The Feto-placental Dialogue and Diabesity

Placental dysfunction in obese women and antenatal surveillance

Obesity is a significant health concern worldwide and is associated with numerous health complications, including placental dysfunction during pregnancy. Placental dysfunction can lead to adverse outcomes for both the mother and the foetus, such as preeclampsia, gestational diabetes, preterm birth, and foetal growth restriction. Studies have shown that maternal obesity can lead to placental dysfunction through various mechanisms, including chronic inflammation, oxidative stress, and dysregulation of metabolic pathways. These factors can contribute to changes in the placenta's structure and function, impairing nutrient and oxygen exchange between the mother and foetus. Recent research has also suggested that alteration of gene expression in the placenta due to epigenetic changes, such as DNA methylation, may play a role in placental dysfunction associated with maternal obesity. These changes can affect altering foetal growth and development. Prevention and management of maternal obesity are crucial in reducing the risk of placental dysfunction and associated adverse outcomes during pregnancy. This can be achieved through lifestyle modifications, such as diet and exercise, and early detection and management of underlying health conditions. In conclusion, maternal obesity is a significant risk factor for placental dysfunction during pregnancy, which can lead to adverse outcomes for both the mother and the foetus. Further research is needed to understand the relationship and mechanisms to develop effective interventions to prevent and manage placental dysfunction in obese pregnant women.

Antenatal depression moderated the association between gestational diabetes mellitus and fetal hyperinsulinism

BACKGROUND

Gestational diabetes mellitus and antenatal depression are common comorbidities. However, the combined effects of antenatal depression and diabetes mellitus during pregnancy on fetal β-cell function are unknown.

OBJECTIVE

This study aimed to test whether the association of maternal gestational diabetes mellitus and glucose metabolism with cord blood C-peptide levels varies with antenatal depression.

STUDY DESIGN

Data on mother-child pairs (N=5734) from the Maternal and Infant Health Cohort Study in Hefei were analyzed. Gestational diabetes mellitus was diagnosed using the 75-g oral glucose tolerance test at 24 to 28 weeks of gestation. Antenatal depression was measured using the Edinburgh Postnatal Depression Scale during midpregnancy and late pregnancy. Cord blood samples were collected at delivery and tested for C-peptide levels.

RESULTS

A total of 1054 mothers (18.38%) were diagnosed with gestational diabetes mellitus. Gestational diabetes mellitus was associated with a 5.57 (95% confidence interval, 3.65-7.50) percentile higher cord blood C-peptide level. This association varied with depression severity: the differences in cord blood C-peptide percentile for gestational diabetes mellitus vs no gestational diabetes mellitus were 5.12 (95% confidence interval, 2.81-9.75) for nonantenatal depression, 7.36 (95% confidence interval, 2.85-13.38) for moderate antenatal depression, and 10.06 (95% confidence interval, 4.69-14.8) for severe antenatal depression in midpregnancy. Similar associations stratified by antenatal depression in late pregnancy were observed. Antenatal depression was significantly positively correlated with fetal hyperinsulinism in participants with gestational diabetes mellitus but not in participants without gestational diabetes mellitus.

CONCLUSION

Antenatal depression, which is related to maternal hyperglycemia, can aggravate the risk of fetal hyperinsulinism in early life.

The Impact of Obesity on Reproductive Health and Pregnancy Outcomes

Women carry the majority of the burden of our obesogenic surroundings, with a larger prevalence of obesity than males, a greater impact on fertility and treatment success, and increased maternal and perinatal morbidity and death. Obesity and its associated morbidity are now among our most pressing global health concerns. Women are more susceptible to gaining weight, which has reproductive, coronary, and emotional consequences. The current data on the negative consequences of obesity before conception (fertility issues, assisted reproductive treatment, polycystic ovary disease, overweight and obesity preventative measures, and emotional well-being), pregnancy (preventing excess gestational body weight, gestational diabetes, and preeclampsia, as well as labor and newborn health), and following delivery (the lactation process and breastfeeding, postnatal weight retention, and depressive symptoms) health is summarized. in this review. Along with this, underlying factors, consequences, and solutions to the obesity pandemic are investigated, as well as the mechanisms of obesity's effect on women and men, the epigenetic consequences of masculine obesity, its significant effects on reproductive results, and the implications of the loss of weight preceding to pregnancy as well as during pregnancy. This review suggests study methodologies that might assist in guiding attempts to enhance reproductive health and neonatal health in obese or overweight women.

Alterations of materno-placento-fetal glucose homeostasis after a single course of antenatal betamethasone

INTRODUCTION

Intrauterine growth impairment is associated with long-term metabolic changes (perinatal programming). We recently demonstrated that antenatal betamethasone (BET) decreased head circumference in term born females. Since glucose is the main energy source for fetal growth, BET-induced changes in maternal glucose homeostasis, a reduced transplacental glucose transfer or an altered fetal glucose utilization may be linked with the observed growth impairment.

METHODS

86 pregnant women exposed to BET (single course, <34 + 0 weeks of gestation (wks)) were compared to 92 gestational-age/sex-matched controls. Glucose, insulin, leptin, insulin-like growth factors (IGF-1, IGF-2) and their binding proteins (IGFBP-1, IGFBP-3) were measured in maternal and umbilical cord blood samples. Homeostasis Model Assessment (HOMA-IR) was calculated. Placental glucose transporter 1 and 3 (GLUT1, GLUT3) protein levels were determined. Statistics were performed for overall and subgroup analysis (gestational age, sex).

RESULTS

After BET maternal HOMA-IR was elevated, IGFBP-1 reduced. In female pregnancies, glucose levels ≥37 + 0 wks and IGF-1 levels <37 + 0 wks were tendentially increased. Placental GLUT1 and GLUT3 protein levels were not significantly altered. Fetal umbilical venous glucose levels ≥37 + 0 wks were increased. HOMA-IR tended to be elevated in females.

DISCUSSION

Growth impairment after BET appears neither caused by maternal nor fetal hypoglycemia nor changes of GLUT1 and GLUT3 total protein levels. Nonetheless, glucose homeostasis of mothers and daughters was altered even beyond the BET time frame (hyperglycemia, enhanced insulin resistance). Despite glucose supply was sufficient, an anabolic effect was apparently absent. Overall, our results highlight the relevance of adequate glucose management after BET and peripartum.

Associations between the maternal healthy lifestyle score and its individual components during early pregnancy with placental outcomes

INTRODUCTION

The influence of maternal lifestyle behaviours on placental growth have been investigated individually, but with conflicting results, and their combined effect is under-researched. Therefore, we examined associations between a composite maternal healthy lifestyle score (HLS), and its individual components, during early pregnancy with placental outcomes.

METHODS

Participants included Lifeways Cross-Generational Cohort mother-child pairs (n = 202). A composite HLS based on a less inflammatory diet (bottom 40% of the energy-adjusted Dietary Inflammatory Index (E-DII™)), moderate-to-vigorous physical activity (MVPA), healthy pre-pregnancy BMI (18.5-24.9 kg/m²), never smoking, and non-/moderate alcohol intake was calculated. Quantile regression analysed HLS (and individual components) associations with measures of placental development (untrimmed placental weight (PW)) and function (birth weight:placental weight (BW:PW) ratio) at the 10th, 25th, 50th, 75th and 90th centiles.

RESULTS

A more pro-inflammatory diet was positively, and smoking and heavy alcohol consumption were negatively, associated with PW at median centiles (B: 41.97 g, CI: 3.71, 80.22, p < 0.05; B: -58.51 g, CI: -116.24, -0.77, p < 0.05; B: -120.20 g, CI: -177.97, -62.43, p < 0.05 respectively). Low MVPA was inversely associated with BW:PW ratio at the 10th and 90th centiles (B: -0.36, CI: -0.132, -0.29, p < 0.01 and B: -0.45, CI: -0.728, -0.182, p < 0.01, respectively). Heavy alcohol intake was positively associated with BW:PW ratio at the 10th centile (B: 0.54, CI: 0.24, 0.85, p < 0.01). Results of sex-stratified analysis provide evidence of sexual dimorphism.

DISCUSSION

Associations of certain lifestyle factors, but not the composite HLS, during early pregnancy with measures of placental development (PW) and function (BW:PW ratio) varied by quantiles and by sex.

Placental and plasma early predictive biomarkers for gestational diabetes mellitus

PURPOSE

Gestational diabetes mellitus (GDM) is a common disease that can give rise to adverse obstetric outcomes. For successful early intervention, more studies on novel predictive biomarkers for GDM are required.

EXPERIMENTAL DESIGN

The protein expression profiles of placental tissue from patients with GDM and normal pregnant women were investigated using data-independent acquisition proteomics with five biological replicates. Early pregnancy maternal plasma samples from the GDM (n = 79) and control (n = 81) groups were used for further validation of candidate biomarkers.

RESULTS

We identified 37 differentially expressed proteins between the two groups. CD109 antigen (CD109) and endosialin (CD248) were identified as hub proteins. In the validation experiments, CD109 expression was lower in the early pregnancy maternal plasma of patients with GDM compared with that in normal pregnant women, and CD248 expression was higher in the GDM group. The area under the curve of CD109, CD248, and their combination as indicators in early pregnancy maternal plasma was 0.681, 0.609, and 0.695, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

The present study is the first to obtain preliminary evidence that CD109 and CD248 can predict GDM during early pregnancy, as well as providing proteome-level insights into this disease's pathological mechanisms.

Programming of cardiometabolic health: the role of maternal and fetal hyperinsulinaemia

Obesity and gestational diabetes during pregnancy have multiple short- and long-term consequences for both mother and child. One common feature of pregnancies complicated by maternal obesity and gestational diabetes is maternal hyperinsulinaemia, which has effects on the mother and her adaptation to pregnancy. Even though insulin does not cross the placenta insulin can act on the placenta as well affecting placental growth, angiogenesis and lipid metabolism. Obese and gestational diabetic pregnancies are often characterised by maternal hyperglycaemia resulting in exposure of the fetus to high levels of glucose, which freely crosses the placenta. This leads to stimulation of fetal ß-cells and insulin secretion in the fetus. Fetal hyperglycaemia/hyperinsulinaemia has been shown to cause multiple complications in fetal development, such as altered growth trajectories, impaired neuronal and cardiac development and early exhaustion of the pancreas. These changes could increase the susceptibility of the offspring to develop cardiometabolic diseases later in life. In this review, we aim to summarize and review the mechanisms by which maternal and fetal hyperinsulinaemia impact on (i) maternal health during pregnancy; (ii) placental and fetal development; (iii) offspring energy homeostasis and long-term cardiometabolic health; (iv) how interventions can alleviate these effects.

Exposome and foetoplacental vascular dysfunction in gestational diabetes mellitus

A balanced communication between the mother, placenta and foetus is crucial to reach a successful pregnancy. Several windows of exposure to environmental toxins are present during pregnancy. When the women metabolic status is affected by a disease or environmental toxin, the foetus is impacted and may result in altered development and growth. Gestational diabetes mellitus (GDM) is a disease of pregnancy characterised by abnormal glucose metabolism affecting the mother and foetus. This disease of pregnancy associates with postnatal consequences for the child and the mother. The whole endogenous and exogenous environmental factors is defined as the exposome. Endogenous insults conform to the endo-exposome, and disruptors contained in the immediate environment are the ecto-exposome. Some components of the endo-exposome, such as Selenium, vitamins D and B₁₂, adenosine, and a high-fat diet, and ecto-exposome, such as the heavy metals Arsenic, Mercury, Lead and Copper, and per- and polyfluoroakyl substances, result in adverse pregnancies, including an elevated risk of GDM or gestational diabesity. The impact of the exposome on the human placenta's vascular physiology and function in GDM and gestational diabesity is reviewed.

The Role of TNF-α and Anti-TNF-α Agents during Preconception, Pregnancy, and Breastfeeding

Tumor necrosis factor-alpha (TNF-α) is a multifunctional Th1 cytokine and one of the most important inflammatory cytokines. In pregnancy, TNF-α influences hormone synthesis, placental architecture, and embryonic development. It was also shown that increased levels of TNF-α are associated with pregnancy loss and preeclampsia. Increased TNF-α levels in complicated pregnancy draw attention to trophoblast biology, especially migratory activity, syncytialisation, and endocrine function. Additionally, elevated TNF-α levels may affect the maternal-fetal relationship by altering the secretory profile of placental immunomodulatory factors, which in turn affects maternal immune cells. There is growing evidence that metabolic/pro-inflammatory cytokines can program early placental functions and growth in the first trimester of pregnancy. Furthermore, early pregnancy placenta has a direct impact on fetal development and maternal immune system diseases that release inflammatory (e.g., TNF-α) and immunomodulatory factors, such as chronic inflammatory rheumatic, gastroenterological, or dermatological diseases, and may result in an abnormal release of cytokines and chemokines in syncytiotrophoblasts. Pregnancy poses a challenge in the treatment of chronic disease in patients who plan to have children. The activity of the disease, the impact of pregnancy on the course of the disease, and the safety of pharmacotherapy, including anti-rheumatic agents, in pregnancy should be considered.

Macronutrient intake during pregnancy in women with a history of obesity or gestational diabetes and offspring adiposity at 5 years of age

Background/objectives

The impact of maternal macronutrient intake during pregnancy on offspring childhood adiposity is unclear. We assessed the associations between maternal macronutrient intake during and after pregnancy with offspring adiposity at 5 years of age. Additionally, we investigated whether gestational diabetes (GDM), BMI, or breastfeeding modified these associations.

Subjects/methods

Altogether, 301 mother–child dyads with maternal prepregnancy BMI ≥ 30 and/or previous GDM participated in the Finnish Gestational Diabetes Prevention Study (RADIEL) and its 5 years follow-up. Macronutrient intakes (E%) were calculated from 3-day food records collected at 5–18 weeks’ gestation, in the third trimester, and at 12 months and 5 years after pregnancy. Offspring body fat mass (BFM) and fat percentage (BF%) at 5 years were measured by bioimpedance. Statistical analyses were multivariate linear regression.

Results

Mean (SD) prepregnancy BMI was 33(4) kg/m². GDM was diagnosed in 47%. In normoglycemic women, higher first half of pregnancy n-3 PUFA intake was associated with lower offspring BFM (g) (ß −0.90; 95% CI −1.62, −0.18) and BF% (ß −3.45; 95% CI −6.17, −0.72). In women with GDM, higher first half of pregnancy n-3 PUFA intake was associated with higher offspring BFM (ß 0.94; 95% CI 0.14, 1.75) and BF% (ß 3.21; 95% CI 0.43, 5.99). Higher SFA intake in the third trimester and cumulative intake across pregnancy (mean of the first half and late pregnancy) was associated with higher BFM and BF% (across pregnancy: ß 0.12; 95% CI 0.03, 0.20 and ß 0.44; 95% CI 0.15, 0.73, respectively). Higher carbohydrate intake across pregnancy was associated with lower BFM (ß −0.044; 95% CI −0.086, −0.003), and borderline associated with BF% (ß −0.15; 95% CI −0.31, 0.00).

Conclusions

The macronutrient composition of maternal diet during pregnancy is associated with offspring BFM and BF% at 5 years. GDM modifies the association between prenatal n-3 PUFA intake and offspring anthropometrics.

Increased placental mitochondrial fusion in gestational diabetes mellitus: an adaptive mechanism to optimize feto-placental metabolic homeostasis?

INTRODUCTION

Gestational diabetes mellitus (GDM), a common pregnancy disorder, increases the risk of fetal overgrowth and later metabolic morbidity in the offspring. The placenta likely mediates these sequelae, but the exact mechanisms remain elusive. Mitochondrial dynamics refers to the joining and division of these organelles, in attempts to maintain cellular homeostasis in stress conditions or alterations in oxygen and fuel availability. These remodeling processes are critical to optimize mitochondrial function, and their disturbances characterize diabetes and obesity.

METHODS AND RESULTS

Herein we show that placental mitochondrial dynamics are tilted toward fusion in GDM, as evidenced by transmission electron microscopy and changes in the expression of key mechanochemical enzymes such as OPA1 and active phosphorylated DRP1. In vitro experiments using choriocarcinoma JEG-3 cells demonstrated that increased exposure to insulin, which typifies GDM, promotes mitochondrial fusion. As placental ceramide induces mitochondrial fission in pre-eclampsia, we also examined ceramide content in GDM and control placentae and observed a reduction in placental ceramide enrichment in GDM, likely due to an insulin-dependent increase in ceramide-degrading ASAH1 expression.

CONCLUSIONS

Placental mitochondrial fusion is enhanced in GDM, possibly as a compensatory response to maternal and fetal metabolic derangements. Alterations in placental insulin exposure and sphingolipid metabolism are among potential contributing factors. Overall, our results suggest that GDM has profound impacts on placental mitochondrial dynamics and metabolism, with plausible implications for the short-term and long-term health of the offspring.

Palmitate induces apoptotic cell death and inflammasome activation in human placental macrophages

INTRODUCTION

There is an increasing prevalence of non-communicable diseases worldwide. Metabolic diseases such as obesity and gestational diabetes mellitus (GDM) increasingly affect women during pregnancy, which can harm pregnancy outcomes and the long-term health and wellbeing of exposed offspring. Both obesity and GDM have been associated with proinflammatory effects within the placenta, the critical organ governing fetal development.

METHODS

The purpose of these studies was to model, in vitro, the effects of metabolic stress (high levels of glucose, insulin and saturated lipids) on placental macrophage biology, since these cells are the primary innate immune phagocyte within the placenta with roles in governing maternofetal immune tolerance and antimicrobial host defense. Macrophages were isolated from the villous core of term, human placentae delivered through nonlaboring, elective Cesarean sections and exposed to combinations of elevated glucose (30 mM), insulin (10 nM) and the saturated lipid palmitic acid (palmitate, 0.4 mM).

RESULTS

We found that palmitate alone induced the activation of the nucleotide-binding oligomerization domain-like receptor (NLR) Family Pyrin Domain Containing 3 (NLRP3) inflammasome in placental macrophages, which was associated with increased interleukin 1 beta release and an increase in apoptotic cell death. Glucose and insulin neither provoked these effects nor augmented the impact of palmitate itself.

DISCUSSION

Our findings confirm an impact of saturated fat on placental macrophage immune activation and could be relevant to the impact of metabolic stress in vivo.

Diabetes Mellitus, Obesity, and the Placenta

The placenta is exposed to metabolic derangements in the maternal and fetal circulation. The effects of the early placental "exposome" determine further trajectories. Overstimulation of the fetal pancreas in early gestation results in fetal hyperinsulinemia, augmenting glucose transfer with adverse effects on the fetus. The manifold placental changes at the end of pregnancy can be regarded as adaptive responses to protect the fetus from diabetes and obesity. The causal role of the placenta, if any, in mediating long-term effects on offspring development is an important area of current and future research.

Gestational diabetes mellitus

Hyperglycaemia that develops during pregnancy and resolves after birth has been recognized for over 50 years, but uniform worldwide consensus is lacking about threshold hyperglycaemic levels that merit a diagnosis of 'gestational diabetes mellitus' (GDM) and thus treatment during pregnancy. GDM is currently the most common medical complication of pregnancy, and prevalence of undiagnosed hyperglycaemia and even overt diabetes in young women is increasing. Maternal overweight and obesity, later age at childbearing, previous history of GDM, family history of type 2 diabetes mellitus and ethnicity are major GDM risk factors. Diagnosis is usually performed using an oral glucose tolerance test (OGTT), although a non-fasting, glucose challenge test (GCT) is used in some parts of the world to screen women for those requiring a full OGTT. Dietary modification and increased physical activity are the primary treatments for GDM, but pharmacotherapy, usually insulin, is used when normoglycaemia is not achieved. Oral hypoglycaemic agents, principally metformin and glibenclamide (glyburide), are also used in some countries. Treatment improves immediate pregnancy outcomes, reducing excess fetal growth and adiposity and pregnancy-related hypertensive disorders. GDM increases the risk of long-term complications, including obesity, impaired glucose metabolism and cardiovascular disease, in both the mother and infant. Optimal management of mother and infant during long-term follow-up remains challenging, with very limited implementation of preventive strategies in most parts of the world.

Sex modifies placental gene expression in response to metabolic and inflammatory stress

INTRODUCTION

Metabolic stress (e.g., gestational diabetes mellitus (GDM) and obesity) and infections are common during pregnancy, impacting fetal development and the health of offspring. Such antenatal stresses can differentially impact male and female offspring. We sought to determine how metabolic stress and maternal immune activation (MIA), either alone or in combination, alters inflammatory gene expression within the placenta and whether the effects exhibited sexual dimorphism.

METHODS

Female C57BL/6 J mice were fed a normal diet or a high fat diet for 6 weeks prior to mating, with the latter diet inducing a GDM phenotype during pregnancy. Dams within each diet group at gestational day (GD) 12.5 received either an intraperitoneal injection of the viral mimic, polyinosinic:polycytidylic acid (poly(I:C)) or saline. Three hours post injection; placentae were collected and analyzed for changes in the expression of 248 unique immune genes.

RESULTS

Placental immune gene expression was significantly altered by GDM, MIA and the combination of the two (GDM+MIA). mRNA expression was generally lower in placentae of mice exposed to GDM alone compared with the other experimental groups, while mice exposed to MIA exhibited the highest transcript levels. Notably, fetal/placental sex influenced the responses of many immune genes to both metabolic and inflammatory stress.

DISCUSSION

GDM and MIA provoke inflammatory responses within the placenta and such effects exhibit sexual dimorphism. The combination of these stressors impacts the placenta differently than either condition alone. These findings may help explain sexual dimorphism observed in adverse pregnancy outcomes in human offspring exposed to similar stressors.

The influence of maternal pregnancy glucose concentrations on associations between a fetal imprinted gene allele score and offspring size at birth

Objective

Previously we found that certain fetal imprinted genes represented as an allele score are associated with maternal pregnancy glucose concentrations. Recently it was reported that fetal polymorphisms with strong associations with birth weight tend to mediate these independently of increases in maternal pregnancy glucose concentrations. We therefore investigated whether potential associations between the fetal allele score and birth weight were related to maternal glucose concentrations in the Cambridge Baby Growth Study.

Results

The fetal imprinted gene allele score was positively associated with birth weight (β = 63 (17–109) g/risk allele, β′ = 0.113, p = 7.6 × 10⁻³, n = 405). This association was partially attenuated by adjusting for maternal glucose concentrations (β = 50 (4–95) g/risk allele, β′ = 0.089, p = 0.03, n = 405). The allele score was also positively associated with risk of being large for gestational age at birth (odds ratio 1.60 (1.19–2.15) per risk allele, p = 2.1 × 10⁻³, n = 660) and negatively associated with risk of being small for gestational age at birth (odds ratio 0.65 (0.44–0.96) per risk allele, p = 0.03, n = 660). The large for gestational age at birth association was also partially attenuated by maternal glucose concentrations. These results suggest that associations between the fetal imprinted gene allele score and size at birth are mediated through both glucose-dependent and glucose-independent mechanisms.

Macrosomia. A Systematic Review of Recent Literature

Background and aims: The obesity and overweight rate among women of childbearing age and fetal macrosomia associated with different birth injuries are very frequent all over the world and with an increasing incidence. The huge amount of published literature on this topic in the last decade is putting the practioners in a very challenging position. Material and method: We have done a systematic review on the recent literature (last five years) based on science direct database. Results: A total of 5990 articles were identified and after successive exclusion of some of them, 48 were deeply analyzed. The results were grouped in following topics: risk factors for fetal macrosomia, the pathophysiology of macrosomia, prenatal clinical and lab diagnosis and prevention of macrosomia. Conclusions: Considering the maternal, fetal and neonatal complications of macrosomia, the counseling, and monitoring of the pregnant women risk group are of particular importance for adopting a low calorie / low glycemic diet and avoiding a sedentary behaviour. Long-term follow-up of the mother and the macrosomic baby is required because of the risk of obesity, diabetes, hypertension, and metabolic syndrome later in life.

The Human Placenta in Diabetes and Obesity: Friend or Foe? The 2017 Norbert Freinkel Award Lecture

The placenta plays a key role in sustaining fetal growth and development. Due to its position between mother and fetus, it is exposed to changes in the intrauterine environment in both circulations. The relative influence of changes in those circulations depends on the period of gestation. Early in pregnancy, maternal influences prevail and may affect the complex biological processes characteristic for this pregnancy period, such as placentation, early cell differentiation, and spiral artery remodeling. It is still unclear whether the placenta early in pregnancy is a friend or foe for the fetus. Later in pregnancy, when the fetal circulation is gradually establishing, fetal signals gain importance in regulating placental structure and function. Many of the placental alterations seen at term of pregnancy are the result of fetoplacental interactions often driven by fetal signals associated with maternal diabetes or obesity. These alterations, such as hypervascularization or enhanced cholesterol removal from placental endothelial cells, can be regarded as adaptations to maintain homeostasis at the fetoplacental interface and, thus, to protect the fetus. However, extreme conditions such as poorly controlled diabetes or pronounced obesity may exceed placental homeostatic capacity, with potentially adverse consequences for the fetus. Thus, in late pregnancy, the placenta acts mostly as a friend as long as the environmental perturbations do not exceed placental capacity for mounting adaptive responses.

Placental lipoprotein lipase activity is positively associated with newborn adiposity

INTRODUCTION

Recent data suggest that in addition to glucose, fetal growth is related to maternal triglycerides (TG). To reach the fetus, TG must be hydrolyzed to free fatty acids (FFA) and transported across the placenta, but regulation is uncertain. Placental lipoprotein lipase (pLPL) hydrolyzes TG, both dietary chylomicron TG (CM-TG) and very-low density lipoprotein TG (VLDL-TG), to FFA. This may promote fetal fat accretion by increasing the available FFA pool for placental uptake. We tested the novel hypothesis that pLPL activity, but not maternal adipose tissue LPL activity, is associated with newborn adiposity and higher maternal TG.

METHODS

Twenty mothers (n = 13 normal-weight; n = 7 obese) were prospectively recruited. Maternal glucose, insulin, TG (total, CM-TG, VLDL-TG), and FFA were measured at 14-16, 26-28, and 36-37 weeks, and adipose tissue LPL was measured at 26-28 weeks. At term delivery, placental villous biopsies were immediately analyzed for pLPL enzymatic activity. Newborn percent body fat (newborn %fat) was assessed by skinfolds.

RESULTS

Placental LPL activity was positively correlated with birthweight (r = 0.48;P = 0.03) and newborn %fat (r = 0.59;P = 0.006), further strengthened by correcting for gestational age at delivery (r = 0.75;P = 0.0001), but adipose tissue LPL was not. Maternal TG and BMI were not correlated with pLPL activity. Additionally, pLPL gene expression, while modestly correlated with enzymatic activity (r = 0.53;P < 0.05), was not correlated with newborn adiposity.

DISCUSSION

This is the first study to show a positive correlation between pLPL activity and newborn %fat. Placental lipase regulation and the role of pLPL in pregnancies characterized by nutrient excess and fetal overgrowth warrant further investigation.

Gestational diabetes mellitus is associated with increased pro-migratory activation of vascular endothelial growth factor receptor 2 and reduced expression of vascular endothelial growth factor receptor 1

Placentas from gestational diabetes mellitus (GDM) are often hypervascularized; however, participation of vascular endothelial growth factor (VEGF) and its receptors in this placental adaptation is unclear. We aimed to test whether changes in phosphorylation of tyrosine 951 or tyrosine 1175 (pY951 or pY1175) of the vascular endothelial growth factor receptor 2 (KDR) are associated with the proangiogenic state observed in placentas from GDM. We obtained placental samples from women with normal pregnancies (n = 24) or GDM (n = 18). We measured the relative expression of markers for endothelial cell number (CD31, CD34), VEGF, vascular endothelial growth factor receptor 1 (Flt-1), KDR, pY951 and pY1175 of KDR in placental homogenate. Immunohistochemistry of placental blood vessels were performed using CD34. Proliferation and migration of human umbilical vein endothelial cells (HUVEC) obtained from normal pregnancy and GDM were determined in absence or presence of conditioned medium (CM) harvested from GDM or normoglycemic HUVEC cultures. GDM was associated with more CD31 and CD34 protein compared to normal pregnancy. High number, but reduced area of placental blood vessels was found in GDM. Reduced Flt-1 levels (mRNA and protein) are associated with reduced KDR mRNA, but higher KDR protein levels in placentas from GDM. No significant changes in Y951-or Y1175-phosphorylation of KDR in placentas from GDM were found. GDM did not alter proliferation of HUVECs, but enhanced migration. Conditioned medium harvested from GDM HUVEC cultures enhanced KDR protein amount, tube formation capacity and cell migration in HUVEC isolated from normoglycemic pregnancies. The data indicate that GDM is associated with reduced expression of Flt-1 but high pro-migratory activation of KDR reflecting a proangiogenic state in GDM.

The effect of gestational diabetes, pre-gravid maternal obesity, and their combination ('diabesity') on outcomes of singleton gestations

OBJECTIVE

To assess the effect of the combination of gestational diabetes mellitus (GDM) and pre-gravid obesity ('diabesity') in singleton gestations.

METHODS

We compared perinatal outcomes of singleton gestations in mothers with GDM and pre-gravid obesity, with GDM but with normal pre-gravid BMI, and obese mothers without GDM.

RESULTS

We compared diabesity mothers (n = 1525, 24.4% of mothers with GDM, 9.9% of all obese women) to mothers with GDM but with normal BMI (n = 4704, 75.6% of mothers with GDM) and to obese mothers without GDM (n = 13,937, 90.1% of all obese mothers). Obesity, with and without GDM, increased the odds of having chronic hypertension whereas preeclampsia appears to be influenced by obesity only, as were the risk of births at <33 weeks' gestation, of birth weight >4000 g, low 5-min Apgar scores and NICU admissions.

CONCLUSION

Obesity (without diabetes) is more frequently associated with adverse perinatal outcomes than diabesity or GDM in non-obese mothers. A campaign to decrease pre-gravid obesity should have at least the same priority as any campaign to control GDM.

Effects of maternal obesity on placental function and fetal development

Obesity has reached epidemic proportions, and pregnancies in obese mothers have increased risk for complications including gestational diabetes, hypertensive disorders, pre-term birth and caesarian section. Children born to obese mothers are at increased risk of obesity and metabolic disease and are susceptible to develop neuropsychiatric and cognitive disorders. Changes in placental function not only play a critical role in the development of pregnancy complications but may also be involved in linking maternal obesity to long-term health risks in the infant. Maternal adipokines, i.e., interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), leptin and adiponectin link maternal nutritional status and adipose tissue metabolism to placental function. Adipokines and metabolic hormones have direct impact on placental function by modulating placental nutrient transport. Nutrient delivery to the fetus is regulated by a complex interaction including insulin signaling, cytokine profile and insulin responsiveness, which is modulated by adiponectin and IL-1β. In addition, obese pregnant women are at risk for hypertension and preeclampsia with reduced placental vascularity and blood flow, which would restrict placental nutrient delivery to the developing fetus. These sometimes opposing signals regulating placental function may contribute to the diversity of short and long-term outcomes observed in pregnant obese women. This review focuses on the changes in adipokines and obesity-related metabolic hormones, how these factors influence placental function and fetal development to contribute to long-term metabolic and behavioral consequences of children born to obese mothers.

The fetal glucose steal: an underappreciated phenomenon in diabetic pregnancy

Adverse neonatal outcomes continue to be high for mothers with type 1 and type 2 diabetes, and are far from eliminated in mothers with gestational diabetes mellitus. This is often despite seemingly satisfactory glycaemic control in the latter half of pregnancy. Here we argue that this could be a consequence of the early establishment of fetal hyperinsulinaemia, a driver that exaggerates the fetal glucose steal. Essentially, fetal hyperinsulinaemia, through its effect on lowering fetal glycaemia, will increase the glucose concentration gradient across the placenta and consequently the glucose flux to the fetus. While the steepness of this gradient and glucose flux will be greatest at times when maternal hyperglycaemia and fetal hyperinsulinaemia coexist, fetal hyperinsulinaemia will favour a persistently high glucose flux even at times when maternal blood glucose is normal. The obvious implication is that glycaemic control needs to be optimised very early in pregnancy to prevent the establishment of fetal hyperinsulinaemia, further supporting the need for pre-pregnancy planning and early establishment of maternal glycaemic control. An exaggerated glucose steal by a hyperinsulinaemic fetus could also attenuate maternal glucose levels during an OGTT, providing an explanation for why some mothers with fetuses with all the characteristics of diabetic fetopathy have 'normal' glucose tolerance.

TNF-α alters the inflammatory secretion profile of human first trimester placenta

Implantation and subsequent placental development depend on a well-orchestrated interaction between fetal and maternal tissues, involving a fine balanced synergistic cross-talk of inflammatory and immune-modulating factors. Tumor necrosis factor (TNF)-α has been increasingly recognized as pivotal factor for successful pregnancy, although high maternal TNF-α levels are associated with a number of adverse pregnancy conditions including gestational hypertension and gestational diabetes mellitus. This study describes effects of exogenously applied TNF-α, mimicking increased maternal TNF-α levels, on the secretion profile of inflammation associated factors in human first trimester villous placenta. Conditioned culture media from first trimester villous placental explants were analyzed by inflammation antibody arrays and ELISA after 48 h culture in the presence or absence of TNF-α. Inflammation antibody arrays identified interleukin (IL)-6, IL-8, chemokine (C-C motif) ligand 2 (CCL2), CCL4, and granulocyte-macrophage colony-stimulating factor (GM-CSF) as the most abundantly secreted inflammation-associated factors under basal culture conditions. In the presence of TNF-α, secretion of GM-CSF, CCL5, and IL-10 increased, whereas IL-4 and macrophage CSF levels decreased compared with controls. ELISA analysis verified antibody arrays by showing significantly increased synthesis and release of GM-CSF and CCL5 by placental explants in response to TNF-α. Immunohistochemistry localized GM-CSF in the villous trophoblast compartment, whereas CCL5 was detected in maternal platelets adhering to perivillous fibrin deposits on the villous surface. mRNA-based in situ padlock probe approach localized GM-CSF and CCL5 transcripts in the villous trophoblast layer and the villous stroma. Results from this study suggest that the inflammatory secretion profile of human first trimester placenta shifts towards increased levels of GM-CSF, CCL5, and IL10 in response to elevated maternal TNF-α levels, whereas IL-6 and IL-8 remain unaffected. This shift may represent a protective mechanism by human first trimester villous placenta to sustain trophoblast function and dampen inflammatory processes in the intervillous space.

Pathophysiological characteristics and effects of obesity in women with early and late manifestation of gestational diabetes diagnosed by the International Association of Diabetes and Pregnancy Study Groups criteria

CONTEXT

Appropriate risk stratification is essential in gestational diabetes (GDM) diagnosis to optimize therapeutic strategies during pregnancy. However, there are sparse data related to the newly recommended International Association of Diabetes and Pregnancy Study Groups criteria and their use in early pregnancy.

OBJECTIVE

This study sought to evaluate clinical and pathophysiological characteristics less up to gestational week (GW) 21 in women with early and late GDM onset.

DESIGN AND SETTING

This was a prospective study conducted at the Medical University of Vienna.

PATIENTS AND INTERVENTIONS

Pregnant women (n = 211) underwent an oral glucose tolerance test at 16 GW (interquartile range, 14-18 wk) with multiple measurements of glucose, insulin, and C-peptide for evaluation of insulin sensitivity and ß-cell function in addition to detailed obstetrical risk assessment. Clinical followups were performed until end of pregnancy.

MAIN OUTCOME MEASURE

We performed a metabolic characterization of early-onset GDM.

RESULTS

Of 81 women, 49 (23%) showed early (GDMEarly ≤ 21 GW) and 32 (15%) later manifestation (GDMLate ≥ 24 GW) whereas 130 (62%) remained normal-glucose-tolerant (NGT). In contrast with GDMLate, GDMEarly were affected by decreased insulin sensitivity (GDMEarly vs NGT, P < .001; GDMEarlyvs GDMLate, P < .001; GDMLate vs NGT, P = .410). However, both early and late manifested subjects showed impairments in ß-cell function. GDMEarly showed highest levels of preconceptional and actual body mass index (BMI), which was related to fasting glucose (r = 0.42, P < .001) and particularly insulin sensitivity (r = -0.51, P < .001). Differences in glucose disposal between the subgroups remained constant in multivariable analysis including the strongest risk factors for GDM, ie, age, history of GDM, and BMI in our population.

CONCLUSIONS

Early manifestation of GDM is affected by insulin resistance that is partly explained by higher degree in obesity. However, ß-cell dysfunction was also detectable in GDMLate, indicating defective compensatory mechanisms emerging already in early pregnancy.