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Driven by a lack of appropriate human placenta models, recent years have seen the introduction of bioengineered in vitro models to better understand placental health and disease. Thus far, the focus has been on the maternal–foetal barrier. However, there are many other physiologically and pathologically significant aspects of the placenta that would benefit from state-of-the-art bioengineered models, in particular, integrating advanced culture systems with contemporary biological concepts such as organoids. This critical review defines and discusses the key parameters required for the development of physiologically relevant in vitro models of the placenta. Specifically, it highlights the importance of cell type, mechanical forces, and culture microenvironment towards the use of physiologically relevant models to improve the understanding of human placental function and dysfunction. Refereed/Peer-reviewed

Folate is a dietary micronutrient essential to one-carbon metabolism. The World Health Organisation recommends folic acid (FA) supplementation pre-conception and in early pregnancy to reduce the risk of fetal neural tube defects (NTDs). Subsequently, many countries (~92) have mandatory FA fortification policies, as well as recommendations for periconceptional FA supplementation. Mandatory fortification initiatives have been largely successful in reducing the incidence of NTDs. However, humans have limited capacity to incorporate FA into the one-carbon metabolic pathway, resulting in the increasingly ubiquitous presence of circulating unmetabolised folic acid (uFA). Excess FA intake has emerged as a risk factor in gestational diabetes mellitus (GDM). Several other one-carbon metabolism components (vitamin B12, homocysteine and choline-derived betaine) are also closely entwined with GDM risk, suggesting a role for one-carbon metabolism in GDM pathogenesis. There is growing evidence from in vitro and animal studies suggesting a role for excess FA in dysregulation of one-carbon metabolism. Specifically, high levels of FA reduce methylenetetrahydrofolate reductase (MTHFR) activity, dysregulate the balance of thymidylate synthase (TS) and methionine synthase (MTR) activity, and elevate homocysteine. High homocysteine is associated with increased oxidative stress and trophoblast apoptosis and reduced human chorionic gonadotrophin (hCG) secretion and pancreatic β-cell function. While the relationship between high FA, perturbed one-carbon metabolism and GDM pathogenesis is not yet fully understood, here we summarise the current state of knowledge. Given rising rates of GDM, now estimated to be 14% globally, and widespread FA food fortification, further research is urgently needed to elucidate the mechanisms which underpin GDM pathogenesis.

Folic acid (FA) food fortification in Australia has resulted in a higher-than-expected intake of FA during pregnancy. High FA intake is associated with increased insulin resistance and gestational diabetes. We aimed to establish whether maternal one-carbon metabolism and hormones that regulate glucose homeostasis change in healthy pregnancies post-FA food fortification. Circulating folate, B12, homocysteine, prolactin (PRL), human placental lactogen (hPL) and placental growth hormone (GH2) were measured in early pregnancy maternal blood in women with uncomplicated pregnancies prior to (SCOPE: N = 604) and post (STOP: N = 711)-FA food fortification. FA food fortification resulted in 63% higher maternal folate. STOP women had lower hPL (33%) and GH2 (43%) after 10 weeks of gestation, but they had higher PRL (29%) and hPL (28%) after 16 weeks. FA supplementation during pregnancy increased maternal folate and reduced homocysteine but only in the SCOPE group, and it was associated with 54% higher PRL in SCOPE but 28% lower PRL in STOP. FA food fortification increased maternal folate status, but supplements no longer had an effect, thereby calling into question their utility. An altered secretion of hormones that regulate glucose homeostasis in pregnancy could place women post-fortification at an increased risk of insulin resistance and gestational diabetes, particularly for older women and those with obesity.

The abundance of cell-free microRNA (miRNA) has been measured in many body fluids, including blood plasma, which has been proposed as a source with novel, minimally invasive biomarker potential for several diseases. Despite improvements in quantification methods for plasma miRNAs, there is no consensus on optimal reference miRNAs or to what extent haemolysis may affect plasma miRNA content. Here we propose a new method for the detection of haemolysis in miRNA high-throughput sequencing (HTS) data from libraries prepared using human plasma. To establish a miRNA haemolysis signature in plasma we first identified differentially expressed miRNAs between samples with known haemolysis status and selected miRNA with statistically significant higher abundance in our haemolysed group. Given there may be both technical and biological reasons for differential abundance of signature miRNA, and to ensure the method developed here was relevant outside of our specific context, that is women of reproductive age, we tested for significant differences between pregnant and non-pregnant groups. Here we report a novel 20 miRNA signature (miR-106b-3p, miR-140-3p, miR-142-5p, miR-532-5p, miR-17-5p, miR-19b-3p, miR-30c-5p, miR-324-5p, miR-192-5p, miR-660-5p, miR-186-5p, miR-425-5p, miR-25-3p, miR-363-3p, miR-183-5p, miR-451a, miR-182-5p, miR-191-5p, miR-194-5p, miR-20b-5p) that can be used to identify the presence of haemolysis, in silico, in high throughput miRNA sequencing data. Given the potential for haemolysis contamination, we recommend that assay for haemolysis detection become standard pre-analytical practice and provide here a simple method for haemolysis detection.

MotivationThe search for novel microRNA (miRNA) biomarkers in plasma is hampered by haemolysis, the lysis and subsequent release of red blood cell (RBC) contents, including miRNAs, into surrounding fluid. The biomarker potential of miRNAs comes in part from their multi-compartment origin, and the long-lived nature of miRNA transcripts in plasma, giving researchers a functional window for tissues that are otherwise difficult or disadvantageous to sample. The inclusion of RBC derived miRNA transcripts in downstream analysis introduces a source of error that is difficult to identify post hoc and may lead to spurious results. Where access to a physical specimen is not possible, our tool will provide an in silico approach to haemolysis prediction.ResultsWe present DraculR, an interactive Shiny/R application that enables a user to upload microRNA expression data from short read sequencing of human plasma as a raw read counts table and interactively calculate a metric that indicates the degree of haemolysis contamination.Availability and implementationDraculR and its tutorial are freely available from (https://mxhp75.shinyapps.io/shinyVamp/). Code is available from (https://github.com/mxhp75/shinyVamp.git).

The emerging field of circular RNAs (circRNAs) has identified their novel roles in the development and function of many cancers and inspired the interest of many researchers. circRNAs are also found throughout the healthy body, as well as in other pathological states, but while research into the function and abundance of circRNAs has progressed, our overall understanding of these molecules remains primitive. Importantly, recent studies are elucidating new roles for circRNAs in pregnancy, particularly in the placenta. Given that many of the genes responsible for circRNA production in cancer are also highly expressed in the placenta, it is likely that the same genes act in the production of circRNAs in the placenta. Furthermore, placental development can be referred to as ‘controlled cancer’, as it shares many key signalling pathways and hallmarks with tumour growth and metastasis. Hence, the roles of circRNAs in this field are important to study with respect to pregnancy success but also may provide novel insights for cancer progression. This review illuminates the known roles of circRNAs in pregnancy and the placenta, as well as demonstrating differential placental expressions of circRNAs between complicated and uncomplicated pregnancies.

IntroductionGestational diabetes mellitus (GDM) is thought to be associated with cardio-metabolic risk factor development in women and their children during the early postpartum period and early childhood. We hypothesized that these women and their children would exhibit increased abnormal cardio-metabolic risk factors three years after pregnancy.MethodsWomen from the Screening Tests to Predict Poor Outcomes of Pregnancy study were invited to attend a follow-up with the child from their index pregnancy at 3 years postpartum. Women and children were assessed for anthropometric measures and haemodynamic function. Fasting blood samples were obtained from women to assess lipid and glucose status.ResultsA total of 281 woman-child dyads participated in the 3-year follow-up, with 40 women developing GDM during their index pregnancy. Fasting serum insulin was higher in women with GDM in index pregnancy compared to those with an uncomplicated pregnancy. However, this association was mediated by early pregnancy BMI and socioeconomic index (SEI). The rate of metabolic syndrome was higher in the GDM group than the uncomplicated pregnancy group. Maternal GDM was associated with elevated maternal fasting serum triglycerides at 3 years after adjustment for early pregnancy BMI and SEI. Children exposed to GDM in utero had higher waist circumference compared to children born after an uncomplicated pregnancy, but this is mediated the above covariates.ConclusionExposure to GDM is associated with elevated serum triglycerides in women at 3 years postpartum but other cardiometabolic outcomes in women and children appear to be mediated by early pregnancy BMI and SEI.

The human placenta is a rapidly developing transient organ that is key to pregnancy success. Early development of the conceptus occurs in a low oxygen environment before oxygenated maternal blood begins to flow into the placenta at ∼10-12 weeks’ gestation. This process is likely to substantially affect overall placental gene expression. Transcript variability underlying gene expression has yet to be profiled. In this study, accurate transcript expression profiles were identified for 84 human placental chorionic villus tissue samples collected across 6-23 weeks’ gestation. Differential gene expression (DGE), differential transcript expression (DTE) and differential transcript usage (DTU) between 6-10 weeks’ and 11-23 weeks’ gestation groups were assessed. In total, 229 genes had significant DTE yet no significant DGE. Integration of DGE and DTE analyses found that differential expression patterns of individual transcripts were commonly masked upon aggregation to the gene-level. Of the 611 genes that exhibited DTU, 534 had no significant DGE or DTE. The four most significant DTU genes ADAM10, VMP1, GPR126, and ASAH1, were associated with hypoxia-responsive pathways. Transcript usage is a likely regulatory mechanism in early placentation. Identification of functional roles will facilitate new insight in understanding the origins of pregnancy complications.

Certain maternal complications of pregnancy, including hypertensive disorders of pregnancy, gestational diabetes mellitus, birth of a growth restricted infant, idiopathic preterm labour, and placental abruption, are associated with a significantly increased risk of future maternal cardiovascular disease. In Australia, it is relatively unknown how many women with a history of complicated pregnancies are aware of their future cardiovascular disease risk.The aim of this study was to determine what percentage of women attending a cardiovascular disease prevention clinic in South Australia soon after a complicated pregnancy were aware of their increased risk of cardiovascular disease.This prospective observational study included 188 women attending a postpartum prevention clinic between 7th August 2018 and 10th February 2021. These women had experienced a serious maternal complication of pregnancy approximately seven months earlier. Women completed a self-administered health awareness survey immediately prior to their first clinic appointment to assess their awareness of their increased cardiovascular risk.Over two-thirds (69.1 %) of the women were unaware of the association between pregnancy complications and cardiovascular disease, and 6.4 % of the cohort did not realise they had experienced a complicated pregnancy. Almost 10 % of the cohort did not correctly identify the complication/s they had been diagnosed with during pregnancy.Awareness of the association between complications of pregnancy and future cardiovascular disease was low in our cohort of women who had experienced a complication of pregnancy only seven months earlier. This emphasises the need for improved education for and communication with women to assist in implementing preventative care strategies.

Background: Existing evidence on the effects of race and ethnicity on pregnancy outcomes is restricted to individual studies done within specific countries and health systems. We aimed to assess the impact of race and ethnicity on perinatal outcomes in high-income and upper-middle-income countries, and to ascertain whether the magnitude of disparities, if any, varied across geographical regions. Methods: For this individual participant data (IPD) meta-analysis we used data from the International Prediction of Pregnancy Complications (IPPIC) Network of studies on pregnancy complications; the full dataset comprised 94 studies, 53 countries, and 4 539 640 pregnancies. We included studies that reported perinatal outcomes (neonatal death, stillbirth, preterm birth, and small-for-gestational-age babies) in at least two racial or ethnic groups (White, Black, south Asian, Hispanic, or other). For our two-step random-effects IPD meta-analysis, we did multiple imputations for confounder variables (maternal age, BMI, parity, and level of maternal education) selected with a directed acyclic graph. The primary outcomes were neonatal mortality and stillbirth. Secondary outcomes were preterm birth and a small-for-gestational-age baby. We estimated the association of race and ethnicity with perinatal outcomes using a multivariate logistic regression model and reported this association with odds ratios (ORs) and 95% CIs. We also did a subgroup analysis of studies by geographical region. Findings: 51 studies from 20 high-income and upper-middle-income countries, comprising 2 198 655 pregnancies, were eligible for inclusion in this IPD meta-analysis. Neonatal death was twice as likely in babies born to Black women than in babies born to White women (OR 2·00, 95% CI 1·44–2·78), as was stillbirth (2·16, 1·46–3·19), and babies born to Black women were at increased risk of preterm birth (1·65, 1·46–1·88) and being small for gestational age (1·39, 1·13–1·72). Babies of women categorised as Hispanic had a three-times increased risk of neonatal death (OR 3·34, 95% CI 2·77–4·02) than did those born to White women, and those born to south Asian women were at increased risk of preterm birth (OR 1·26, 95% CI 1·07–1·48) and being small for gestational age (1·61, 1·32–1·95). The effects of race and ethnicity on preterm birth and small-for-gestational-age babies did not vary across regions. Interpretation: Globally, among underserved groups, babies born to Black women had consistently poorer perinatal outcomes than White women after adjusting for maternal characteristics, although the risks varied for other groups. The effects of race and ethnicity on adverse perinatal outcomes did not vary by region. Funding: National Institute for Health and Care Research, Wellbeing of Women.

Refereed/Peer-reviewed The search for novel microRNA (miRNA) biomarkers in plasma is hampered by haemolysis, the lysis and subsequent release of red blood cell contents, including miRNAs, into surrounding fluid. The biomarker potential of miRNAs comes in part from their multicompartment origin and the long-lived nature of miRNA transcripts in plasma, giving researchers a functional window for tissues that are otherwise difficult or disadvantageous to sample. The inclusion of red-blood-cell-derived miRNA transcripts in downstream analysis introduces a source of error that is difficult to identify posthoc and may lead to spurious results. Where access to a physical specimen is not possible, our tool will provide an in silico approach to haemolysis prediction. We present DraculR, an interactive Shiny/R application that enables a user to upload miRNA expression data from a short-read sequencing of human plasma as a raw read counts table and interactively calculate a metric that indicates the degree of haemolysis contamination. The code, DraculR web tool and its tutorial are freely available as detailed herein.

Background We aimed to compare risk factors for CVD 10 years postpartum among women who had ≥ 1 compared to no cardio metabolic risk factor in early first pregnancy. Methods Women of the SCOPE (Screening fOr Pregnancy Endpoints) study from Adelaide, South Australia were invited to participate in a cardiovascular risk assessment 10 years after the delivery of the first child. Data from 141 women who completed all the assessments are included in the analyses. Result Compared to women who did not have any cardio metabolic risk factor at 15 ± 1 weeks’ gestation during the first pregnancy, those who had ≥ 1 risk factor were 5.5 times more likely to have metabolic syndrome 10 years postpartum (aOR = 5.5, 95% CI 1.8–17.3, p = 0.004). Women who had ≥ 1cardio metabolic risk factor during the first pregnancy were more likely to be obese (p = 0.001), have high total cholesterol levels (p Conclusion Cardio metabolic risk factors at the booking visit in the first pregnancy may be useful in identifying young women at risk of future CVD.

Matters Arising article, arising from H. Bové et al. Nature Communications https://doi.org/10.1038/s41467-019-11654-3 (2019).

Parturition signals the end of immune tolerance in pregnancy. Term labour is usually a sterile inflammatory process triggered by damage associated molecular patterns (DAMPs) as a consequence of functional progesterone withdrawal. Activation of DAMPs recruits leukocytes and inflammatory cytokine responses in the myometrium, decidua, cervix and fetal membranes. Emerging evidence shows components of the inflammasome are detectable in both maternal decidua and placenta. However, the activation of the placental inflammasome with respect to mode of delivery has not been profiled. Placental chorionic villus samples from women delivering at termviaunassisted vaginal (UV) birth, labouring lower segment caesarean section (LLSCS, emergency caesarean section) and prelabour lower segment caesarean section (PLSCS, elective caesarean section) underwent high throughput RNA sequencing (NextSeq Illumina) and bioinformatic analyses to identify differentially expressed inflammatory (DE) genes. DE genes (IL1RL1,STAT1,STAT2,IL2RB,IL17RE,IL18BP,TNFAIP2,TNFSF10andTNFRSF8), as well as common inflammasome genes (IL1B,IL1R1,IL1R2,IL6,IL18,IL18R1,IL18R1,IL10, andIL33), were targets for further qPCR analyses and Western blotting to quantify protein expression. There was no specific sensor molecule-activated inflammasome which dominated expression when stratified by mode of delivery, implying that multiple inflammasomes may function synergistically during parturition. Whilst placentae from women who had UV births overall expressed pro-inflammatory mediators, placentae from LLSCS births demonstrated a much greater pro-inflammatory response, with additional interplay of pro- and anti-inflammatory mediators. As expected, inflammasome activation was very low in placentae from women who had PLSCS births. Sex-specific differences were also detected. Placentae from male-bearing pregnancies displayed higher inflammasome activation in LLSCS compared with PLSCS, and placentae from female-bearing pregnancies displayed higher inflammasome activation in LLSCS compared with UV. In conclusion, placental inflammasome activation differs with respect to mode of delivery and neonatal sex. Its assessment may identify babies who have been exposed to aberrant inflammation at birth that may compromise their development and long-term health and wellbeing.

Objectives We aimed to assess women’s perceptions on the long-term risks for cardiovascular disease (CVD) after major pregnancy complications. Methods Women who experienced major pregnancy complications and those who experienced uncomplicated pregnancies were invited to participate in a qualitative study. Focus group discussions (FGDs) and self-administered questionnaires were used to explore: The knowledge of long-term sequelae after experiencing a major pregnancy complication; Importance of education on heart health; The practicality of referral to a clinic after pregnancy complications; Willingness for regular postpartum clinic visits after pregnancy complications. A thematic qualitative analysis was undertaken. Results 26 women participated in four FGDs. The majority of women did not know of the association between major pregnancy complications and CVD. The main views expressed were: Women who experience pregnancy complications should receive education on improving heart health; An appointment for the first CVD risk screening visit needs to be made prior to discharge from the delivery suite; Women will benefit by having the option to select between a hospital and a general-practitioner based model of follow up. Conclusions These views are important in developing postpartum strategies to reduce CVD risk among women who experience pregnancy complications.

Background and Aims: A concerning rise in incidence of young-onset cancers globally led to the examination of trends in incidence and survival of gastrointestinal (GI) adenocarcinomas in the Northern Territory (NT), Australia, over a 28-year period, with a special emphasis on Indigenous peoples. Methods: This cross-sectional analysis of a prospective longitudinal database, NT Cancer Registry (1990–2017), includes all reported cases of GI (oesophagus, gastric, small intestinal, pancreas, colon, and rectum) adenocarcinomas. Poisson regression was used to estimate incidence ratio ratios, and survival was modelled using Cox proportional hazard models separately for people aged 18–50 years and >50 years. Results: A total of 1608 cases of GI adenocarcinoma were recorded during the time of the study. While the overall incidence in people 18–50 years remained unchanged over this time (p = 0.51), the rate in individuals aged >50 years decreased (IRR = 0.65 (95% CI 0.56–0.75; p < 0.0001)). Incidence rates were significantly less in females >50 years (IRR = 0.67 95% CI 0.59–0.75; p < 0.0001), and their survival was significantly better (HR = 0.84 (95%CI 0.72–0.98; p < 0.03)) compared to males. Overall survival across all GI subsites improved in both age cohorts, especially between 2010 and 2017 (HR = 0.45 (95%CI 0.29–0.72; p < 0.0007) and HR = 0.64 (95%CI 0.52–0.78; p < 0.0001), respectively) compared to 1990–1999, driven by an improvement in survival in colonic adenocarcinoma alone, as the survival remained unchanged in other GI subsites. The incidence was significantly lower in Indigenous patients compared to non-Indigenous patients, in both age cohorts (18–50 years IRR = 0.68 95% CI 0.51–0.91; p < 0.009 and >50 years IRR = 0.48 95% CI 0.40–0.57; p < 0.0001). However, Indigenous patients had worse survival rates (18–50 years HR = 2.06 95% CI 1.36–3.11; p < 0.0007 and >50 years HR = 1.66 95% CI 1.32–2.08; p < 0.0001). Conclusions: There is a trend towards an increased incidence of young-onset GI adenocarcinomas in the NT. Young Indigenous patients have lower incidence but worse survival across all GI subsites, highlighting significant health inequities in life expectancy. Targeted, culturally safe Indigenous community-focussed programs are needed for early detection and patient-centred management of GI adenocarcinomas.

Simple Summary This study from South Australia using the state’s Cancer Registry data provides compelling evidence for a significant increase in the incidence of young-onset (18–50 years) gastrointestinal (oesophageal, stomach, colon and rectum, and pancreas) adenocarcinomas over the last three decades. The trend observed in the young cohort was not mirrored in older individuals >50 years. This increased incidence, though noted in both sexes, was more pronounced in males compared to females. Survival in the young-onset adenocarcinoma cohort was only seen in patients with colorectal cancers, but not oesophagus, stomach and pancreas. This study calls for a concerted effort aimed at determining the sociodemographic factors underlying this disturbing trend with the aim of developing preventative strategies. Abstract Background & Aims: Globally, there has been a concerning rise in the incidence of young-onset cancers. The aim of this study was to provide trends in the incidence and survival of gastrointestinal adenocarcinomas (oesophagus, stomach, pancreas, and colorectal) in South Australia over a 27-year period. Methods: This is a cross-sectional analysis of a prospective longitudinal database including all cases of gastrointestinal adenocarcinomas prospectively reported to the South Australian (State) Cancer Registry from 1990 to 2017. Results: A total of 28,566 patients diagnosed with oesophageal, stomach, pancreatic, or colorectal adenocarcinoma between 1990 and 2017 were included in the study. While the overall incidence for gastrointestinal adenocarcinomas in individuals >50 years has decreased since 2000 (IRR of 0.97 (95% CI 0.94–1.00; p = 0.06)) compared to 1990–1999, the rate amongst individuals aged 18–50 has significantly increased (IRR 1.41 (95% CI 1.27–1.57; p < 0.001)) during the same reference time period. Although noted in both sexes, the rate of increase in incidence was significantly greater in males (11.5 to 19.7/100,000; p < 0.001). The overall survival from adenocarcinomas across all subsites improved in the >50-year cohort in the last decade (HR 0.89 (95% CI 0.86–0.93; p < 0.001)) compared to 1990–1999. In individuals aged 18–50 years, there has only been a significant improvement in survival for colorectal cancer (HR 0.82 (95% CI 0.68–0.99; p < 0.04)), but not the other subsites. A lower overall survival was noted for males in both age cohorts (18–50 years—HR 1.24 (95% CI 1.09–1.13; p < 0.01) and >50 years—HR 1.13 (95% CI 1.10–1.16; p < 0.001), respectively) compared to females. Conclusions: This study from South Australia demonstrates a significant increase in young-onset gastrointestinal adenocarcinomas over the last 28 years, with a greater increase in the male sex. The only significant improvement in survival in this cohort has been noted in colorectal cancer patients.

The COVID-19 pandemic has infected nearly 178 million people and claimed the lives of over 3.8 million in less than 15 months. This has prompted a flurry of research studies into the mechanisms and effects of SARS-CoV-2 viral infection in humans. However, studies examining the effects of COVID-19 in pregnant women, their placentae and their babies remain limited. Furthermore, reports of safety and efficacy of vaccines for SARS-CoV-2 in pregnancy are limited. This review concisely summarises the case studies and research on COVID-19 in pregnancy, to date. It also reviews the mechanism of infection with SARS-CoV-2, and its reliance and effects upon the renin-angiotensin-aldosterone system. Overall, the data suggest that infection during pregnancy can be dangerous at any time, but this risk to both the mother and fetus, as well as placental damage, increases during the third trimester. The possibility of vertical transmission, which is explored in this review, remains contentious. However, maternal infection with SARS-CoV-2 can increase risk of miscarriage, preterm birth and stillbirth, which is likely due to damage to the placenta.