Abnormal Placental Development Research Articles

The Role of Regulatory T Cells and Their Therapeutic Potential in Hypertensive Disease of Pregnancy: A Literature Review.

Hypertensive disorders of pregnancy (HDP), including preeclampsia (PE) and gestational hypertension (GH), are major causes of maternal and foetal morbidity and mortality. This review elucidates the role of regulatory T cells (Tregs) in the immunological aspects of HDP and explores their therapeutic potential. Tregs, which play a critical role in maintaining immune homeostasis, are crucial in pregnancy to prevent immune-mediated rejection of the foetus. The review highlights that Tregs contribute to immunological adaptation in normal pregnancy, ensuring foetal acceptance. In contrast, HDP is associated with Treg dysfunction, which is marked by decreased numbers and impaired regulatory capacity, leading to inadequate immune tolerance and abnormal placental development. This dysfunction is particularly evident in PE, in which Tregs fail to adequately modulate the maternal immune response against foetal antigens, contributing to the pathophysiology of the disorder. Therapeutic interventions aiming to modulate Treg activity represent a promising avenue for HDP management. Studies in animal models and limited clinical trials suggest that enhancing Treg functionality could mitigate HDP symptoms and improve pregnancy outcomes. However, given the multifactorial nature of HDP and the intricate regulatory mechanisms of Tregs, the review explores the complexities of translating in vitro and animal model findings into effective clinical therapies. In conclusion, while the precise role of Tregs in HDP is still being unravelled, their central role in immune regulation during pregnancy is indisputable. Further research is needed to fully understand the mechanisms by which Tregs contribute to HDP and to develop targeted therapies that can safely and effectively harness their regulatory potential for treating hypertensive diseases of pregnancy.

Aberrant methylation of placental development genes in chorionic villi of spontaneous abortions with trisomy 16.

In humans, aneuploidy is incompatible with the birth of healthy children and mainly leads to the death of embryos in the early stages of development in the first trimester of pregnancy. Trisomy 16 is the most common aneuploidy among spontaneous abortions of the first trimester of pregnancy. However, the mechanisms leading to the death of embryos with trisomy 16 remain insufficiently investigated. One of these potential mechanisms is abnormal placental development, including aberrant remodeling of spiral arteries. Spiral artery remodeling involves the migration of trophoblast cells into the maternal spiral arteries, replacing their endothelium and remodeling to ensure a stable embryonic nutrition and oxygen supply. This is a complex process which depends on many factors from both the embryo and the mother. We analyzed the methylation level of seven genes (ADORA2B, NPR3, PRDM1, PSG2, PHTLH, SV2C, and TICAM2) involved in placental development in the chorionic villi of spontaneous abortions with trisomy 16 (n = 14), compared with spontaneous abortions with a normal karyotype (n = 31) and the control group of induced abortions (n = 10). To obtain sequencing libraries, targeted amplification of individual gene regions using designed oligonucleotide primers for bisulfite-converted DNA was used. The analysis was carried out using targeted bisulfite massive parallel sequencing. In the group of spontaneous abortions with trisomy 16, the level of methylation of the PRDM1 and PSG2 genes was significantly increased compared to induced abortions (p = 0.0004 and p = 0.0015, respectively). In the group of spontaneous abortions, there was no increase in the level of methylation of the PRDM1 and PSG2 genes, but the level of methylation of the ADORA2B gene was significantly increased compared to the induced abortions (p = 0.032). The results obtained indicate the potential mechanisms of the pathogenetic effect of trisomy 16 on the placental development with the participation of the studied genes.

Maternal exposure to beta-Cypermethrin disrupts placental development by dysfunction of trophoblast cells from oxidative stress

As a broad-spectrum and efficient insecticide, beta-Cypermethrin (β-CYP) poses a health risk to pregnancy. It matters the mechanisms of maternal exposure to β-CYP for impacting reproductive health. The placenta, a transient organ pivotal for maternal-fetal communication during pregnancy, plays a crucial role in embryonic development. The effect of β-CYP exposure on the placenta and its underlying molecular mechanisms remain obscure. The objective of this study was to investigate the effect of β-CYP exposure on placental development and the function of trophoblast, as well as the underlying mechanisms through CD-1 mouse model (1, 10, 20mg/kg.bw) and in vitro HTR-8/SVneo cell model (12.5, 25, 50, 100μM). We found slower weight gain and reduced uterine wet weight in pregnant mice with maternal exposure to β-CYP during pregnancy, as well as adverse pregnancy outcomes such as uterine bleeding and embryo resorption. The abnormal placental development in response to β-CYP was noticed, including imbalanced placental structure and disrupted labyrinthine vascular development. Trophoblasts, pivotal in placental development and vascular remodeling, displayed abnormal differentiation under β-CYP exposure. This aberration was characterized by thickened trophoblast layers in the labyrinthine zone, accompanied by mitochondrial and endoplasmic reticulum swelling within trophoblasts. Futher researches on human chorionic trophoblast cell lines revealed that β-CYP exposure induced apoptosis in HTR-8/SVneo cells. This induction resulted in a notable decrease in migration and invasion abilities, coupled with oxidative stress and the inhibition of the Notch signaling pathway. N-acetylcysteine (an antioxidant) partially restored the impaired Notch signaling pathway in HTR-8/SVneo cells, and mitigated cellular functional damage attributed to β-CYP exposure. Collectively, exposure to β-CYP induced oxidative stress and then led to inhibition of the Notch signaling pathway and dysfunction of trophoblast cells, ultimately resulted in abnormal placenta and pregnancy. These findings indicate Reactive Oxygen Species as potential intervention targets to mitigate β-CYP toxicity. The comprehensive elucidation contributes to our understanding of β-CYP biosafety and offers an experimental basis for preventing and managing its reproductive toxicity.

Immunohistochemical Investigation of Autophagy in the Uterus during the First Trimester of Pregnancy in Rats

During placental development, autophagy has an important role at the molecular level, especially in cases such as trophoblast cell proliferation and cell death. Abnormal placental development due to trophoblast dysfunction causes serious gynaecological diseases and various fetal malformations. In the study conducted to investigate autophagy on the 5th day of pregnancy, in the pregnant and non pregnant group uterus tissues, uterine glands LC3 and Beclin 1 (+), in the evaluation of myometrium and perimetrium, weak (+) was observed in myometrium cells in pregnancy, while (+) reaction could not be distinguished in perimetrium. In this study, it was concluded that the immunohistochemical increase in LC3 and Beclin 1 intensity in the uterus, especially in the endometrial areas in the first trimester of pregnancy compared to the control group tissues is related to the physiology of pregnancy, homeostasis in pregnancy and hormonal mechanism.

Sonographic Placental Aspects in Fetal Growth Restriction

Fetal growth restriction (FGR) is a complication diagnosed in about 10% of pregnancies and is associated with significant perinatal mortality and morbidity. Both the diagnosis and the correct management of cases of intrauterine growth restriction remain a challenge of modern obstetrics. A normal placental development is essential for a proper intrauterine physical and neurological growth of the fetus throughout pregnancy. Various pathophysiological situations may reflect in abnormal placental development linked with severe pregnancy disorders. In this paper we aim to exemplify sonographic aspects in various placental pathology associated with FGR along with the recommended management. Placental insufficiency is the most common risk factor for FGR and it cannot be directly measured and objectified, remaining a diagnostic of exclusion. The risk for perinatal adverse outcomes in placenta accreta spectrum cases is increased trough the pathological implantation especially in depth. In pregnancies complicated with placental insufficiency, secondary macroscopic lesions can be noted, as parabasal and intervillous thrombosis, hematomas, extensive fibrin deposits and infarcts areas. Even if, over time, multiple studies have targeted methods of preventing intrauterine growth restriction through actions on the mother, the effectiveness of no treatment has been demonstrated.

Gestational exposure to PM2.5 disrupts fetal development by suppressing placental trophoblast syncytialization via progranulin/mTOR signaling

Recent epidemiological and animal studies have indicated that ambient fine particulate matter (PM2.5) exposure during pregnancy is closely associated with intrauterine growth restriction (IUGR). However, the underlying mechanisms remain to be revealed. In this study, we found that gestational exposure to PM2.5 significantly decreased fetal weight and crown-rump length in mice, accompanied by insufficient placental trophoblast syncytialization and increased expression of progranulin (PGRN) in mice placenta. Administering PGRN neutralizing antibody to pregnant mice alleviated growth restriction and insufficient placental trophoblast syncytialization caused by PM2.5, accompanied with suppressed activation of the mTOR signaling pathway. Furthermore, in vitro experiments using human placental BeWo cells showed that 10 μg·mL−1 PM2.5 activated PGRN/mTOR signaling and suppressed forskolin-induced cell fusion, which was blocked by knockdown of PGRN. Taken together, our results demonstrated that PM2.5 exposure during pregnancy inhibited placental trophoblast syncytialization by activating PGRN/mTOR signaling, leading to abnormal placental development and IUGR. This study reveals a novel mechanism underlying the developmental toxicity of PM2.5 exposure during pregnancy.

Current research and evidence gaps on placental development in iron deficiency anemia.

Studying the effects of maternal iron deficiency anemia (IDA) is complex owing to its diverse causes, each independently impacting the placenta and fetus. Simple treatment with iron supplements does not always resolve the anemia. Therefore, delving into how IDA alters placental development at a molecular level is crucial to further optimize treatment. This review addresses the effects of IDA on placental structures and functions, including changes in oxygen levels, blood vessels, and the immune system. Profound understanding of physiological characteristics and regulatory mechanisms of placental development is key to explain the mechanisms of abnormal placental development in pregnancy-associated disorders. In turn, future strategies for the prevention and treatment of pregnancy complications involving the placenta can be devised. These studies are significant for improving human reproductive health, enhancing sociodemographic qualities, and even lifelong wellbeing, a focal point in future placental research.

Epigenetic drug screening for trophoblast syncytialization reveals a novel role for MLL1 in regulating fetoplacental growth.

Abnormal placental development is a significant factor contributing to perinatal morbidity and mortality, affecting approximately 5-7% of pregnant women. Trophoblast syncytialization plays a pivotal role in the establishment and maturation of the placenta, and its dysregulation is closely associated with several pregnancy-related disorders, including preeclampsia and intrauterine growth restriction. However, the underlying mechanisms and genetic determinants of syncytialization are largely unknown. We conducted a systematic drug screen using an epigenetic compound library to systematically investigate the epigenetic mechanism essential for syncytialization, and identified mixed lineage leukemia 1 (MLL1), a histone 3 lysine 4 methyltransferase, as a crucial regulator of trophoblast syncytialization. BeWo cells were utilized to investigate the role of MLL1 during trophoblast syncytialization. RNA sequencing and CUT&Tag were further performed to search for potential target genes and the molecular pathways involved. Human placenta tissue was used to investigate the role of MLL1 in TEA domain transcription factor 4 (TEAD4) expression and the upstream signaling during syncytialization. A mouse model was used to examine whether inhibition of MLL1-mediated H3K4me3 regulated placental TEAD4 expression and fetoplacental growth. Genetic knockdown of MLL1 or pharmacological inhibition of the MLL1 methyltransferase complex (by MI-3454) markedly enhanced syncytialization, while overexpression of MLL1 inhibited forskolin (FSK)-induced syncytiotrophoblast formation. In human placental villous tissue, MLL1 was predominantly localized in the nuclei of cytotrophoblasts. Moreover, a notable upregulation in MLL1 expression was observed in the villus tissue of patients with preeclampsia compared with that in the control group. Based on RNA sequencing and CUT&Tag analyses, depletion of MLL1 inhibited the Hippo signaling pathway by suppressing TEAD4 expression by modulating H3K4me3 levels on the TEAD4 promoter region. TEAD4 overexpression significantly reversed the FSK-induced or MLL1 silencing-mediated trophoblast syncytialization. Additionally, decreased hypoxia-inducible factor 1A (HIF1A) enrichment at the MLL1 promoter was observed during syncytialization. Under hypoxic conditions, HIF1A could bind to and upregulate MLL1, leading to the activation of the MLL1/TEAD4 axis. In vivo studies demonstrated that the administration of MI-3454 significantly enhanced fetal vessel development and increased the thickness of the syncytial layer, thereby supporting fetoplacental growth. These results revealed a novel epigenetic mechanism underlying the progression of syncytialization with MLL1, and suggest potential avenues for identifying new therapeutic targets for pregnancy-related disorders.

The Procoagulant Phospholipid Dependent Clotting Time and the Initiation Phase of Thrombin Generation Test Are Mandatory for the Evaluation of the Risk for Severe Early Onset Preeclampsia

Bakground: Preeclampsia occurs in up to 7% of pregnancies in Western Countries and is a leading cause of maternal and fetal morbidity and mortality. Classification of preeclampsia is based on the timing of symptoms' onset and the severity of the clinical status. Accordingly, early and late preeclampsia are characterized by symptom onset before or after 32-34 weeks of gestation respectively. Pathogenesis of preeclampsia is characterized by abnormal placental vascular development with impaired invasion of the uterine spiral arteries by trophoblasts, resulting in fetal complications and maternal endothelial dysfunction. Intact antithrombotic properties of the endothelial cells and efficient regulation of thrombin generation and platelet activation at the microenvironment of the uterus are necessary conditions for successful trophoblast invasion and development of feto-maternal circulation during normal pregnancy. , Prompt identification of pregnant women at risk of preeclampsia worsening could help to anticipated therapeutic intervention and improvement of the clinical outcome. Aim: The ROADMAP-Early Onset Preeclampsia study (ROADMAP-EOP) aiming to respond to this unmet need assessed the clinical relevance of biomarkers of hypercoagulability and endothelial activation for prompt identification of pregnant women at high risk of preeclampsia. Materials and Methods: An observational single center retrospective case-control study was conducted in pregnant women diagnosed with preeclampsia from July 2020 to July 2021. Pregnant women were retrospectively enrolled upon EOP diagnosis and stratified in mild EOP group (n=34) and severe EOP group (n=15 according to the criteria of the International Society for the Study of Hypertension in Pregnancy ). Eligible women were included in the study before initiation of any treatment for preeclampsia. The control group (n=35) consisted of women with uncomplicated pregnancy. All women were assessed with thromboelastometry, Calibrated Automated Thrombo-gram®, tissue factor activity (TFa), Procoagulant phospholipid dependent clotting time (Procoag-PPL), Proteins S, TFPI, D-dimer, antithrombin, thrombomodulin, fibrinogen prothrombin time and activated partial thromboplastin time. Primary and secondary end points were severe EOP and EOP respectively. Principal component analysis (PCA) was performed to check for associations among the biomarkers and the clinical out-come. Results: There were no significant differences regarding age, gravidity, gestational age and the body mass index (BMI) between EOP groups and normal pregnancy as well as within the EOP groups. Platelet counts were similar in healthy pregnant women, and mild EOP group, and significantly lower in severe EOP (p<0.05). No other statistically significant differences were found between-groups. The PCA showed that the repartition of data allowed to discriminate the patients with EOP from healthy pregnant women as well as patients with mild EPO from those with severe EOP. When biomarkers of hypercoagulability were considered according to the severity of EOP in PCA analysis the lag-time and PPL clotting time were independently associated with the risk of severe EOP (Table 1and Figure 1)). The increase of the lag-time by 1 min was associated with a 20.2-fold increase of the risk of severe EOP. The marginal effects curve shows that for a lag-time longer than 2.6 min, the probability of severe EOP was higher than 50% .Longer Procoag-PPL clotting time was associated with lower risk of severe EOP. The marginal effects curve, showed that for Procoag-PPL clotting time longer than 58.75 sec the probability of severe EOP decreased by 50%. These data suggest that a biological score composed of the Procoag-PPL® clotting time and thrombin generation (Throbmogram-Thrombinoscope® PPP-reagent 1 pM-TF as-say) could be a useful tool to identify pregnant women with high probability of EOP Conclusion: the Procoag-PPL® clotting time and thrombin generation assay reflect cellular derived hypercoagulability and allow accurate screening of pregnant women for the prompt identification of those at risk of EOP and the evaluation of its severity. This concept has to be validated in a large prospective cohort trial. . An external validation of the proposed methodology needs to be performed in a large prospective observational study.

Nanotechnological approaches for the treatment of placental dysfunction: recent trends and future perspectives.

The transitory placenta develops during pregnancy and mediates the blood flow between the mother and the developing baby. Placental dysfunction, including but not limited to placenta accreta spectrum, fetal growth restriction, preeclampsia and gestational trophoblastic disease, arises from abnormal placental development and can result in significant adverse maternal and fetal health outcomes. Unfortunately, there is a lack of treatment alternatives for these disorders. Nanocarriers offer versatility, including extended circulation, organ-specific targetingand intracellular transport, finely tuning therapeutic placental interactions. This thorough review explores nanotechnological strategies for addressing placental disorders, encompassing dysfunction insights, potential drug-delivery targets and recent strides in placenta-targeted nanoparticle (NP) therapies, instilling hope for effective placental malfunction treatment.

Controlling Trophoblast Cell Fusion in the Human Placenta-Transcriptional Regulation of Suppressyn, an Endogenous Inhibitor of Syncytin-1.

Cell fusion in the placenta is tightly regulated. Suppressyn is a human placental endogenous retroviral protein that inhibits the profusogenic activities of another well-described endogenous retroviral protein, syncytin-1. In this study, we aimed to elucidate the mechanisms underlying suppressyn's placenta-specific expression. We identified the promoter region and a novel enhancer region for the gene encoding suppressyn, ERVH48-1, and examined their regulation via DNA methylation and their responses to changes in the oxygen concentration. Like other endogenous retroviral genes, the ERVH48-1 promoter sequence is found within a characteristic retroviral 5' LTR sequence. The novel enhancer sequence we describe here is downstream of this LTR sequence (designated EIEs: ERV internal enhancer sequence) and governs placental expression. The placenta-specific expression of ERVH48-1 is tightly controlled by DNA methylation and further regulated by oxygen concentration-dependent, hypoxia-induced transcription factors (HIF1α and HIF2α). Our findings highlight the involvement of (1) tissue specificity through DNA methylation, (2) expression specificity through placenta-specific enhancer regions, and (3) the regulation of suppressyn expression in differing oxygen conditions by HIF1α and HIF2α. We suggest that these regulatory mechanisms are central to normal and abnormal placental development, including the development of disorders of pregnancy involving altered oxygenation, such as preeclampsia, pregnancy-induced hypertension, and fetal growth restriction.

STUDY OF DETERMINANTS OF PERSISTENT POSTPARTUM HYPERTENSION AT 6 W IN WOMEN WITH PRE-ECLAMPSIA

Objective: Pre-eclampsia is a pregnancy disorder with hypertension and proteinuria. Abnormal placental development and maternal/fetal genetic factors contribute to its pathogenesis. Women with pre-eclampsia are at higher risk of chronic hypertension, emphasizing the importance of postnatal monitoring and preventive measures.
 Methods: The study was conducted at the Department of Obstetrics and Gynaecology, Lady Hardinge Medical College and Smt. Sucheta Kriplani Hospital, New Delhi, from November 2017 to March 2019. Ethical clearance and informed consent were obtained. A total of 150 consecutive women with pre-eclampsia were included. Detailed history, clinical examination, and investigations were conducted. Women were followed until discharge and at 6 w postpartum. Determinants of persistent postpartum hypertension were compared between two groups, and statistical analysis was performed.
 Results: This study aimed to investigate the clinical and biochemical determinants of persistent postpartum hypertension at 6 w in women with pre-eclampsia. A total of 125 out of 150 eligible women with pre-eclampsia were followed up at 6 w postpartum. Socio-demographic, clinical, obstetrical, and treatment-related parameters were analyzed, and logistic regression. A p-value of <0.05 was considered significant.
 Conclusion: In conclusion, parity and previous history of hypertension consistently emerge as risk factors for persistent postpartum hypertension in women with pre-eclampsia, variations in the literature call for further research to reconcile discrepancies and enhance understanding.

Involvement of metalloproteinase and nitric oxide synthase/nitric oxide mechanisms in early decidual angiogenesis-vascularization of normal and experimental pathological mouse placenta related to maternal alcohol exposure.

Successful pregnancy for optimal fetal growth requires adequate early angiogenesis and remodeling of decidual spiral arterioles during placentation. Prior to the initiation of invasion and endothelial replacement by trophoblasts, interactions between decidual stromal cells and maternal leukocytes, such as uterine natural killer cells and macrophages, play crucial roles in the processes of early maternal vascularization, such as proliferation, apoptosis, migration, differentiation, and matrix and vessel remodeling. These placental angiogenic events are highly dependent on the coordination of several mechanisms at the early maternal-fetal interface, and one of them is the expression and activity of matrix metalloproteinases (MMPs) and endothelial nitric oxide synthases (NOSs). Inadequate balances of MMPs and nitric oxide (NO) are involved in several placentopathies and pregnancy complications. Since alcohol consumption during gestation can affect fetal growth associated with abnormal placental development, recently, we showed, in a mouse model, that perigestational alcohol consumption up to organogenesis induces fetal malformations related to deficient growth and vascular morphogenesis of the placenta at term. In this review, we summarize the current knowledge of the early processes of maternal vascularization that lead to the formation of the definitive placenta and the roles of angiogenic MMP and NOS/NO mechanisms during normal and altered early gestation in mice. Then, we propose hypothetical defective decidual cellular and MMP and NOS/NO mechanisms involved in abnormal decidual vascularization induced by perigestational alcohol consumption in an experimental mouse model. This review highlights the important roles of decidual cells and their MMP and NOS balances in the physiological and pathophysiological early maternal angiogenesis-vascularization during placentation in mice.

Nitroxide-HMP-Protects Human Trophoblast HTR-8/SVneo Cells from H2O2-Induced Oxidative Stress by Reducing the HIF1A Signaling Pathway.

Preeclampsia (PE) is a pregnancy-specific syndrome affecting 5-7% of patients. There is no effective treatment available. Early abnormal placental development is associated with oxidative stress (OS) and a release of reactive oxygen species (ROS) in the placenta. This phenomenon leads to downstream signaling, Hypoxia Inducible Factor 1A (HIF1A) stabilization and transcription of the anti-angiogenic factors soluble fms-like tyrosine kinase 1 (sFLT1) and soluble endoglin (sEng), which are known to cause endothelial and trophoblast dysfunction and cardinal features of PE: hypertension, proteinuria and, in severe cases, eclampsia. We tested whether 3-(Hydroxymethyl)-1-oxy-2,2,5,5-tetramethylpyrrolidine (HMP)-a nitroxide-type antioxidant molecule-can reduce placental OS and mitigate PE symptoms in vitro. We induced OS in human trophoblast (HTR-8/SVneo) cells with hydrogen peroxide (H2O2) and assessed whether modulating cell redox function with HMP reduces cell injury, mitochondrial stress and HIF1A and sFLT1 production. Pre-treatment with HMP reduced mitochondrial-derived ROS production, restored LC3B expression and reduced HIF1A and sFLT1 expression in H2O2-exposed HTR-8/SVneo trophoblast cells. HMP improved the mitochondrial electron chain enzyme activity, indicating that a reduction in OS alleviates mitochondrial stress and also reduces anti-angiogenic responses. In reducing placental trophoblast OS, HMP presents a potential novel therapeutic approach for the treatment of PE. Future investigation is warranted regarding the in vivo use of HMP.

Nicotine exposure disrupts placental development via the Notch signaling pathway.

Normal gene expression during early embryonic development and in the placenta is crucial for a successful pregnancy. Nicotine can disrupt normal gene expression during development, leading to abnormal embryonic and placental development. Nicotine is a common indoor air pollutant that is present in cigarette fumes. Due to its lipophilic nature, nicotine can rapidly transport through membrane barriers and spread throughout the body, which can lead to the development of diseases. However, the impact of nicotine exposure during early embryonic development on subsequent development remains elusive. In this study, we found that nicotine significantly elevated reactive oxygen species, DNA damage and cell apoptosis levels with the decrease of blastocyst formation during early embryonic development. More importantly, nicotine exposure during early embryonic development increased placental weight and disrupted placental structure. In molecular level, we also observed that nicotine exposure could specifically cause the hypermethylation of Phlda2 promoter (a maternally expressed imprinted gene associated with placental development) and reduce the mRNA expression of Phlda2. By RNA sequencing analysis, we demonstrated that nicotine exposure affected the gene expression and excessive activation of the Notch signaling pathway thereby affecting placental development. Blocking the Notch signaling pathway by DAPT treatment could recover abnormal placental weight and structure induced by nicotine exposure. Taken together, this study indicates that nicotine causes the declining quality of early embryos and leads to placental abnormalities related to over-activation of the Notch signaling pathway.

Programmed frozen embryo transfer cycles are associated with a higher risk of abnormal placental development: a retrospective cohort study of singleton live births.

Abnormal placental development can lead to adverse outcomes for both mother and fetus. The effect of different types of endometrium preparation regimens of frozen-thawed cycles on the placental development features associated with the perinatal outcomes remains unclear. Hence, we conducted a retrospective cohort study to assess the impact of specific endometrial preparation regimens on placenta-mediated pregnancy complications in singleton live births. A retrospective cohort study was conducted evaluating data of all singleton live births both conceived naturally or by in vitro fertilization (IVF) therapy from 2018 to 2020 at our hospital. Two exposed groups of frozen-thawed embryo transfer (FET) were created by the endometrium preparation regimen as the modified natural cycles (mNC) and the programmed cycles. The nonexposed group was the singleton pregnancies conceived naturally. The obstetrical and perinatal outcomes were compared among the three groups using multivariate analysis to adjust the results for determinants potentially associated with the abnormal placental development. A total of 2186 pregnant women with singleton live births were included in our final analysis and were divided into three groups as naturally conceived group (n=1334), mNC-FETs group (n=217) and programmed-FETs group(n=635). After adjusting for maternal age and parity, no significant difference was observed on the risk of placental disorders between mNC-FET cycles and natural conceived pregnancies (aOR 1.16; 95%CI 1.31-7.01), while programmed-FET cycles were associated with a higher occurrence of placental disorders (aOR 5.36; 95%CI 3.63-8.05). Using the mNC-FET group as a reference and adjusting for confounders such as maternal age, parity, endometrial thickness, and number of embryos transferred, we found that the main manifestation of abnormal placentation in programmed FET cycles was abnormal placental attachment, including placental adhesion and placenta increta (aOR 2.50, 95%CI 1.36-4.90). The dysfunction of placentation in programmed-FET cycles was independently associated with the type of infertility, the total dose of Femostone and thinner endometrium. Additionally, placental disorders in the programmed-FET group were associated with higher rate of preeclampsia, postpartum hemorrhage and Cesarean section. Our retrospective study revealed that the programmed-FET has a substantial impact on placental development, resulting in a higher incidence of preeclampsia, postpartum hemorrhage and Cesarean section. These findings have significant implications on clinical decision-making.

Factors related to fetal demise in cases with congenital heart defects

Congenital heart defects are the most common congenital anomaly. Despite the increasing survival of these children, there is still an increased incidence of fetal demise, frequently attributed to cardiac failure. Considering that abnormal placental development has been described in congenital heart disease, our hypothesis is that placental insufficiency may contribute to fetal death in congenital heart disease. This study aimed to assess cases with fetal congenital heart disease and intrauterine demise, and analyze factors that are related to the demise. All congenital heart disease cases diagnosed prenatally during the period January 2002 to January 2021 were selected from the regional prospective congenital heart disease registry, PRECOR. Multiple pregnancies and pregnancies with fetal trisomy 13 or 18, triploidy, and Turner's syndrome were excluded from the analysis, because fetal demise is attributed to the chromosomal abnormality in these cases. Cases were categorized into 4 groups based on the possible cause of fetal death as follows: cardiac failure, additional (genetic) diagnosis, placental insufficiency, and a group in which no cause was found. A separate analysis was performed for isolated congenital heart disease cases. Of the 4806 cases in the PRECOR registry, 112 had fetal demise, of which 43 were excluded from the analysis (13 multiple pregnancies, 30 genetic). Of these, 47.8% were most likely related to cardiac failure, 42.0% to another (genetic) diagnosis, and 10.1% to placental insufficiency. No cases were allocated to the group with an unknown cause. Only 47.8% of the cases had isolated congenital heart disease, and in this group 21.2% was most likely related to placental insufficiency. This study shows that in addition to cardiac failure and other (genetic) diagnoses, placental factors play an important role in fetal demise in congenital heart disease, especially in cases of isolated heart defects. Therefore, these findings support the importance of regular ultrasonographic assessment of fetal growth and placental function in fetal congenital heart disease.

Mouse models of preeclampsia with preexisting comorbidities.

Preeclampsia is a pregnancy-specific condition and a leading cause of maternal and fetal morbidity and mortality. It is thought to occur due to abnormal placental development or dysfunction, because the only known cure is delivery of the placenta. Several clinical risk factors are associated with an increased incidence of preeclampsia including chronic hypertension, diabetes, autoimmune conditions, kidney disease, and obesity. How these comorbidities intersect with preeclamptic etiology, however, is not well understood. This may be due to the limited number of animal models as well as the paucity of studies investigating the impact of these comorbidities. This review examines the current mouse models of chronic hypertension, pregestational diabetes, and obesity that subsequently develop preeclampsia-like symptoms and discusses how closely these models recapitulate the human condition. Finally, we propose an avenue to expand the development of mouse models of preeclampsia superimposed on chronic comorbidities to provide a strong foundation needed for preclinical testing.

Vascular malperfusion and abruption are prevalent in placentas from pregnancies with congenital heart disease and not associated with cardiovascular risk

Congenital heart disease (CHD) in pregnancy is associated with an increased risk of adverse maternal, obstetric, and neonatal outcomes, plausibly through mechanisms involving abnormal placental development and function. This retrospective study aims to elucidate how maternal CHD influences placental health. Demographic and clinical information were collected via electronic medical record review, and placentas underwent histopathological evaluation. Fifty-three singleton pregnancies were included: 35 participants (66%) were classified as lower cardiovascular risk (modified World Health Organization Classification (mWHO) I, II, II-III), and 18 (34%) were classified as higher cardiovascular risk (mWHO III, IV). 12 participants (23%) had a fetus with small for gestational age (SGA). Maternal vascular malperfusion (53%) and placental abruption (11.6%) were common in this cohort, with prevalence above baseline risk. Participants at higher cardiovascular risk had higher rates of SGA (p = 0.04), subchorionic hematomas (p = 0.01) and birth weight:placental weight < 10th percentile (p = 0.04), but did not differ in rates of maternal vascular malperfusion (p = 0.15) compared to those at lower cardiovascular risk. In pregnancies with maternal CHD, SGA and histologic evidence of maternal vascular malperfusion and placental abruption were common, though patients at higher cardiovascular risk did not show evidence of worsened placental health compared to those at lower risk.

Epigenetic analysis in placentas from sickle cell disease patients reveals a hypermethylation profile.

Pregnancy in Sickle Cell Disease (SCD) women is associated to increased risk of clinical and obstetrical complications. Placentas from SCD pregnancies can present increased abnormal findings, which may lead to placental insufficiency, favoring adverse perinatal outcome. These placental abnormalities are well known and reported, however little is known about the molecular mechanisms, such as epigenetics. Thus, our aim was to evaluate the DNA methylation profile in placentas from women with SCD (HbSS and HbSC genotypes), compared to uncomplicated controls (HbAA). We included in this study 11 pregnant women with HbSS, 11 with HbSC and 21 with HbAA genotypes. Illumina Methylation EPIC BeadChip was used to assess the whole placental DNA methylation. Pyrosequencing was used for array data validation and qRT-PCR was applied for gene expression analysis. Our results showed high frequency of hypermethylated CpGs sites in HbSS and HbSC groups with 73.5% and 76.2% respectively, when compared with the control group. Differentially methylated regions (DMRs) also showed an increased hypermethylation status for the HbSS (89%) and HbSC (86%) groups, when compared with the control group methylation data. DMRs were selected for methylation validation (4 DMRs-HbSS and 3 DMRs the HbSC groups) and after analyses three were validated in the HbSS group, and none in the HbSC group. The gene expression analysis showed differential expression for the PTGFR (-2.97-fold) and GPR56 (3.0-fold) genes in the HbSS group, and for the SPOCK1 (-2.40-fold) and ADCY4 (1.80-fold) genes in the HbSC group. Taken together, these data strongly suggest that SCD (HbSS and HbSC genotypes) can alter placental DNA methylation and lead to gene expression changes. These changes possibly contribute to abnormal placental development and could impact in the clinical course, especially for the fetus, possibly leading to increased risk of abortion, fetal growth restriction (FGR), stillbirth, small for gestational age newborns and prematurity.