Placental structure in gestational diabetes mellitus

Maternal prediabetes as a risk factor of preeclampsia and placental dysfunction in pregnant female Sprague-Dawley rats

BACKGROUND

Prediabetes (PD) is associated with intermediate hyperglycaemia, dyslipidaemia, reduced nitric oxide (NO) bioavailability and moderate hypertension. All these factors are risk factor for preeclampsia (PE). However, the effects of the PD on placental function have not been shown. Accordingly, this study sought to investigate a possible link between maternal PD and the risk of developing PE.

METHODS

Pregnant female Sprague-Dawley rats (N = 18) were divided into normal, preeclamptic and prediabetic groups (n = 6 in each group) to study the effects of maternal PD on placenta function over the period of 19 days. Blood glucose and blood pressure were measured on gestational day (GND) 0, 9 and 18. Placental vascular endothelial growth factor (VEGF), placenta growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1) mRNA expression were measured terminally. Data were analysed using ANOVA followed by the Tukey-Kramer post hoc test. Values of p < .05 were used to indicate statistical significance.

RESULTS

Maternal PD and PE significantly increased blood glucose, decrease NO concentration and increase in MAP by comparison to the normal pregnant control group. Maternal PD significantly decreased VEGF, PlGF mRNA expression with a slight increase in sFlt-1 mRNA expression comparison to the normal pregnant control group.

CONCLUSIONS

Maternal PD is associated with placental dysfunction due to impaired glucose handling, endothelial dysfunction and an imbalance in angiogenic and antiangiogenic factors. Therefore, maternal PD is a risk factor of PE.

Multi-type maternal diabetes mellitus affects human placental villous geometric morphology: A three-dimensional imaging study

INTRODUCTION

Diabetes mellitus leads to maldevelopment of the villous morphology in the human placenta, disrupting the exchange of materials between the maternal and fetal compartments, consequently compromising fetal development. This study aims to explore how different types of diabetes mellitus affect human placental villous geometric morphology including branching numbers and sizes (length, diameter).

METHODS

Here an optical coherence tomography (OCT)-based 3D imaging platform was utilized to capture 3D images of placental villi from different types of diabetes, including type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), and gestational diabetes mellitus (GDM).

RESULTS

Different types of diabetes mellitus exhibit different effects on human placental villous geometric morphological parameters: GDM had greater placenta villous parameters at intermediate villous diameter (IVD), terminal villous diameter (TVD), terminal villous length (TVL) compared to the healthy, T1DM, and T2DM, and these differences were statistically significant. The TVD of T1DM and T2DM had significantly greater sizes than the healthy. There was no statistically significant difference in the number of villous branches among the three types of diabetes, but T1DM and GDM had more villous branches than healthy individuals.

DISCUSSION

Diabetes mellitus affects the geometric morphology of human placental villi, with varying effects observed in pregnancies of different diabetes types. These findings offer a novel avenue for exploring underlying pathophysiological mechanisms and enhancing the management of women with diabetes from preconception through pregnancy.

The role of microRNAs in pregnancies complicated by maternal diabetes

With the global prevalence of diabetes increasing, more people of reproductive age are experiencing hyperglycaemic pregnancies. Maternal Type 1 (T1DM) or Type 2 (T2DM) diabetes mellitus, and gestational diabetes mellitus (GDM) are associated with maternal cardiovascular and metabolic complications. Pregnancies complicated by maternal diabetes also increase the risk of short- and long-term health complications for the offspring, including altered fetal growth and the onset of T2DM and cardiometabolic diseases throughout life. Despite advanced methods for improving maternal glucose control, the prevalence of adverse maternal and offspring outcomes associated with maternal diabetes remains high. The placenta is a key organ at the maternal-fetal interface that regulates fetal growth and development. In pregnancies complicated by maternal diabetes, altered placental development and function has been linked to adverse outcomes in both mother and fetus. Emerging evidence suggests that microRNAs (miRNAs) are key molecules involved in mediating these changes. In this review, we describe the role of miRNAs in normal pregnancy and discuss how miRNA dysregulation in the placenta and maternal circulation is associated with suboptimal placental development and pregnancy outcomes in individuals with maternal diabetes. We also discuss evidence demonstrating that miRNA dysregulation may affect the long-term health of mothers and their offspring. As such, miRNAs are potential candidates as biomarkers and therapeutic targets in diabetic pregnancies at risk of adverse outcomes.

Multifaceted therapeutic approach via thiazolidinedione-infused magnolol in chitosan nanoparticles targeting hyperlipidemia and oxidative stress in gestational diabetes mellitus in experimental mice

Recent advancements in nanotechnology have sparked interest in the synthesis of chitosan nanoparticles and their potential applications in medicine. This study investigates the synthesis of chitosan nanoparticles infused with thiazolidinedione and magnolol (TZ/ML-ChNPs) and their therapeutic effects on gestational diabetes mellitus (GDM) in experimental mice. Using streptozotocin-induced diabetic pregnant mice as a model, the study examines the anti-diabetic effects of TZ/ML-ChNPs in vitro and explores possible mechanisms of action. Results show a notable decrease in α-amylase and α-glucosidase activities in TZ/ML-ChNPs-treated samples. Cytocompatibility and flow cytometry analysis in streptozotocin-induced diabetic pregnant mice conducted on RIN-5F cell line demonstrate the safety profile of TZ/ML-ChNPs. The primary objective of this research is to assess whether TZ/ML-ChNPs can mitigate hyperlipidemia and oxidative stress in diabetic pregnant mice. Chitosan nanoparticles with thiazolidinedione and magnolol have therapeutic effects that may be used in clinical and pharmaceutical applications.

Bone development in fetuses with intrauterine growth restriction caused by maternal endocrine-metabolic dysfunctions

Intrauterine growth restriction (IUGR) affects a large proportion of infants, particularly in underdeveloped countries. Among the main causes of IUGR, maternal endocrine-metabolic dysfunction is highlighted, either due to its high incidence or due to the severity of the immediate and mediated changes that these dysfunctions cause in the fetus and the mother. Although the effects of endocrine and metabolic disorders have been widely researched, there are still no reviews that bring together and summarize the effects of these conditions on bone development in cases of IUGR. Therefore, the present literature review was conducted with the aim of discussing bone changes observed in fetuses with IUGR caused by maternal endocrine-metabolic dysfunction. The main endocrine dysfunctions that occur with IUGR include maternal hyperthyroidism, hypothyroidism, and hypoparathyroidism. Diabetes mellitus, hypertensive disorders, and obesity are the most important maternal metabolic dysfunctions that compromise fetal growth. The bone changes reported in the fetus are, for the most part, due to damage to cell proliferation and differentiation, as well as failures in the synthesis and mineralization of the extracellular matrix, which results in shortening and fragility of the bones. Some maternal dysfunctions, such as hyperthyroidism, have been widely studied, whereas conditions such as hypoparathyroidism and gestational hypertensive disorders require further study regarding the mechanisms underlying the development of bone changes. Similarly, there is a gap in the literature regarding changes related to intramembranous ossification, as most published articles only describe changes in endochondral bone formation associated with IUGR. Furthermore, there is a need for more research aimed at elucidating the late postnatal changes that occur in the skeletons of individuals affected by IUGR and their possible relationships with adult diseases, such as osteoarthritis and osteoporosis.

Lysophosphatidylcholine Impairs the Mitochondria Homeostasis Leading to Trophoblast Dysfunction in Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a common pregnancy disorder associated with an increased risk of pre-eclampsia and macrosomia. Recent research has shown that the buildup of excess lipids within the placental trophoblast impairs mitochondrial function. However, the exact lipids that impact the placental trophoblast and the underlying mechanism remain unclear. GDM cases and healthy controls were recruited at Kaohsiung Medical University Hospital. The placenta and cord blood were taken during birth. Confocal and electron microscopy were utilized to examine the morphology of the placenta and mitochondria. We determined the lipid composition using liquid chromatography-mass spectrometry in data-independent analysis mode (LC/MSE). In vitro studies were carried out on choriocarcinoma cells (JEG3) to investigate the mechanism of trophoblast mitochondrial dysfunction. Results showed that the GDM placenta was distinguished by increased syncytial knots, chorangiosis, lectin-like oxidized low-density lipoprotein (LDL) receptor-1 (LOX-1) overexpression, and mitochondrial dysfunction. Lysophosphatidylcholine (LPC) 16:0 was significantly elevated in the cord blood LDL of GDM patients. In vitro, we demonstrated that LPC dose-dependently disrupts mitochondrial function by increasing reactive oxygen species (ROS) levels and HIF-1α signaling. In conclusion, highly elevated LPC in cord blood plays a pivotal role in GDM, contributing to trophoblast impairment and pregnancy complications.

Effects of multidimensional exercise management on self-efficacy, blood glucose control, and delivery outcomes in pregnant women with gestational diabetes mellitus

Objective

This study aimed to evaluate the effects of multidimensional quantitative exercise management on self-efficacy, blood glucose control, and delivery outcomes in pregnant women with gestational diabetes mellitus (GDM).

Methods

A randomized controlled trial was conducted with 150 pregnant women diagnosed with gestational diabetes mellitus (GDM). Participants were randomly assigned to either the experimental group (Exp), which received a multidimensional quantitative exercise management intervention, or the control group (Con), which received standard GDM management. Results were compared between the groups included self-efficacy scores, blood glucose levels, and delivery outcomes.

Results

Exp group of pregnant women exhibited drastically superior self-efficacy scores as well as more stable blood glucose levels during pregnancy relative to Con group (P < 0.05). Moreover, visual analogue scale (VAS) of pregnant women and Apgar scores of infants in Exp group were considerably better than those in Con group (P < 0.05). In contrast to Con group, pregnant women in Exp group had considerably better labor outcomes along neonatal complication rates (P < 0.05).

Conclusion

Multidimensional quantitative exercise management had a positive impact on pregnant women with GDM. This intervention method can improve self-efficacy levels along better blood glucose control, and enhance delivery outcomes. These findings suggested that multidimensional quantitative exercise management has potential clinical value in the management of GDM, providing an effective management strategy to improve the health conditions of both pregnant women and infants.

Pathophysiology from preconception, during pregnancy, and beyond

Gestational diabetes is the most common medical complication in pregnancy. Historically, gestational diabetes was considered a pregnancy complication involving treatment of rising glycaemia late in the second trimester. However, recent evidence challenges this view. Pre-pregnancy and pregnancy-specific factors influence gestational glycaemia, with open questions regarding roles of non-glycaemic factors in the aetiology and consequences of gestational diabetes. Varying patterns of insulin secretion and resistance in early and late pregnancy underlie a heterogeneity of gestational diabetes in the timing and pathophysiological subtypes with clinical implications: early gestational diabetes and insulin resistant gestational diabetes subtypes are associated with a higher risk of pregnancy complications. Metabolic perturbations of early gestational diabetes can affect early placental development, affecting maternal metabolism and fetal development. Fetal hyperinsulinaemia can affect the development of multiple fetal tissues, with short-term and long-term consequences. Pregnancy complications are prevented by managing glycaemia in early and late pregnancy in some, but not all women with gestational diabetes. A better understanding of the pathophysiology and heterogeneity of gestational diabetes will help to develop novel management approaches with focus on improved prevention of maternal and offspring short-term and long-term complications, from pre-conception, throughout pregnancy, and beyond.

Maternal obesity and metabolic (dysfunction) associated fatty liver disease in pregnancy: a comprehensive narrative review

INTRODUCTION

Obesity and metabolic-associated fatty liver disease (MAFLD) during pregnancy constitute significant problems for routine antenatal care, with increasing prevalence globally. Similar to obesity, MAFLD is associated with a higher risk for maternal complications (e.g. pre-eclampsia and gestational diabetes) and long-term adverse health outcomes for the offspring. However, MAFLD during pregnancy is often under-recognized, with limited management/treatment options.

AREAS COVERED

PubMed/MEDLINE, EMBASE, and Scopus were searched based on a search strategy for obesity and/or MAFLD in pregnancy to identify relevant papers up to 2024. This review summarizes the pertinent evidence on the relationship between maternal obesity and MAFLD during pregnancy. Key mechanisms implicated in the underlying pathophysiology linking obesity and MAFLD during pregnancy (e.g. insulin resistance and dysregulated adipokine secretion) are highlighted. Moreover, a diagnostic approach for MAFLD diagnosis during pregnancy and its complications are presented. Finally, promising relevant areas for future research are covered.

EXPERT OPINION

Research progress regarding maternal obesity, MAFLD, and their impact on maternal and fetal/offspring health is expected to improve the relevant diagnostic methods and lead to novel treatments. Thus, routine practice could apply more personalized management strategies, incorporating individualized algorithms with genetic and/or multi-biomarker profiling to guide prevention, early diagnosis, and treatment.

Clinical value of placental examination for paediatricians

The placenta contains valuable clinical information that is linked to fetal development, neonatal morbidity and mortality, and future health outcomes. Both gross inspection and histopathological examination of the placenta may identify intrinsic or secondary placental lesions, which can contribute directly to adverse neonatal outcomes or indicate the presence of an unfavourable intrauterine environment. Placental examination therefore forms an essential component of the care of high-risk neonates and at perinatal post-mortem examination. In this article, we describe the clinical value of placental examination for paediatricians and perinatal clinicians. We discuss common pathological findings on general inspection of the placenta with photographic examples and provide an overview of the placental pathological examination, including how to interpret key findings. We also address the medico-legal and financial implications of placental examinations and describe current and future clinical considerations for clinicians in regard to placental examination.

First Trimester Placental Biomarkers for Pregnancy Outcomes

The placenta plays a key role in several adverse obstetrical outcomes, such as preeclampsia, intrauterine growth restriction and gestational diabetes mellitus. The early identification of at-risk pregnancies could significantly improve the management, therapy and prognosis of these pregnancies, especially if these at-risk pregnancies are identified in the first trimester. The aim of this review was to summarize the possible biomarkers that can be used to diagnose early placental dysfunction and, consequently, at-risk pregnancies. We divided the biomarkers into proteins and non-proteins. Among the protein biomarkers, some are already used in clinical practice, such as the sFLT1/PLGF ratio or PAPP-A; others are not yet validated, such as HTRA1, Gal-3 and CD93. In the literature, many studies analyzed the role of several protein biomarkers, but their results are contrasting. On the other hand, some non-protein biomarkers, such as miR-125b, miR-518b and miR-628-3p, seem to be linked to an increased risk of complicated pregnancy. Thus, a first trimester heterogeneous biomarkers panel containing protein and non-protein biomarkers may be more appropriate to identify and discriminate several complications that can affect pregnancies.

Study on the regulation of trophoblast activity by abnormally expressed hsa_circ_0024838/miR-543/HIF1A in patients with gestational diabetes mellitus

INTRODUCTION

This study aimed to screen circRNAs involved in gestational diabetes mellitus (GDM)-related macrosomia. One differentially expressed circRNA (DEC), hsa_circ_0024838, was further tested for its potential role and mechanism in trophoblasts.

METHODS

DECs in GDM were selected through GSE182737 and GSE194119. The targets were predicted for DECs and microRNAs (miRNAs), to complete the construction of the circRNA-miRNA-gene network. Functional annotation and related biological pathway enrichment analysis were performed on the target genes of miRNAs in the network. Subsequently, the expression levels of hsa_circ_0024838, miR-543, and HIF1A mRNA were identified by real-time quantitative real-time PCR (RT-qPCR) in GDM patients. Trophoblast activity was assessed via CCK-8 assay, apoptosis assay, and Matrigel invasion assay. Finally, interactions between miR-543 and either hsa_circ_0024838 or HIF1A were confirmed using dual-luciferase reporter assays.

RESULTS

A GDM-related circRNA-miRNA-genes interaction network was constructed, consisting of 35 circRNAs, 46 miRNAs, and 122 target genes. Functional enrichment revealed that the enriched pathways were involved in GDM. Hsa_circ_0024838 and HIF1A mRNA expression levels were upregulated in GDM, while miR-543 expression levels were downregulated. A significant positive correlation between hsa_circ_0024838 and newborn weight was observed. Both hsa_circ_0024838 and HIF1A possessed binding sites for miR-543. Overexpressing hsa_circ_0024838 in high-glucose (HG)-cultured trophoblasts can partially reverse HG-induced reduction in trophoblast cell proliferation/migration and increase apoptosis. But this reversal can be negated by co-transfection with miR-543 mimics. The effects of miR-543 can be counteracted by HIF1A.

DISCUSSION

Hsa_circ_0024838 can regulate the expression of HIF1A by interacting with miR-543. This regulates the HIF1A signaling pathway and enhance vitality in trophoblast cells.

Discrete placental gene expression signatures accompany diabetic disease classifications during pregnancy

BACKGROUND

Gestational diabetes mellitus affects up to 10% of pregnancies and is classified into subtypes gestational diabetes subtype A1 (GDMA1) (managed by lifestyle modifications) and gestational diabetes subtype A2 (GDMA2) (requiring medication). However, whether these subtypes are distinct clinical entities or more reflective of an extended spectrum of normal pregnancy endocrine physiology remains unclear.

OBJECTIVE

Integrated bulk RNA-sequencing (RNA-seq), single-cell RNA-sequencing (scRNA-seq), and spatial transcriptomics harbors the potential to reveal disease gene signatures in subsets of cells and tissue microenvironments. We aimed to combine these high-resolution technologies with rigorous classification of diabetes subtypes in pregnancy. We hypothesized that differences between preexisting type 2 and gestational diabetes subtypes would be associated with altered gene expression profiles in specific placental cell populations.

STUDY DESIGN

In a large case-cohort design, we compared validated cases of GDMA1, GDMA2, and type 2 diabetes mellitus (T2DM) to healthy controls by bulk RNA-seq (n=54). Quantitative analyses with reverse transcription and quantitative PCR of presumptive genes of significant interest were undertaken in an independent and nonoverlapping validation cohort of similarly well-characterized cases and controls (n=122). Additional integrated analyses of term placental single-cell, single-nuclei, and spatial transcriptomics data enabled us to determine the cellular subpopulations and niches that aligned with the GDMA1, GDMA2, and T2DM gene expression signatures at higher resolution and with greater confidence.

RESULTS

Dimensional reduction of the bulk RNA-seq data revealed that the most common source of placental gene expression variation was the diabetic disease subtype. Relative to controls, we found 2052 unique and significantly differentially expressed genes (-22 thresholds; q<0.05 Wald Test) among GDMA1 placental specimens, 267 among GDMA2, and 1520 among T2DM. Several candidate marker genes (chorionic somatomammotropin hormone 1 [CSH1], period circadian regulator 1 [PER1], phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta [PIK3CB], forkhead box O1 [FOXO1], epidermal growth factor receptor [EGFR], interleukin 2 receptor subunit beta [IL2RB], superoxide dismutase 3 [SOD3], dedicator of cytokinesis 5 [DOCK5], suppressor of glucose, and autophagy associated 1 [SOGA1]) were validated in an independent and nonoverlapping validation cohort (q<0.05 Tukey). Functional enrichment revealed the pathways and genes most impacted for each diabetes subtype, and the degree of proximal similarity to other subclassifications. Surprisingly, GDMA1 and T2DM placental signatures were more alike by virtue of increased expression of chromatin remodeling and epigenetic regulation genes, while albumin was the top marker for GDMA2 with increased expression of placental genes in the wound healing pathway. Assessment of these gene signatures in single-cell, single-nuclei, and spatial transcriptomics data revealed high specificity and variability by placental cell and microarchitecture types. For example, at the cellular and spatial (eg, microarchitectural) levels, distinguishing features were observed in extravillous trophoblasts (GDMA1) and macrophages (GDMA2). Lastly, we utilized these data to train and evaluate 4 machine learning models to estimate our confidence in predicting the control or diabetes status of placental transcriptome specimens with no available clinical metadata.

CONCLUSION

Consistent with the distinct association of perinatal outcome risk, placentae from GDMA1, GDMA2, and T2DM-affected pregnancies harbor unique gene signatures that can be further distinguished by altered placental cellular subtypes and microarchitectural niches.

Adipokines in pregnancy

Reproductive success consists of a sequential events chronology, starting with the ovum fertilization, implantation of the embryo, placentation, and cellular processes like proliferation, apoptosis, angiogenesis, endocrinology, or metabolic changes, which taken together finally conduct the birth of healthy offspring. Currently, many factors are known that affect the regulation and proper maintenance of pregnancy in humans, domestic animals, or rodents. Among the determinants of reproductive success should be distinguished: the maternal microenvironment, genes, and proteins as well as numerous pregnancy hormones that regulate the most important processes and ensure organism homeostasis. It is well known that white adipose tissue, as the largest endocrine gland in our body, participates in the synthesis and secretion of numerous hormones belonging to the adipokine family, which also may regulate the course of pregnancy. Unfortunately, overweight and obesity lead to the expansion of adipose tissue in the body, and its excess in both women and animals contributes to changes in the synthesis and release of adipokines, which in turn translates into dramatic changes during pregnancy, including those taking place in the organ that is crucial for the proper progress of pregnancy, i.e. the placenta. In this chapter, we are summarizing the current knowledge about levels of adipokines and their role in the placenta, taking into account the physiological and pathological conditions of pregnancy, e.g. gestational diabetes mellitus, preeclampsia, or intrauterine growth restriction in humans, domestic animals, and rodents.

Childhood atopic disorders in relation to placental changes-A systematic review and meta-analysis

Fetal programming may arise from prenatal exposure and increase the risk of diseases later in life, potentially mediated by the placenta. The objective of this systematic review was to summarize and critically evaluate publications describing associations between human placental changes and risk of atopic disorders during childhood. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The inclusion criteria were original research articles or case reports written in English describing a human placental change in relation to disease occurring in offspring during childhood. The MEDLINE and EMBASE databases were searched for eligible studies. Risk of bias (RoB) was assessed using the ROBINS-I tool. The results were pooled both in a narrative way and by a meta-analysis. Nineteen studies were included (n = 12,997 participants). All studies had an overall serious RoB, and publication bias could not be completely ruled out. However, five studies showed that histological chorioamnionitis in preterm-born children was associated with asthma-related problems (pooled odds ratio = 3.25 (95% confidence interval = 2.22-4.75)). In term-born children, a large placenta (≥750 g) increased the risk of being prescribed anti-asthma medications during the first year of life. Placental histone acetylation, DNA methylation, and gene expression differences were found to be associated with different atopic disorders in term-born children. There is some evidence supporting the idea that the placenta can mediate an increased risk of atopic disorders in children. However, further studies are needed to validate the findings, properly control for confounders, and examine potential mechanisms.

The Placental Role in Gestational Diabetes Mellitus: A Molecular Perspective

During pregnancy, women undergo several metabolic changes to guarantee an adequate supply of glucose to the foetus. These metabolic modifications develop what is known as physiological insulin resistance. When this process is altered, however, gestational diabetes mellitus (GDM) occurs. GDM is a multifactorial disease, and genetic and environmental factors play a crucial role in its aetiopathogenesis. GDM has been linked to both macroscopic and molecular alterations in placental tissues that affect placental physiology. This review summarizes the role of the placenta in the development of GDM from a molecular perspective, including hormonal and pro-inflammatory changes. Inflammation and hormonal imbalance, the characteristics dominating the GDM microenvironment, are responsible for placental changes in size and vascularity, leading to dysregulation in maternal and foetal circulations and to complications in the newborn. In conclusion, since the hormonal mechanisms operating in GDM have not been fully elucidated, more research should be done to improve the quality of life of patients with GDM and their future children.

Placental weight, surface area, shape and thickness - Relations with maternal ethnicity and cardio-metabolic factors during pregnancy

INTRODUCTION

A better understanding of the determinants of placental growth is needed. Our primary aim was to explore associations between maternal ethnic origin and cardio-metabolic factors during pregnancy, and placental weight, surface area, shape and thickness.

METHODS

A multi-ethnic population-based cohort study of 474 pregnant women examined at mean 15 and 28 weeks' gestation. Placentas were inspected after birth by a placental pathologist. Outcome measures were trimmed placental weight and three uncorrelated placental components; surface area, shape (oval vs round) and thickness, created through a principal components analysis. Multivariate linear regression models were used to explore the associations with maternal factors.

RESULTS

Compared with ethnic European women, mothers with South- and East Asian ethnicity had placentas with lower weight (-51 g (95% CI: 75, -27) and -55 g (-95, -14) respectively), primarily due to a smaller surface area. The association between South Asian ethnicity and placental surface area was still significant after adjusting for maternal characteristics and cardio-metabolic factors. Fat mass index in early pregnancy was associated with higher placental weight and thickness. Placental surface area was positively associated with mid-gestational increases in fat mass, fasting glucose and triglycerides and with the 2-h glucose value at the 28 week oral glucose tolerance test, and inversely with a mid-gestational increase in HDL-cholesterol.

DISCUSSION

Mid-gestational changes in fat mass, glucose, triglycerides and cholesterol were associated with, but only partly explained ethnic differences in placental surface area, while maternal fat mass in early pregnancy was associated with placental thickness.

Changes of miR-139-5p, TGFB1, and COL1A1 in the placental tissue of cases with gestational diabetes mellitus

There are structural changes in the placenta of cases with Gestational Diabetes Mellitus (GDM). TGF-β and collagen pathways have crucial roles in tissue remodeling and TGF-β1 and COL1A1 are important genes in these signalling respectively. Also, lncRNA NEAT1, and miRNA hsa-miR-139-5p and hsa-miR-129-5p have regulatory effects on TGF-β1 and COL1A1. Here we aimed to assess their expressions in the placenta tissue of GDM cases. 30 patients with GDM and 30 healthy pregnant women participated in the study. Placental tissues taken during normal or cesarean delivery were used and total RNA was isolated from the tissues. mRNA levels were determined by qPCR and protein levels were determined by ELISA methods. An in silico analysis was done to elucidate the possible relation of TGF-β1 and COL1A1 gene networks with GDM. We determined that NEAT1 and miR-129-5p expression levels did not differ between GDM and healthy control groups (p = 0.697 and 0.412, respectively). But, miR-139-5p mRNA level, TGFB1 and COL1A1 protein levels significantly differ between the GDM and control groups (p = 0.000, p = 0.000 and p = 0.001, respectively). The in silico analysis revealed that TGFB1 and COL1A1 genes network may have important role in the GDM with their variety of members and regulatory molecules NEAT1, hsa-miR-139-5p, and hsa-miR-129-5p can control their functions. The expression of TGFB1, COL1A1 and miR-139-5p is changed in placenta tissue of GDM cases and many genes in the interacting networks of TGFB1 and COL1A1 could contribute to the pathogenicity of GDM.

An overview of diabetes mellitus in pregnant women with obesity

Rates of obesity are increasing world-wide with an estimated 1billion people projected to be obese by 2030 if current trends remain unchanged. Obesity currently considered one of the most significant associated factors of non-communicable diseases poses the greatest threat to health. Diabetes mellitus is an important metabolic disorder closely associated with obesity. It is therefore expected that with the increasing rates of obesity, the rates of diabetes in pregnancy will also be rising. This disorder may pre-date pregnancy (diagnosed or undiagnosed and diagnosed for the first time in pregnancy) or may be of onset in pregnancy. Irrespective of the timing of onset, diabetes in pregnancy is associated with both fetal and maternal complications. Outcomes are much better if control is maximised. Early diagnosis, multidisciplinary care and tailored management with optimum glycaemic control is associated with a significant reduction in not only pregnancy complications but long-term consequences on both the mother and offspring. This review brings together the current understanding of the pathogenesis of the endocrine derangements that are associated with diabetes in pregnancy how screening should be offered and management including pre-pregnancy care and the role of newer agents in management.

Correlation Between Postpartum Myometrial Elasticity and Obstetric Complications in Pregnant Women with Gestational Diabetes Mellitus

Objective

To investigate postpartum myometrial elasticity in pregnant women with gestational diabetes mellitus (GDM) using shear wave elastography (SWE) and analyze the correlation between myometrial SWE values and obstetric complications.

Methods

Clinical data of women who gave birth at Affiliated Hospital of Yangzhou University from August 2022 to July 2023 were retrospectively analyzed and divided into two groups based on GDM diagnosis: the GDM group and the healthy control group. SWE was used to measure the elasticity values of the anterior and posterior myometrial walls in both groups. Differences in placental attachment position and SWE values at the placental attachment site were compared between the two groups. Spearman correlation analysis was utilized to evaluate the correlation between SWE values and obstetric complications.

Results

Glycated hemoglobin (HbA1c), homeostasis model assessment of insulin resistance (HOMA-IR), fasting plasma glucose (FPG), 2-hour postprandial glucose (2h PG), triglycerides (TG), and total cholesterol (TC) levels were higher in the GDM group than in the healthy control group (P<0.05). There was a statistically significant difference in placental attachment position between the two groups (P<0.05). In both the GDM (17.52±0.42 vs 25.29±0.74, P=0.001) and control groups (14.06±5.01 vs 22.20±6.34, P=0.001), mean SWE values were significantly lower for anterior versus posterior placental attachment, and mean SWE values were also significantly higher in the GDM versus control group for both anterior (17.52±0.42 vs 14.06±5.01, P=0.001) and posterior placental attachment (25.29±0.74 vs 22.20±6.34, P=0.001). Spearman correlation analysis showed that postpartum hemorrhage (r=0.632, P=0.017), preeclampsia (r=0.818, P=0.014), premature rupture of membranes (r=0.710, P=0.012), placental abruption (r=0.732, P=0.031), and ketoacidosis (r=0.729, P=0.022) were negatively correlated with average myometrial SWE values in the GDM group (P<0.05).

Conclusion

SWE values at the placental attachment site were higher in GDM patients than in healthy pregnant women, and myometrial elasticity was positively correlated with obstetric complications.

Fetal vascular malperfusion score is linked with developing preeclampsia in women with gestational diabetes mellitus: a retrospective cohort study

OBJECTIVE

Fetal vascular malperfusion is associated with poor perinatal outcomes in women with preeclampsia and gestational diabetes mellitus. The aim of this study was to determine the association between fetal vascular malperfusion score and syncytiotrophoblast basement membrane thickness and clinicopathological variables, such as developing preeclampsia in women with gestational diabetes mellitus.

METHODS

This retrospective cohort study included 65 pregnant participants (34 with gestational diabetes mellitus and 31 controls) between January 2019 and January 2022. Gestational diabetes mellitus was diagnosed as ≥2 of 4 elevated values on a 3-h, 100-g oral glucose tolerance test. The fetal vascular malperfusion score was evaluated by endothelial CD34 positivity in the villous stroma of the placenta. The association between fetal vascular malperfusion score and syncytiotrophoblast basement membrane thickness with clinicopathological variables in women with gestational diabetes mellitus was evaluated.

RESULTS

It was revealed that the gestational diabetes mellitus group had greater fetal vascular malperfusion scores than the control group (gestational diabetes mellitus group fetal vascular malperfusion score: 34.2±9.1 and control group fetal vascular malperfusion score: 26.5±8.7, respectively, p=0.0009). Syncytiotrophoblast basement membrane thickness was correlated with the development of preeclampsia, trophoblast proliferation, and fetal vascular malperfusions (0.3952, p=0.0129; 0.3487, p=0.0211; and 0.4331, p=0.0082, respectively). On the contrary, fetal vascular malperfusions were correlated with the development of preeclampsia, villous edema, and trophoblast proliferation (0.3154, p=0.0343; 0.2922, p=0.4123; and 0.3142, p=0.0355, respectively).

CONCLUSION

The gestational diabetes mellitus group displayed significantly higher fetal vascular malperfusion scores and thickening of the syncytiotrophoblast basement membrane than the control group. There is a correlation between developing preeclampsia and the fetal vascular malperfusion scores and the syncytiotrophoblast basement membrane thickness.

Analysis, validation, and discussion of key genes in placenta of patients with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a common complication during pregnancy, which can have harmful health consequences for both the mother and the fetus. Given the placenta's crucial role as an endocrine organ during pregnancy, exploring and validating key genes in the placenta hold significant potential in the realm of GDM prevention and treatment. In this study, differentially expressed genes (DEGs) were identified from two databases, GSE70493 and PRJNA646212, and verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in placenta tissues. DEGs expression was detected in normal or high-glucose-treated HTR8/SVneo cells. We also investigated the relationship between DEGs and glucose levels in GDM patients. By selecting the intersection of the two databases, we screened 20 DEGs, which were validated in GDM patients. We observed an up-regulation of SLAMF, ALDH1A2, and CHI3L2, and a down-regulation of HLA-E, MYH11, HLA-DRB5, ITGAX, GZMB, NAIP, TMEM74B, RANBP3L, PAEP, WT-1, and CEP170. We conducted further investigations into the expression of DEGs in HTR8/SVneo cells exposed to high glucose, revealing a significant upregulation in the expression of SERPINA3, while the expressions of HLA-E, BCL6, NAIP, PAEP, MUC16, WT-1, and CEP170 were decreased. Moreover, some DEGs were confirmed to have a positive or negative correlation with blood glucose levels of GDM patients through correlation analysis. The identified DEGs are anticipated to exert potential implications in the prevention and management of GDM, thereby offering potential benefits for improving pregnancy outcomes and long-term prognosis of fetuses among individuals affected by GDM.

A review of feto-placental vasculature flow modelling

The placenta provides the vital nutrients and removal of waste products required for fetal growth and development. Understanding and quantifying the differences in structure and function between a normally functioning placenta compared to an abnormal placenta is vital to provide insights into the aetiology and treatment options for fetal growth restriction and other placental disorders. Computational modelling of blood flow in the placenta allows a new understanding of the placental circulation to be obtained. This structured review discusses multiple recent methods for placental vascular model development including analysis of the appearance of the placental vasculature and how placental haemodynamics may be simulated at multiple length scales.

Fatty acids, inflammation and angiogenesis in women with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a metabolic disorder in pregnancy whose prevalence is on the rise. Reports suggest a likely association between inflammation and maternal GDM. A balance between pro and anti-inflammatory cytokines is necessary for the regulation of maternal inflammation system throughout pregnancy. Along with various inflammatory markers, fatty acids also act as pro-inflammatory molecules. However, studies reporting the role of inflammatory markers in GDM are contradictory, suggesting the need of more studies to better understand the role of inflammation in pregnancies complicated by GDM. Inflammatory response can be regulated by angiopoietins suggesting a link between inflammation and angiogenesis. Placental angiogenesis is a normal physiological process which is tightly regulated during pregnancy. Various pro and anti-angiogenic factors influence the regulation of the feto-placental vascular development. Studies evaluating the levels of angiogenic markers in women with GDM are limited and the findings are inconsistent. This review summarizes the available literature on fatty acids, inflammatory markers and angiogenesis in women with GDM. We also discuss the possible link between them and their influence on placental development in GDM.

Metabolic and molecular effects of dietary extra virgin olive oil in blood and placenta of women with GDM

Gestational diabetes mellitus (GDM) increases the risks of maternal, placental, and neonatal complications. Previously, we found that a diet enriched in extra virgin olive oil (EVOO) prevents increased maternal triglyceridemia and placental proinflammatory markers in a cohort of GDM patients. The aim of this work was to evaluate maternal circulating markers of insulin resistance, placental collagen, glycogen and lipid levels, and placental levels of proteins, mRNAs, and a microRNA involved in the endocytic pathway in the same cohort of control women and women with GDM who received or did not receive a diet enriched in EVOO (36 g/day) from weeks 24 to 28 of pregnancy until term.

Results

At term, the TG/HDL cholesterol ratio, fatty acid binding protein 4 circulating levels, and maternal BMI were increased in the GDM patients, alterations prevented by the maternal diet enriched in EVOO. Although there were no changes in placental lipid levels and lipid profile, GDM placentas were thicker than controls and showed increased glycogen and collagen content, alterations prevented by the EVOO enriched diet. GDM placentas showed increases in megalin levels, in the expression of several genes involved in the endocytic pathway, and in miR-199, which targets these genes, alterations prevented by the maternal diet enriched in EVOO.

Conclusions

We identified novel beneficial effects of an EVOO-enriched diet in GDM women, a diet capable of regulating maternal insulin resistance, the structure and metabolism of the placenta, and the placental endocytic pathway, suggesting effects that may be beneficial for fetal development.

Regulation of uterus and placenta remodeling under high estradiol levels in gestational diabetes mellitus models†

The present study aimed to investigate the regulation of placentas and uterus remodeling and involvement of estradiol in gestational diabetes mellitus. To achieve this, we established in vitro and in vivo models for gestational diabetes mellitus placentas by culturing human placental choriocarcinoma cells (BeWo) under hyperglycemic concentration and treating pregnant rats with streptozotocin. We evaluated the expression of angiogenesis-related proteins. The expression of the anti-angiogenic factor, excess placental soluble fms-like tyrosine kinase 1 was increased in our in vitro gestational diabetes mellitus model compared with the control. Moreover, the expressions of placental soluble fms-like tyrosine kinase 1 and the von Willebrand factor were also significantly elevated in the placenta of streptozotocin-treated rats. These data indicate the disruption of angiogenesis in the gestational diabetes mellitus placentas. The expression levels of connexin 43, a component of the gap junction and collagen type I alpha 2 chain, a component of the extracellular matrix, were decreased in the gestational diabetes mellitus uterus. These results suggest that uterus decidualization and placental angiogenesis are inhibited in gestational diabetes mellitus rats. Our results also showed upregulation of the expression of genes regulating estradiol synthesis as well as estrogen receptors in vivo models. Accordingly, the concentration of estradiol measured in the culture medium under hyperglycemic conditions, as well as in the serum and placenta of the streptozotocin-treated rats, was significantly elevated compared with the control groups. These results suggest that the dysregulated remodeling of the placenta and uterus may result in the elevation of estradiol and its signaling pathway in the gestational diabetes mellitus animal model to maintain pregnancy.

Early Prediction of Gestational Diabetes Mellitus Using Placental Strain Elastography and Subcutaneous Adipose Tissue Thickness

AIM

The aim of this study is to investigate the efficacy of placental strain ratio values measured by real-time sonoelastography and maternal subcutaneous adipose tissue thickness measured by two-dimensional ultrasonography in predicting gestational diabetes mellitus in the first trimester.

MATERIALS AND METHODS

The population of the study consisted of the first 210 consecutive singleton pregnant women who applied for routine first-trimester screening between the 11th and 14th week of gestation.B-mode subcutaneous adipose tissue thickness sonography and real-time placental strain elastography scanning were performed.All patients underwent 75 g oral glucose tolerance test between the 24th and 28th week of gestation. American Diabetes Association criteria were used in the diagnosis of gestational diabetes mellitus.

RESULTS

It was observed that body mass index (p<0.001), first-trimester fasting blood sugar (p<0.001), subcutaneous adipose tissue thickness (p<0.001), and placental strain ratio value (p<0.001) affected the development of gestational diabetes mellitus statistically. The multivariate analysis shown that subcutaneous adipose tissue thickness (odds ratio=1.271, 95% CI=1.142-1.416, p<0.001) and placental strain ratio value (odds ratio=3.664, 95% CI=1.927-6.969, p<0.001) were the independent risk factors affecting the development of gestational diabetes mellitus.

CONCLUSIONS

The findings of this study indicated a positive correlation between 75 g oral glucose tolerance test application and first trimester subcutaneous adipose tissue thickness and placental strain ratio. Using the cut-off values of>11.5 mm for subcutaneous adipose tissue and>0.986 for placental strain ratio, the development of gestational diabetes mellitus may be predicted in the early weeks of pregnancy.

Intrauterine Growth Restriction Due to Gestational Diabetes: From Pathophysiology to Diagnosis and Management

Intrauterine growth restriction (IUGR) represents a condition where the fetal weight is less than the 10th percentile for gestational age, or the estimated fetal weight is lower than expected based on gestational age. IUGR can be caused by various factors such as maternal, placental or fetal factors and can lead to various complications for both the fetus and the mother, including fetal distress, stillbirth, preterm delivery, and maternal hypertension. Women with gestational diabetes are at an increased risk of developing IUGR. This article reviews the different aspects of gestational diabetes in addition to IUGR, the diagnostic methods available for IUGR detection, including ultrasound and Doppler studies, discusses the management strategies for women with IUGR and gestational diabetes and analyzes the importance of early detection and timely intervention to improve pregnancy outcomes.

Study on the Regulation of Trophoblast Activity by Abnormally Expressed lncRNA CCDC144NL-AS1 in Patients with Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a common complication in pregnant women. The growth and differentiation of trophoblast cells determine the function of the placenta, and therefore further affect the transport of nutrients to the fetus. lncRNA Coiled-Coil Domain Containing 144 N-Terminal-Like antisense1 (CCDC144NL-AS1) was reported to be abnormally expressed in GDM, but its function and mechanism remain undefined. This study aimed to reveal the expression of CCDC144NL-AS1 in GDM and evaluate its significance in disease development. The expression of CCDC144NL-AS1 in serum and placenta tissues of GDM patients and healthy pregnant women was evaluated using PCR. The effect of CCDC144NL-AS1 on the proliferation, migration, and invasion of trophoblast cells was evaluated with CCK8 and Transwell assay. The mechanism of the interaction between CCDC144NL-AS1 and miR-143-3p was assessed by luciferase reporter assay and cell transfection. CCDC144NL-AS1 was upregulated in GDM patients, which discriminated GDM patients from healthy pregnant women with high sensitivity and specificity and was positively correlated with the insulin resistance indexes. In trophoblast cells, high glucose exposure induced increased CCDC144NL-AS1 and suppressed cell proliferation, migration, and invasion. Silencing CCDC144NL-AS1 could alleviate the inhibitory effect of high glucose, while the knockdown of miR-143-3p reversed the effect of CCDC144NL-AS1. In conclusion, upregulated CCDC144NL-AS1 served as a diagnostic biomarker of GDM and regulated the development of trophoblast cells via negatively modulating miR-143-3p.

Comparative study of microvascular structural changes in the gestational diabetic placenta

AIMS

Microvascular morphology and pathological changes in gestational diabetes mellitus (GDM) placentas and normal placentas were observed via vascular casting technology, electron microscopy, and pathological detection technology. Vascular structure and histological morphology changes in GDM placentas were examined to generate basic experimental data for the diagnosis and prognostic determination of GDM.

METHODS

This case-control study involving 60 placentas, 30 from healthy controls and 30 from patients with GDM. Differences in size, weight, volume, umbilical cord diameter, and gestational age were assessed. Histological changes in the placentas in the two groups were analyzed and compared. A placental vessel casting model was constructed using a self-setting dental powder technique, to compare the two groups. The placental cast microvessels of the two groups were compared using scanning electron microscopy.

RESULTS

There were no significant differences in maternal age or gestational age between the GDM group and the control group (p > .05). The size, weight, volume, and thickness of the placentas in the GDM group were significantly greater than those in the control group, as was umbilical cord diameter (p < .05). Immature villus, fibrinoid necrosis, calcification, and vascular thrombosis were significantly greater in the placental mass in the GDM group (p < .05). The terminal branches of the microvessels in diabetic placenta casts were sparse, with significantly fewer ends and lower villous volume (p < .05).

CONCLUSION

Gestational diabetes can cause gross and histological changes in the placenta, particularly placental microvascular changes.

The effect of phthalates exposure during pregnancy on asthma in infants aged 0 to 36 months: a birth cohort study

This cohort study sought to investigate the effects of phthalates exposure during pregnancy on offspring asthma and its association with placental stress and inflammatory factor mRNA expression levels. A total of 3474 pregnant women from the China Ma'anshan birth cohort participated in this study. Seven phthalate metabolites were detected in urine samples during pregnancy by solid phase extraction-high-performance liquid chromatography tandem mass spectrometry. Placenta stress and inflammation mRNA expression were assessed by real-time quantitative polymerase chain reaction (RT-qPCR). Early pregnancy may be the critical period when phthalates exposure increases the risk of asthma in infants and young children, and there is a certain gender difference in the risk of asthma in infants and young children. Moreover, through the placenta stress and inflammatory factor associated with infant asthma found anti-inflammatory factor of interleukin-10 (IL-10) mRNA expression will reduce the risk of 36-month-old male infant asthma. The expression of interleukin-4(IL-4) and macrophage (M2) biomarker cluster of differentiation 206(CD206) mRNA reduced the risk of asthma in 18-month-old female infants. Placental stress and inflammatory response were analyzed using mediating effects. Tumor necrosis factor-α (TNFα) showed a complete mediating effect between mono-benzyl phthalate (MBzP) exposure in early pregnancy and asthma in 12-month-old males, and IL-10 also showed a complete mediating effect between mono-n-butyl phthalate (MBP) exposure in early and late pregnancy and asthma in 36-month-old males. In summary, exposure to phthalates during pregnancy may contribute to the development of asthma in infants, which may be associated with placental stress and inflammation.

High Glucose Promotes Inflammation and Weakens Placental Defenses against E. coli and S. agalactiae Infection: Protective Role of Insulin and Metformin

Placentas from gestational diabetes mellitus (GDM) patients undergo significant metabolic and immunologic adaptations due to hyperglycemia, which results in an exacerbated synthesis of proinflammatory cytokines and an increased risk for infections. Insulin or metformin are clinically indicated for the treatment of GDM; however, there is limited information about the immunomodulatory activity of these drugs in the human placenta, especially in the context of maternal infections. Our objective was to study the role of insulin and metformin in the placental inflammatory response and innate defense against common etiopathological agents of pregnancy bacterial infections, such as E. coli and S. agalactiae, in a hyperglycemic environment. Term placental explants were cultivated with glucose (10 and 50 mM), insulin (50–500 nM) or metformin (125–500 µM) for 48 h, and then they were challenged with live bacteria (1 × 105 CFU/mL). We evaluated the inflammatory cytokine secretion, beta defensins production, bacterial count and bacterial tissue invasiveness after 4–8 h of infection. Our results showed that a GDM-associated hyperglycemic environment induced an inflammatory response and a decreased beta defensins synthesis unable to restrain bacterial infection. Notably, both insulin and metformin exerted anti-inflammatory effects under hyperglycemic infectious and non-infectious scenarios. Moreover, both drugs fortified placental barrier defenses, resulting in reduced E. coli counts, as well as decreased S. agalactiae and E. coli invasiveness of placental villous trees. Remarkably, the double challenge of high glucose and infection provoked a pathogen-specific attenuated placental inflammatory response in the hyperglycemic condition, mainly denoted by reduced TNF-α and IL-6 secretion after S. agalactiae infection and by IL-1β after E. coli infection. Altogether, these results suggest that metabolically uncontrolled GDM mothers develop diverse immune placental alterations, which may help to explain their increased vulnerability to bacterial pathogens.

Gestational Diabetes Mellitus and Small-for-Gestational-Age: An Insight into the Placental Molecular Biomarkers

Gestational diabetes mellitus (GDM) and small-for-gestational-age (SGA) are two metabolic-related diseases that could affect women during pregnancy. Considering that the chorionic villi (CVs) are crucial structures for the feto-maternal exchange, the alterations in their conformation have been linked to an imbalanced metabolic environment of placenta. In this study, a multidisciplinary approach has been carried out to describe the changes occurring in the placental CVs of GDM and SGA patients. The results revealed higher levels of superoxide dismutase 1 (SOD-1) and catalase (CAT), especially in the GDM placentae, which could be correlated with the hyperglycemic environment characteristic of this pathology. Furthermore, spectroscopy and histologic analyses revealed that both pathologies modify the placental lipid composition altering its structure. However, SGA induces lipid peroxidation and reduces collagen deposition within the CVs. Since the endocannabinoid system (ECS) is involved in placentation and different metabolic activities, the cannabinoid receptor 1 (CB1) and transient receptor potential cation channel subfamily V member 1 (TRPV-1) were analyzed. No changes have been observed either at general or specific levels in the CVs comparing control and pathological samples, suggesting the non-involvement of the cannabinoid system in these two pathologies.

The impact of hyperglycemia upon BeWo trophoblast cell metabolic function: A multi-OMICS and functional metabolic analysis

Pre-existing and gestationally-developed diabetes mellitus have been linked with impairments in placental villous trophoblast cell metabolic function, that are thought to underlie the development of metabolic diseases early in the lives of the exposed offspring. Previous research using placental cell lines and ex vivo trophoblast preparations have highlighted hyperglycemia is an important independent regulator of placental function. However, it is poorly understood if hyperglycemia directly influences aspects of placental metabolic function, including nutrient storage and mitochondrial respiration, that are altered in term diabetic placentae. The current study examined metabolic and mitochondrial function as well as nutrient storage in both undifferentiated cytotrophoblast and differentiated syncytiotrophoblast BeWo cells cultured under hyperglycemia conditions (25 mM glucose) for 72 hours to further characterize the direct impacts of placental hyperglycemic exposure. Hyperglycemic-exposed BeWo trophoblasts displayed increased glycogen and triglyceride nutrient stores, but real-time functional readouts of metabolic enzyme activity and mitochondrial respiratory activity were not altered. However, specific investigation into mitochondrial dynamics highlighted increased expression of markers associated with mitochondrial fission that could indicate high glucose-exposed trophoblasts are transitioning towards mitochondrial dysfunction. To further characterize the impacts of independent hyperglycemia, the current study subsequently utilized a multi-omics approach and evaluated the transcriptomic and metabolomic signatures of BeWo cytotrophoblasts. BeWo cytotrophoblasts exposed to hyperglycemia displayed increased mRNA expression of ACSL1, HSD11B2, RPS6KA5, and LAP3 and reduced mRNA expression of CYP2F1, and HK2, concomitant with increased levels of: lactate, malonate, and riboflavin metabolites. These changes highlighted important underlying alterations to glucose, glutathione, fatty acid, and glucocorticoid metabolism in BeWo trophoblasts exposed to hyperglycemia. Overall, these results demonstrate that hyperglycemia is an important independent regulator of key areas of placental metabolism, nutrient storage, and mitochondrial function, and these data continue to expand our knowledge on mechanisms governing the development of placental dysfunction.

Feto-placental Unit: From Development to Function

The placenta is an intriguing organ that allows us to survive intrauterine life. This essential organ connects both mother and fetus and plays a crucial role in maternal and fetal well-being. This chapter presents an overview of the morphological and functional aspects of human placental development. First, we describe early human placental development and the characterization of the cell types found in the human placenta. Second, the human placenta from the second trimester to the term of gestation is reviewed, focusing on the morphology and specific pathologies that affect the placenta. Finally, we focus on the placenta's primary functions, such as oxygen and nutrient transport, and their importance for placental development.

The new landscape of differentially expression proteins in placenta tissues of gestational diabetes based on iTRAQ proteomics

INTRODUCTION

Gestational diabetes mellitus (GDM) refers to abnormal glucose tolerance that occurs or is firstly diagnosed during pregnancy. GDM is related to various adverse pregnancy outcomes, but GDM pathogeny has not been fully elucidated. Nevertheless, previous studies have observed that many proteins in the placentas of patients with GDM are dysregulated. The present study aimed to establish a novel differentially expressed protein (DEP) landscape of GDM and normal maternal placentas and to explore the possible connection between DEPs and GDM pathogenesis. This study provides new insights into the mechanism of GDM and should make an important contribution to the development of biomarkers.

METHODS

The morphological characteristics of the placenta were observed on 30 GDM and normal maternal placental tissues stained with haematoxylin and eosin. Isobaric tags for relative and absolute quantitation (iTRAQ) was used in the proteomics screening of the DEPs of the normal and GDM maternal placentas. Bioinformatics analysis was performed on the DEPs, and parallel reaction monitoring (PRM) was performed to verify the DEPs. Finally, the quantitative analysis of iTRAQ and PRM was verified by immunohistochemical assay.

RESULTS

A total of 68 DEPs in the GDM placenta were identified with iTRAQ proteomics experiment, comprising 21 up-regulated and 47 down-regulated DEPs. Bioinformatics analysis showed that the regulation of transport, catabolic process of non-coding RNA, cytoskeleton and cell binding were the most abundant Gene Ontology terms, and RNA degradation was an important pathway for significant enrichment. Protein-protein interaction network analysis showed that heterogeneous nuclear ribonucleoproteins A2/B1 (HNRNPA2B1), heterogeneous nuclear ribonucleoprotein A/B (HNRNPAB), heterogeneous nuclear ribonucleoprotein L (HNRNPL) and heterogeneous nuclear ribonucleoprotein A3 (HNRNPA3) were the cores of the up-regulated proteins. Band 3 anion transport protein (SLC4A1), spectrin beta chain erythrocytic (SPTB), ankyrin-1 (ANK1), spectrin beta chain non-erythrocytic 2 (SPTBN2), D-3-phosphoglycerate dehydrogenase (PHGDH) and exosome complex component RRP42 (EXOSC7) were the cores of the down-regulated proteins. These proteins are involved in the binding, splicing, processing, transport and degradation of RNA and in the formation and maintenance of the cytoskeleton. PRM verification results showed that seven proteins, namely, epiplakin (EPPK1), cold-inducible RNA-binding protein (CIRBP), HNRNPA2B1, HNRNPAB, HNRNPL, Ras-related protein Rab-21 (RAB21) and Ras-related protein Rab-3B (RAB3B), were up-regulated, whereas SPTB and SLC4A1 were down-regulated. The results of immunohistochemical assay also showed that the expression of five proteins, namely EPPK1, HNRNPA2B1, HNRNPAB, CIRBP and RAB21, were significantly higher in GDM placental tissues (P < 0.01). The GDM placentas showed changes in the morphological evaluation, including poor villous maturation, obvious increase in the number of syncytiotrophoblast nodules, thickening of the wall of dry villous arterioles with lumen stenosis, increased fibrinous exudation and excessive filling of villous interstitial vessels.

DISCUSSION

Differentially expressed proteins related to a variety of biological processes in the GDM placenta were found. Fourteen proteins, namely, HNRNPA2B1, HNRNPAB, HNRNPL, HNRNPA3, EPPK1, CIRBP, RAB21, RAB3B, SLC4A1, SPTB, ANK1, SPTBN2, PHGDH and EXOSC7, which were differentially expressed in the placenta, may play an important role in regulating the occurrence and development of gestational diabetes through multi-channel and multi-link regulation.

Ameliorative Effects of Bifidobacterium animalis subsp. lactis J-12 on Hyperglycemia in Pregnancy and Pregnancy Outcomes in a High-Fat-Diet/Streptozotocin-Induced Rat Model

Bifidobacterium, a common probiotic, is widely used in the food industry. Hyperglycemia in pregnancy has become a common disease that impairs the health of the mother and can lead to adverse pregnancy outcomes, such as preeclampsia, macrosomia, fetal hyperinsulinemia, and perinatal death. Currently, Bifidobacterium has been shown to have the potential to mitigate glycolipid derangements. Therefore, the use of Bifidobacterium-based probiotics to interfere with hyperglycemia in pregnancy may be a promising therapeutic option. We aimed to determine the potential effects of Bifidobacterium animalis subsp. lactis J-12 (J-12) in high-fat diet (HFD)/streptozotocin (STZ)-induced rats with hyperglycemia in pregnancy (HIP) and respective fetuses. We observed that J-12 or insulin alone failed to significantly improve the fasting blood glucose (FBG) level and oral glucose tolerance; however, combining J-12 and insulin significantly reduced the FBG level during late pregnancy. Moreover, J-12 significantly decreased triglycerides and total cholesterol, relieved insulin and leptin resistance, activated adiponectin, and restored the morphology of the maternal pancreas and hepatic tissue of HIP-induced rats. Notably, J-12 ingestion ameliorated fetal physiological parameters and skeletal abnormalities. HIP-induced cardiac, renal, and hepatic damage in fetuses was significantly alleviated in the J-12-alone intake group, and it downregulated hippocampal mRNA expression of insulin receptor (InsR) and insulin-like growth factor-1 receptor (IGF-1R) and upregulated AKT mRNA on postnatal day 0, indicating that J-12 improved fetal neurological health. Furthermore, placental tissue damage in rats with HIP appeared to be in remission in the J-12 group. Upon exploring specific placental microbiota, we observed that J-12 affected the abundance of nine genera, positively correlating with FBG and leptin in rats and hippocampal mRNA levels of InsR and IGF-1R mRNA in the fetus, while negatively correlating with adiponectin in rats and hippocampal levels of AKT in the fetus. These results suggest that J-12 may affect the development of the fetal central nervous system by mediating placental microbiota via the regulation of maternal-related indicators. J-12 is a promising strategy for improving HIP and pregnancy outcomes.

Identification of human placenta-derived circular RNAs and autophagy related circRNA-miRNA-mRNA regulatory network in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a metabolic and reproductive disease with serious risks and adverse health effects. However, the pathophysiological mechanism of GDM, especially the roles of circRNAs in its pathogenesis, is largely unknown. The objective of this study was to identify and investigate the roles of circRNAs in GDM. In the current study, placental circRNA expression profiles of normal controls and GDM patients were analyzed using high-throughput sequencing. Bioinformatics analysis identified a total of 4,955 circRNAs, of which 37 circRNAs were significantly deregulated in GDM placentas compared with NC placentas. GO and KEGG enrichment analyses demonstrated that metabolic process-associated terms and metabolic pathways that may be related to GDM were significantly enriched. The biological characteristics of placenta-derived circRNAs, such as their stability and RNase R resistance, were also validated Bioinformatics prediction. Moreover, we constructed the autophagy related circRNA-miRNA-mRNA regulatory network and further functional analysis revealed that the circCDH2-miR-33b-3p-ULK1 axis may be associated with autophagy in the placentas of GDM patients. Our study indicates that aberrant expression of circRNAs may play roles in autophagy in GDM placentas, providing new insights into GDM.

Puerariae lobatae Radix Alleviates Pre-Eclampsia by Remodeling Gut Microbiota and Protecting the Gut and Placental Barriers

Pre-eclampsia (PE) is a serious pregnancy complication, and gut dysbiosis is an important cause of it. Puerariae lobatae Radix (PLR) is a medicine and food homologous species; however, its effect on PE is unclear. This study aimed to investigate the efficacy of PLR in alleviating PE and its mechanisms. We used an NG-nitro-L-arginine methyl ester (L-NAME)-induced PE mouse model to examine the efficacy of preventive and therapeutic PLR supplementation. The results showed that both PLR interventions alleviated hypertension and proteinuria, increased fetal and placental weights, and elevated the levels of VEGF and PlGF. Moreover, PLR protected the placenta from oxidative stress via activating the Nrf2/HO-1/NQO1 pathway and mitigated placental damage by increasing intestinal barrier markers (ZO-1, Occludin, and Claudin-1) expression and reducing lipopolysaccharide leakage. Notably, preventive PLR administration corrected gut dysbiosis in PE mice, as evidenced by the increased abundance and positive interactions of beneficial bacteria including Bifidobacterium, Blautia, and Turicibacter. Fecal microbiota transplantation confirmed that the gut microbiota partially mediated the beneficial effects of PLR on PE. Our findings revealed that modulating the gut microbiota is an effective strategy for the treatment of PE and highlighted that PLR might be used as an intestinal nutrient supplement in PE patients.

Effects of glucose and osmotic pressure on the proliferation and cell cycle of human chorionic trophoblast cells

This study investigated the effects of glucose and osmotic pressure on the proliferation and cell cycle of trophoblast cells. HTR8/SVneo cells were treated with 0 (no glucose), 1 (low glucose), 5 (normal), and 25 mmol/L (high glucose) glucose. In addition, the cells were treated with 5 mmol/L glucose (normal) and 5 mmol/L glucose + 20 mmol/L mannitol (mannitol). The cell morphology and proliferation were determined by microscopy and a cell counting kit-8 assay. The cell cycle and apoptosis were examined by flow cytometry. The cell number was relatively decreased and morphological changes were intermediate in the high-glucose group compared with the low-glucose groups. The proportion of cells in the G2/M phase was higher in the low-glucose group than in the other groups, and it was lower in the G1 phase and higher in the S phase in the high-glucose group than in the other groups. Compared with 24 h, cell proliferative activity was restored to a certain extent after 48 h in the high-glucose group. In summary, the blood glucose concentration might influence the proliferation of trophoblast cells. A high-glucose environment inhibited initial cell proliferation, which could be moderately restored after self-regulation. Furthermore, the proliferation of trophoblasts was not affected by the osmotic pressure.

HtrA1 in Gestational Diabetes Mellitus: A Possible Biomarker?

BACKGROUND

The high-temperature requirement A 1 (HtrA1) is a multidomain secretory protein with serine-protease activity, expressed in many tissues, including placenta, where its expression is higher in the first trimester, suggesting an association of this serine protease in early phases of human placenta development. In this study, we evaluated maternal serum HtrA1 levels in the first and third trimester of gestation. In particular, we evaluated a possible role of HtrA1 as an early marker of gestational diabetes mellitus (GDM) in the first trimester of gestation.

METHODS

We evaluated HtrA1 serum levels in the third trimester (36-40 weeks) in normal pregnancies (n = 20) and GDM pregnancies (n = 20) by using ELISA analysis. Secondly, we performed the same analysis by using the first trimester sera (10-12 weeks) of healthy pregnant women that will develop a normal pregnancy (n = 210) or GDM (n = 28) during pregnancy.

RESULTS

We found that HtrA1 serum levels in the third trimester were higher in pregnancies complicated by GDM. Interestingly, higher HtrA1 serum levels were also found in the first trimester in women developing GDM later during the second-third trimester. No significant differences in terms of maternal age and gestational age were found between cases and controls. Women with GDM shown significantly higher pre-pregnancy BMI values compared to controls. Moreover, the probability of GDM occurrence significantly increased with increasing HtrA1 levels and BMI values. The ROC curve showed a good accuracy in predicting GDM, with an AUC of 0.74 (95%CI: 0.64-0.92).

CONCLUSIONS

These results suggest an important role of HtrA1 as an early predictive marker of GDM in the first trimester of gestation, showing a significative clinical relevance for prevention of this disease.

Fetoplacental oxygen homeostasis in pregnancies with maternal diabetes mellitus and obesity

Despite improvements in clinical management, pregnancies complicated by pre-existing diabetes mellitus, gestational diabetes mellitus or obesity carry substantial risks for parent and offspring. Some of the endocrine and metabolic changes in parent and fetus in diabetes mellitus and obesity lead to fetal oxygen deficit, mostly due to insulin-induced accelerated fetal metabolism. The human fetus deals with reduced oxygenation through a wide range of adaptive responses that act at various levels in the placenta as well as the fetus. These responses ensure adequate oxygen delivery to the fetus, increase the oxygen transport capacity of fetal blood and redistribute oxygen-rich blood to vital organs such as the brain and heart. The liver has a central role in adapting to reduced oxygenation by increasing its oxygen extraction and stimulating erythropoietin synthesis to increase haematocrit. The type of adaptive response depends on the onset and duration of hypoxia and the severity of the metabolic disturbance. In pregnancies characterized by diabetes mellitus or obesity, these adaptive systems come under additional strain owing to the increased maternal supply of glucose and resultant fetal hyperinsulinaemia, both of which stimulate oxidative metabolism. In the rare situation that the adaptive responses are overwhelmed, stillbirth can ensue.

Construction of the experimental rat model of gestational diabetes

Objective

Numerous methods for modeling gestational diabetes mellitus (GDM) in rats exist. However, their repeatability and stability are unclear. This study aimed to compare the effects of high-fat and high-sugar (HFHS) diet, HFHS diet combined with streptozotocin (STZ) administration, and HFHS diet combined with movement restriction (MR) modeling methods on rat models to confirm the best method for constructing a rat model of GDM.

Method

Forty female Sprague-Dawley rats were randomly divided into four groups (n = 10): the normal control (NC), HFHS, HFHS+STZ, and HFHS+MR groups. The rats in the NC group were fed with a standard diet, and those in the remaining groups were fed with a HFHS diet. The rats in the HFHS+STZ group received 25 mg/kg STZ on their first day of pregnancy, and those in the HFHS+MR group were subjected to MR during pregnancy. Bodyweight, food intake, water intake, fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR), homeostasis model assessment of insulin sensitivity (HOMA-IS), homeostasis model assessment of β-cell function, pancreatic and placental morphology, and the expression levels of glucose transporter 1 (GLUT1) and glucose transporter 3 (GLUT3) in placentas were then quantified. Moreover, iTRAQ was used to identify placental proteomics.

Results

During pregnancy, the rats in the HFHS+STZ group showed FBG levels that were kept stable in a state of moderate hyperglycemia; the typical GDM symptoms of polydipsia, polyphagia, polyuria, and increased body weight; and the modeling rate of 87.5%. On the first and 19th days of pregnancy, the rats in the HFHS group showed higher FBG than that of the NC group, increasing body weight and food intake and the modeling rate of 50%. On the 19th day of pregnancy, the FBG of the rats in the HFHS+MR group was higher than that of the rats in the NC group, and the modeling rate of 42.9%. Comparison with the NC group revealed that the three modeling groups exhibited increased FINS and HOMA-IR, decreased HOMA-IS, and different degrees of pathological changes in pancreases and placentas. Among the groups, the HFHS+STZ group displayed the greatest changes with significant reductions in the numbers of pancreatic and placental cells and appeared cavitation. The expression levels of GLUT1 and GLUT3 in the placentas of the HFHS+STZ and HFHS+MR groups were higher than those in the placentas of the NC and HFHS groups. The above results indicated that the rats in the HFHS+STZ group showed the best performance in terms of modeling indicators. After the changes in placental proteomics in the HFHS+STZ group were compared with those in the NC group, we found that in the HFHS+STZ group, five proteins were up-regulated and 18 were down-regulated; these proteins were enriched in estrogen signaling pathways.

Conclusion

HFHS combined with the intraperitoneal injection of 25 mg/kg STZ was the best modeling method for the nonspontaneous model of experimentally induced GDM, and its modeling rate was high. The pathological characteristics of the constructed GDM rat model were similar to those of human patients with GDM. Moreover, the model was stable and reliable. The modeling method can provide a basis for constructing a GDM rat model for subsequent research on the prevention and treatment of GDM.

Model application to quantitatively evaluate placental features from ultrasound images with gestational diabetes

PURPOSE

The goal of this study was to introduce PFCnet (placental features classification network), an multimodel model for evaluating and classifying placental features in gestational diabetes mellitus (GDM) and normal late pregnancy. Deep learning algorithms could be utilized to fully automate the examination of alterations in the placenta caused by hyperglycemia.

METHODS

A total of 718 placental ultrasound images, including 139 cases of GDM, were collected, including gray-scale images (GSIs) and microflow images (MFIs). Ultrasonic assessment parameters and perinatal features were recorded. We divided gestational age into two categories for analysis (37 weeks and 37 weeks) based on the cut-off value level of placental maturity. The PFCnet model was introduced for identifying placental characteristics from normal and GDM pregnancies after extensive training and optimization. The model was scored using metrics such as sensitivity, specificity, accuracy, and the area under the curve (AUC).

RESULTS

In view of multimodal fusion (GSIs and MFIs) and deep network optimization training, the overall diagnostic performance of the PFCnet model depending on the region of interest (ROI) was excellent (AUC: 93%), with a sensitivity of 89%, a specificity of 92%, and an accuracy of 92% in the independent test set. The fusion features of GSIs and MFIs in the placenta showed a higher discriminative power than single-mode features (accuracy: Fusion 92% vs. GSIs 84% vs. MFIs 82%). The independent test set at 37 weeks exhibited a better specificity (75% vs. 69%) but a lower sensitivity(95% vs. 100%).

CONCLUSIONS

With its dual channel identification of placental parenchymal and vascular lesions in obstetric complications, the PFCnet classification model has the potential to be a useful tool for detecting placental tissue abnormalities caused by hyperglycemia.

Maternal and Perinatal Risk Factors for Infantile Hemangioma: A Matched Case-Control Study with a Large Sample Size

Introduction

Infantile hemangioma (IH) is the most common benign tumor in infancy, but information about its pathogenesis is limited. The aim of this study was to determine maternal and perinatal risk factors for IH.

Methods

A total of 1033 IH patients were enrolled in the study between 2017 and 2020. IH patients were matched with controls by sex. Trained investigators collected detailed information from the participants. Logistic regression models were used for multivariate analysis.

Results

The statistical analysis demonstrated that miscarriage history (odds ratio [OR] = 4.275; 95% confidence interval [CI] [3.195, 5.720]), anemia in pregnancy (OR = 4.228; 95% CI [3.083, 5.799]), preterm premature rupture of membranes (PPROM) (OR = 3.182; 95% CI [1.359, 7.454]), placenta previa (OR = 2.440; 95% CI [1.787, 3.333]), threatened miscarriage (OR = 2.290; 95% CI [1.726, 3.039]), premature rupture of membranes (PROM) (OR = 1.785; P < 0.05), progesterone use (OR = 1.614; P < 0.001) and abnormal amniotic fluid volume (OR = 1.499; P < 0.05) were independent risk factors for IH. Gestational diabetes mellitus (GDM) (OR = 0.607; 95% CI [0.464, 0.794]), multiple gestations (OR = 0.407; 95% CI [0.232, 0.713]), hypothyroidism (OR = 0.407; 95% CI [0.227, 0.730]) and uterine fibroids (OR = 0.393; 95% CI [0.250, 0.618]) may reduce the risk of IH.

Conclusions

Maternal and perinatal factors are closely associated with IH occurrence. Our study provides reliable clues to guide further exploration of the pathogenesis of IH.

Trial Registration

ClinicalTrials.gov, NCT03331744.

Plain Language Summary

Infantile hemangioma is the most common benign tumor in children, which seriously affects appearance and function and even threatens life. The pathogenesis is not clear, a detailed case-control study of the maternal and perinatal periods with a large sample size will facilitate the development of individualized and precise treatment, early and timely interventions for high-risk children and improvement of prognosis. Our study found that miscarriage history, anemia in pregnancy, preterm premature rupture of membranes (PPROM), placenta previa, threatened miscarriage, premature rupture of membranes (PROM), progesterone use and abnormal amniotic fluid volume were independent risk factors for IH.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-022-00756-4.

The Role of Kisspeptin in the Pathogenesis of Pregnancy Complications: A Narrative Review

Kisspeptins are the family of neuropeptide products of the KISS-1 gene that exert the biological action by binding with the G-protein coupled receptor 54 (GPR54), also known as the KISS-1 receptor. The kisspeptin level dramatically increases during pregnancy, and the placenta is supposed to be its primary source. The role of kisspeptin has already been widely studied in hypogonadotropic hypogonadism, fertility, puberty disorders, and insulin resistance-related conditions, including type 2 diabetes mellitus, polycystic ovary syndrome, and obesity. Gestational diabetes mellitus (GDM), preeclampsia (PE), preterm birth, fetal growth restriction (FGR), or spontaneous abortion affected 2 to 20% of pregnancies worldwide. Their occurrence is associated with numerous short and long-term consequences for mothers and newborns; hence, novel, non-invasive predictors of their development are intensively investigated. The study aims to present a comprehensive review emphasizing the role of kisspeptin in the most common pregnancy-related disorders and neonatal outcomes. The decreased level of kisspeptin is observed in women with GDM, FGR, and a high risk of spontaneous abortion. Nevertheless, there are still many inconsistencies in kisspeptin concentration in pregnancies with preterm birth or PE. Further research is needed to determine the usefulness of kisspeptin as an early marker of gestational and neonatal complications.

The protective effects of S14G-humanin on gestational diabetes mellitus symptoms

Gestational diabetes mellitus is a frequently diagnosed glucose metabolic disorder during pregnancy. Diabetes mellitus has been found to pose important health risks to the developing fetus, mother, and offspring. Here, we investigated the protective effects of S14G-humanin, a potent humanin analogue, against maternal and neonatal adverse outcomes in mice with diabetes mellitus. The results show that S14G-humanin administration reduced the blood glucose levels and elevated the serum insulin levels in diabetes mellitus mice. The parameters of serum lipid metabolism including low-density lipoprotein, total cholesterol, and high-density lipoprotein in diabetes mellitus mice were also decreased after S14G-humanin administration. Intervention with S14G-humanin also increased the fetus alive ratio and fetal length, as well as decreased fetal and placenta weights. In addition, we demonstrate that S14G-humanin elevated the activity of the anti-oxidative enzymes catalase, glutathione peroxidase, and superoxide dismutase and reduced the inflammatory cytokines levels in the placentas of diabetes mellitus mice. The significantly increased endoplasmic reticulum stress in the placentas of diabetes mellitus mice was also attenuated by S14G-humanin administration. Taken together, S14G-humanin exerted protective roles in improving maternal and neonatal outcomes. Our findings indicate that S14G-humanin might be an effective intervention approach for women with diabetes mellitus.

Levels of non-essential trace metals and their impact on placental health: a review

According to recent research, even low levels of environmental chemicals, particularly heavy metals, can considerably disrupt placental homeostasis. This review aims to explore the profile of non-essential trace metals in placental tissues across the globe and to specify trace metal(s) that can be candidates for impaired placental health. Accordingly, we conducted an extensive survey on relevant databases of peer-reviewed papers published in the last two decades. Among a considerable number of non-essential trace metals, arsenic (As), lead (Pb), cadmium (Cd), and mercury (Hg) were identified as the most detrimental to placental health. Comparative analysis showed remarkable differences in placental levels of these trace metals worldwide. Based on current data reported across the globe, a median (min-max) range from 0.55 to 15 ng/g for placental As levels could be deemed safe. The placental Cd and Pb levels were markedly higher in smokers than in non-smokers. Occupationally exposed pregnant women had several orders of magnitude higher Cd, Pb, and Hg levels in placental tissues than non-occupationally exposed women. Also, we concluded that even low-level exposure to As, Cd, Pb, and Hg could be deleterious to proper fetal development. This review implies the need to reduce exposure to non-essential trace metals to preserve placental health and prevent numerous poor pregnancy outcomes. Overall, the information presented is expected to help plan future fundamental and applied investigations on the placental toxicity of As, Cd, Pb, and Hg.