present review aims to provide insights into a mechanistic link between oxidative stress, LCPUFA and neurotrophin in the placenta in women with GDM and its implications for neurodevelopmental outcomes in children.