The ratio of soluble fms-like tyrosine kinase 1 to placental growth factor predicts time to delivery and mode of birth in patients with suspected preeclampsia- a secondary analysis of the INSPIRE trial.

BACKGROUND: The ratio of soluble fms-like tyrosine kinase 1 to placental growth factor (sFLT1/PLGF) is a useful biomarker for preeclampsia. Since it is a measure of placental dysfunction, it could also be a predictor of clinical deterioration and fetal tolerance to intrapartum stress. OBJECTIVES: We tested the hypothesis that sFLT1/PLGF ratio predicts time to delivery. Secondary objectives were to examine associations between the sFLT1/PLGF ratio and mode of birth, fetal distress, need for labor induction and birthweight z-score. STUDY DESIGN: Secondary analysis of the INSPIRE trial, a randomized interventional study on prediction of preeclampsia/eclampsia in which women with suspected preeclampsia were recruited and their blood sFLT1/PLGF ratio was assessed. We stratified participants into three groups according to the ratio result: category 1 (sFLT1/PLGF≤38); category 2 (sFLT1/PLGF>38 and <85); and category 3 (sFLT1/PLGF≥85). We modelled time from sFLT1/PLGF determination to delivery using Kaplan-Meier curves and compared the three ratio categories adjusting for gestational age at sFLT1/PLGF determination and trial arm with Cox Regression. The association between ratio category and mode of delivery, induction of labour and fetal distress was assessed using a multivariable logistic regression adjusting for gestational age at sampling and trial arm. The association between birthweight z-score and sFLT1/PLGF ratio was evaluated using multiple linear regression. Subgroup analysis was conducted in women with no preeclampsia and spontaneous onset of labor; women with preeclampsia; and participants in the non-reveal arm. RESULTS: Higher ratio categories were associated with a shorter latency from sFLT1/PLGF determination to delivery (37 vs 13 vs 10 days for ratios categories 1-3 respectively), hazards ratio for category 3 ratio of 5.64 (95%CI 4.06-7.84, p<0.001). A sFLT/PlGF ratio≥85 had specificity of 92.7%(95%CI 89.0-95.1%) and sensitivity of 54.72% (95% CI, 41.3-69.5) for prediction of preeclampsia indicated delivery within 2 weeks. A ratio category 3 was also associated with decreased odds of spontaneous vaginal delivery (OR 0.47, 95%CI 0.25-0.89); an almost six fold increased risk of emergency cesarean section (OR 5.89, 95%CI 3.05-11.21); and a three-fold increased risk for intrapartum fetal distress requiring operative delivery or cesarean section (OR 3.04, 95%CI 1.53-6.05) when compared to patients with ratios≤38. Higher ratio categories were also associated with higher odds of induction of labor when compared to ratios category 1 (category 2, OR 2.20, 95%CI 1.02-4.76; category 3, OR 6.0, 95%CI 2.01-17.93); and lower median birthweight z-score. Within subgroups of women a)without preeclampsia and with spontaneous onset of labor and b)women with preeclampsia, the log ratio was significantly higher in patients requiring intervention for fetal distress or failure to progress compared to those who delivered vaginaly without intervention. In the subset of women with no preeclampsia and spontaneous onset of labour, those who required intervention for fetal distress or failure to progress had a significantly higher log ratio than those who delivered vaginaly without needing intervention. CONCLUSION: The sFLT1/PLGF ratio might be helpful in risk-stratification of patients who present with suspected preeclampsia regarding clinical deterioration, intrapartum fetal distress and mode of birth (including the need for intervention in labour).

Infection episodes and islet autoantibodies in children at increased risk for type 1 diabetes before and during the COVID-19 pandemic.

OBJECTIVES: To determine the impact of the COVID-19 pandemic on the incidence rates of infection and islet autoimmunity in children at risk for type 1 diabetes. METHODS: 1050 children aged 4 to 7 months with an elevated genetic risk for type 1 diabetes were recruited from Germany, Poland, Sweden, Belgium and the UK. Reported infection episodes and islet autoantibody development were monitored until age 40 months from February 2018 to February 2023. RESULTS: The overall infection rate was 311 (95% Confidence Interval [CI], 304-318) per 100 person years. Infection rates differed by age, country, family history of type 1 diabetes, and period relative to the pandemic. Total infection rates were 321 per 100 person-years (95% CI 304-338) in the pre-pandemic period (until February 2020), 160 (95% CI 148-173) per 100 person-years in the first pandemic year (March 2020-February 2021; P < 0.001) and 337 (95% CI 315-363) per 100 person-years in subsequent years. Similar trends were observed for respiratory and gastrointestinal infections. Islet autoantibody incidence rates were 1.6 (95% CI 1.0-2.4) per 100 person-years in the pre-pandemic period, 1.2 (95% CI 0.8-1.9) per 100 person-years in the first pandemic year (P = 0.46), and 3.4 (95% CI 2.3-4.8) per 100 person-years in subsequent years (P = 0.005 vs. pre-pandemic year; P < 0.001 vs. first pandemic year). CONCLUSIONS: The COVID-19 pandemic was associated with significantly altered infection patterns. Islet autoantibody incidence rates increased two-fold when infection rates returned to pre-pandemic levels.

Vaginal micronised progesterone for the prevention of hypertensive disorders of pregnancy: A systematic review and meta-analysis.

BACKGROUND: Treatment with vaginal progesterone reduces the risk of miscarriage and preterm birth in selected high-risk women. The hypothesis that vaginal progesterone can reduce the risk of hypertensive disorders of pregnancy (HDP) is unexplored. OBJECTIVES: To summarise the evidence on the effectiveness of vaginal progesterone to reduce the risk of HDP. SEARCH STRATEGY: We searched Embase (OVID), MEDLINE (OVID), PubMed, CENTRAL and clinicaltrials.gov from inception until 20 June 2023. SELECTION CRITERIA: We included placebo-controlled randomised trials (RCTs) of vaginal progesterone for the prevention or treatment of any pregnancy complications. DATA COLLECTION AND ANALYSIS: We extracted absolute event numbers for HDP and pre-eclampsia in women receiving vaginal progesterone or placebo, and meta-analysed the data with a random effects model. We appraised the certainty of the evidence using GRADE methodology. MAIN RESULTS: The quantitative synthesis included 11 RCTs, of which three initiated vaginal progesterone in the first trimester, and eight in the second or third trimesters. Vaginal progesterone started in the first trimester of pregnancy lowered the risk of any HDP (risk ratio [RR] 0.71, 95% confidence interval [CI] 0.53-0.93, 2 RCTs, n = 4431 women, I2 = 0%; moderate-certainty evidence) and pre-eclampsia (RR 0.61, 95% CI 0.41-0.92, 3 RCTs, n = 5267 women, I2 = 0%; moderate-certainty evidence) when compared with placebo. Vaginal progesterone started in the second or third trimesters was not associated with a reduction in HDP (RR 1.19, 95% CI 0.67-2.12, 3 RCTs, n = 1602 women, I2 = 9%; low-certainty evidence) or pre-eclampsia (RR 0.97, 95% CI 0.71-1.31, 5 RCTs, n = 4274 women, I2 = 0%; low-certainty evidence). CONCLUSIONS: Our systematic review found first-trimester initiated vaginal micronised progesterone may reduce the risk of HDP and pre-eclampsia.

Protein Profiling of Placental Extracellular Vesicles in Gestational Diabetes Mellitus.

Throughout pregnancy, some degree of insulin resistance is necessary to divert glucose towards the developing foetus. In gestational diabetes mellitus (GDM), insulin resistance is exacerbated in combination with insulin deficiency, causing new-onset maternal hyperglycaemia. The rapid reversal of insulin resistance following delivery strongly implicates the placenta in GDM pathogenesis. In this case-control study, we investigated the proteomic cargo of human syncytiotrophoblast-derived extracellular vesicles (STBEVs), which facilitate maternal-fetal signalling during pregnancy, in a UK-based cohort comprising patients with a gestational age of 38-40 weeks. Medium/large (m/l) and small (s) STBEVs were isolated from GDM (n = 4) and normal (n = 5) placentae using ex vivo dual-lobe perfusion and subjected to mass spectrometry. Bioinformatics were used to identify differentially carried proteins and mechanistic pathways. In m/lSTBEVs, 56 proteins were differently expressed while in sSTBEVs, no proteins reached statistical difference. Differences were also observed in the proteomic cargo between m/lSTBEVs and sSTBEVs, indicating that the two subtypes of STBEVs may have divergent modes of action and downstream effects. In silico functional enrichment analysis of differentially expressed proteins in m/lSTBEVs from GDM and normal pregnancy found positive regulation of cytoskeleton organisation as the most significantly enriched biological process. This work presents the first comparison of two populations of STBEVs' protein cargos (m/l and sSTBEVs) from GDM and normal pregnancy isolated using placenta perfusion. Further investigation of differentially expressed proteins may contribute to an understanding of GDM pathogenesis and the development of novel diagnostic and therapeutic tools.

Respiratory Syncytial Virus Vaccination during Pregnancy and Effects in Infants.

BACKGROUND: Respiratory syncytial virus (RSV) is the dominant cause of severe lower respiratory tract infection in infants, with the most severe cases concentrated among younger infants. METHODS: Healthy pregnant women, at 28 weeks 0 days through 36 weeks 0 days of gestation, with an expected delivery date near the start of the RSV season, were randomly assigned in an overall ratio of approximately 2:1 to receive a single intramuscular dose of RSV fusion (F) protein nanoparticle vaccine or placebo. Infants were followed for 180 days to assess outcomes related to lower respiratory tract infection and for 364 days to assess safety. The primary end point was RSV-associated, medically significant lower respiratory tract infection up to 90 days of life, and the primary analysis of vaccine efficacy against the primary end point was performed in the per-protocol population of infants (prespecified criterion for success, lower bound of the 97.52% confidence interval [CI] of ≥30%). RESULTS: A total of 4636 women underwent randomization, and there were 4579 live births. During the first 90 days of life, the percentage of infants with RSV-associated, medically significant lower respiratory tract infection was 1.5% in the vaccine group and 2.4% in the placebo group (vaccine efficacy, 39.4%; 97.52% CI, -1.0 to 63.7; 95% CI, 5.3 to 61.2). The corresponding percentages for RSV-associated lower respiratory tract infection with severe hypoxemia were 0.5% and 1.0% (vaccine efficacy, 48.3%; 95% CI, -8.2 to 75.3), and the percentages for hospitalization for RSV-associated lower respiratory tract infection were 2.1% and 3.7% (vaccine efficacy, 44.4%; 95% CI, 19.6 to 61.5). Local injection-site reactions among the women were more common with vaccine than with placebo (40.7% vs. 9.9%), but the percentages of participants who had other adverse events were similar in the two groups. CONCLUSIONS: RSV F protein nanoparticle vaccination in pregnant women did not meet the prespecified success criterion for efficacy against RSV-associated, medically significant lower respiratory tract infection in infants up to 90 days of life. The suggestion of a possible benefit with respect to other end-point events involving RSV-associated respiratory disease in infants warrants further study. (Funded by Novavax and the Bill and Melinda Gates Foundation; ClinicalTrials.gov NCT02624947.).

Placental capillary pericytes release excess extracellular vesicles under hypoxic conditions inducing a pro-angiogenic profile in term pregnancy.

Pericytes are multifunctional cells wrapped around capillary endothelia, essential for vascular health, development, and blood flow regulation, although their role in human placental chorionic villi has not been fully explored. The second half of normal pregnancy is characterized by a progressive decline in placental and fetal oxygen levels which, by term, comprises a substantial degree of hypoxia. We hypothesized this hypoxia would stimulate pericyte regulation of chorionic villous capillary function. This study's objective was to investigate the role of hypoxia on normal term placental pericytes (PLVP) and their signaling to endothelial cells. First, we confirmed fetoplacental hypoxia at term by a new analysis of umbilical arterial blood oxygen tension of 3,010 healthy singleton neonates sampled at caesarean section and before labor. We then measured the release of cytokines, chemokines, and small extracellular vesicles (PLVPsv), from PLVP cultured at 20%, 8% and 1% O2. As O2 levels decreased, secreted cytokines and chemokines [interleukin-6 (IL-6), interleukin-1α (IL-1α) and vascular endothelial growth factor (VEGF)], and small extracellular vesicle markers, (Alix, Syntenin and CD9) increased significantly in the culture supernatants. When primary human umbilical vein endothelial cells (HUVEC) were cultured with PLVPsv, polygon formation, number, and tube formation length was significantly increased compared to cells not treated with PLVPsv, indicating PLVPsv stimulated angiogenesis. We conclude that adding PLVPsv stimulates angiogenesis and vessel stabilization on neighboring endothelial cells in response to hypoxia in term pregnancy compared to no addition of PLVPsv. Our finding that PLVP can release angiogenic molecules via extracellular vesicles in response to hypoxia may apply to other organ systems.

Novel therapeutic and diagnostic approaches for preeclampsia.

PURPOSE OF REVIEW: This review will summarize recent findings relating to the diagnostic approach to preeclampsia and current avenues of research aimed at modifying the underlying disease process. RECENT FINDINGS: Growing international consensus supports a broad preeclampsia definition that incorporates maternal end-organ and uteroplacental dysfunction. Recent evidence demonstrates that this definition better identifies women and babies at risk of adverse outcomes compared to the traditional definition of hypertension and proteinuria. Multiple studies have demonstrated the usefulness and cost-effectiveness of angiogenic biomarkers such as soluble fms-like tyrosine kinase-1 and placental growth factor as a clinical adjunct to diagnose and predict severity of preeclampsia associated outcomes. Current novel therapeutic approaches to preeclampsia target pathogenic pathways (e.g. antiangiogenesis) or downstream effects such as oxidative stress and nitric oxide. Recent findings relating to these promising candidates are discussed. Multicenter clinical trials are needed to evaluate their effectiveness and ability to improve fetal and maternal outcomes. SUMMARY: We provide an updated framework of the current approaches to define and diagnose preeclampsia. Disease modifying therapies (in particular, targeting the angiogenic pathway) are being developed for the first time and promise to revolutionize the way we manage preeclampsia.

The sFlt1/PlGF ratio predicts faster fetal deterioration in early fetal growth restriction: A historical cohort study.

INTRODUCTION: The velocity of fetal deterioration in fetal growth restriction is extremely variable, which makes monitoring and counseling very challenging. The soluble fms-like tyrosine kinase to placental growth factor (sFlt1/PlGF) ratio provides a readout of the vasoactive environment that correlates with preeclampsia and fetal growth restriction and that could be useful to predict fetal deterioration. Previous studies showed a correlation between higher sFlt1/PlGF ratios and lower gestational ages at birth, although it is unclear whether this is due to the increased incidence of preeclampsia. Our goal was to evaluate whether the sFlt1/PlGF ratio predicts faster fetal deterioration in early fetal growth restriction. MATERIAL AND METHODS: This was a historical cohort study in a tertiary maternity hospital. Data from singleton pregnancies with early fetal growth restriction (diagnosed before 32 gestational weeks) confirmed after birth monitored between January 2016 and December 2020 were retrieved from clinical files. Cases of chromosomal/fetal abnormalities, infection and medical terminations of pregnancy were excluded. The sFlt1/PlGF ratio was acquired at diagnosis of early fetal growth restriction in our unit. The correlation of log10 sFlt1/PlGF with latency to delivery/fetal demise was assessed with linear, logistic (positive sFlt1/PlGF if >85) and Cox regression excluding deliveries for maternal conditions and controlling for preeclampsia, gestational age at time of ratio test, maternal age and smoking during pregnancy. Receiver-operating characteristic (ROC) analysis tested the performance of sFlt1/PlGF ratio in predicting delivery for fetal reasons in the following week. RESULTS: 125 patients were included. Mean sFlt1/PlGF ratio was 91.2 (SD 148.7) and 28% of patients had a positive ratio. A higher log10 sFlt1/PlGF ratio predicted shorter latency for delivery/fetal demise in linear regression after controlling for confounders, ß = -3.001, (-3.713 to -2.288). Logistic regression with ratio positivity confirmed these findings (latency for delivery 5.7 ± 3.32 weeks for ratios ≤85 vs 1.9 ± 1.52 weeks for ratios >85); ß = -0.698 (-1.064 to -0.332). Adjusted Cox regression showed that a positive ratio confers a significantly positive hazard ratio (HR) for earlier delivery/fetal demise, HR 9.869 (5.061-19.243). ROC analysis showed an area under the curve of 0.847 (SE ± 0.06). CONCLUSIONS: sFlt1/PlGF ratio is correlated with faster fetal deterioration in early fetal growth restriction, independently of preeclampsia.

Syncytiotrophoblast-derived extracellular vesicles carry apolipoprotein-E and affect lipid synthesis of liver cells in vitro.

In normal pregnancy, hepatic metabolism adaptation occurs with an increase in lipid biosynthesis. Placental shedding of syncytiotrophoblast-derived extracellular vesicles (STBEVs) into the maternal circulation constitutes a major signalling mechanism between foetus and mother. We investigated whether STBEVs from normal pregnant women might target liver cells in vitro and induce changes in lipid synthesis. This study was performed at the Nuffield Department of Women's & Reproductive Health, Oxford, UK. STBEVs were obtained by dual-lobe placental perfusion from 11 normal pregnancies at term. Medium/large and small STBEVs were collected by ultracentrifugation at 10,000g and 150,000g, respectively. STBEVs were analysed by Western blot analysis and flow cytometry for co-expression of apolipoprotein-E (apoE) and placental alkaline phosphatase (PLAP). The uptake of STBEVs by liver cells and the effect on lipid metabolism was evaluated using a hepatocarcinoma cell line (HepG2 cells). Data were analysed by one-way ANOVA and Student's t test. We demonstrated that: (a) STBEVs carry apoE; (b) HepG2 cells take up STBEVs through an apoE-LDL receptor interaction; (c) STBEV incorporation into HepG2 cells resulted in (i) increased cholesterol release (ELISA); (ii) increased expression of the genes SQLE and FDPS (microarray) involved in cholesterol biosynthesis; (iii) downregulation of the CLOCK gene (microarray and PCR), involved in the circadian negative control of lipid synthesis in liver cells. In conclusion, the placenta may orchestrate the metabolic adaptation of the maternal liver through release of apoE-positive STBEVs, by increasing lipid synthesis in a circadian-independent fashion, meeting the nutritional needs of the growing foetus.

Neuropilin-1 is uniquely expressed on small syncytiotrophoblast extracellular vesicles but not on medium/large vesicles from preeclampsia and normal placentae.

Preeclampsia (PE) is a multisystem progressive hypertensive disorder unique to human pregnancy. The placenta is fundamental to its pathogenesis and releases placental factors as well as extracellular vesicles (small and medium/large syncytiotrophoblast extracellular vesicles (STB-EVs)) as a response to syncytiotrophoblast stress such as tissue factor and plasminogen activator inhibitors 1. Neuropilin 1 (NRP-1) is an anti-angiogenic factor involved in development, angiogenesis, arteriogenesis, and vascular permeability. NRP-1 acts as a co-receptor for growth factors such as vascular endothelial growth factor (VEGF), placenta growth factor (PLGF), and epidermal growth factor (EGF). Given the documented pro and anti-angiogenic roles of STB-EVs, we hypothesized that 1) STB-EVs might express NRP-1; and 2) the expression of NRP-1 might differ between normal and preeclampsia STB-EVs. METHODS: We isolated STB-EVs (both small and medium/large) from PE and NP placentae using the physiologic ex vivo dual lobe perfusion model. The enriched STB-EVs were characterized by Western blot, transmission electron microscopy (TEM), and nanoparticle tracking analysis (NTA) according to the international society of extracellular vesicles (ISEV) guidelines. We assessed for NRP-1 expression with Western blot (placenta and STB-EVs) and immunohistochemistry (placenta). We performed co-expression analysis for placenta alkaline phosphatase (PLAP - a known STB-EV marker) and NRP-1 with immunoprecipitation followed by Western blot. RESULTS: We confirmed NRP-1 expression in NP and PE placenta. We showed that NRP-1 Expression was limited to small syncytiotrophoblast membrane extracellular vesicles (S STB-EVs) but not medium/large STB-EVs and that NRP-1 is co-expressed with PLAP. CONCLUSION: Neuropilin-1 is uniquely expressed on small syncytiotrophoblast extracellular vesicles but not on medium/large vesicles from preeclampsia and normal placentae.

Preeclampsia and syncytiotrophoblast membrane extracellular vesicles (STB-EVs).

Preeclampsia (PE) is a hypertensive complication of pregnancy that affects 2-8% of women worldwide and is one of the leading causes of maternal deaths and premature birth. PE can occur early in pregnancy (<34 weeks gestation) or late in pregnancy (>34 weeks gestation). Whilst the placenta is clearly implicated in early onset PE (EOPE), late onset PE (LOPE) is less clear with some believing the disease is entirely maternal whilst others believe that there is an interplay between maternal systems and the placenta. In both types of PE, the syncytiotrophoblast (STB), the layer of the placenta in direct contact with maternal blood, is stressed. In EOPE, the STB is oxidatively stressed in early pregnancy (leading to PE later in gestation- the two-stage model) whilst in LOPE the STB is stressed because of villous overcrowding and senescence later in pregnancy. It is this stress that perturbs maternal systems leading to the clinical manifestations of PE. Whilst some of the molecular species driving this stress have been identified, none completely explain the multisystem nature of PE. Syncytiotrophoblast membrane vesicles (STB-EVs) are a potential contributor to this multisystem disorder. STB-EVs are released into the maternal circulation in increasing amounts with advancing gestational age, and this release is further exacerbated with stress. There are good in vitro evidence that STB-EVs are taken up by macrophages and liver cells with additional evidence supporting endothelial cell uptake. STB-EV targeting remains in the early stages of discovery. In this review, we highlight the role of STB-EVs in PE. In relation to current research, we discuss different protocols for ex vivo isolation of STB-EVs, as well as specific issues involving tissue preparation, isolation (some of which may be unique to STB-EVs), and methods for their analysis. We suggest potential solutions for these challenges.

How should we interpret lactate in labour? A reference study.

OBJECTIVE: To investigate maternal lactate concentrations in labour and the puerperium. DESIGN: Reference study. SETTING: Tertiary obstetric unit. POPULATION: 1279 pregnant women with good perinatal outcomes at term. METHODS: Electronic patient records were searched for women who had lactate measured on the day of delivery or in the following 24 hours, but who were subsequently found to have a very low likelihood of sepsis, based on their outcomes. MAIN OUTCOME MEASURES: The normative distribution of lactate and C-reactive protein (CRP), differences according to the mode of birth, and the proportion of results above the commonly used cut-offs (≥2 and ≥4 mmol/l). RESULTS: Lactate varied between 0.4-5.4 mmol/l (median 1.8 mmol/l, interquartile range [IQR] 1.3-2.5). It was higher in women who had vaginal deliveries than caesarean sections (median 1.9 vs. 1.6 mmol/l, pdiff  < 0.001), demonstrating the association with labour (particularly active pushing in the second stage). In contrast, CRP was more elevated in women who had caesarean sections (median 71.8 mg/l) than those who had vaginal deliveries (33.4 mg/l, pdiff  < 0.001). In total, 40.8% had a lactate ≥2 mmol/l, but 95.3% were <4 mmol/l. CONCLUSIONS: Lactate in labour and the puerperium is commonly elevated above the levels expected in healthy pregnant or non-pregnant women. There is a paucity of evidence to support using lactate or CRP to make decisions about antibiotics around the time of delivery but, as lactate is rarely higher than 4 mmol/l, this upper limit may still represent a useful severity marker for the investigation and management of sepsis in labour.

The prognostic utility of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PIGF) biomarkers for predicting preeclampsia: a secondary analysis of data from the INSPIRE trial.

OBJECTIVE: To compare the prognostic performance of biomarkers soluble fms-like tyrosine kinase-1 (sFlt-1), Placental Growth Factor (PIGF), and sFlt-1/PIGF ratio as continuous values or as a binary cut-off of 38 for predicting preeclampsia (PE) within 7 days. DESIGN: Secondary analysis of a randomised clinical trial. SETTING: Oxford University Hospitals, Oxford, United Kingdom (UK). POPULATION: Pregnant women between 24+0 to 37+0 weeks of gestation with a clinical suspicion of preeclampsia. MAIN OUTCOME: Onset of preeclampsia within 7 days of the initial biomarker test. METHODS: Logistic regression model for onset of preeclampsia using: (i) sFlt-1 (ii) PIGF, (iii) sFlt-1/PIGF ratio (continuous), and (iv) sFlt-1/PIGF ratio as a cut-off above or below 38. RESULTS: Of the total 370 women, 42 (11.3%) developed PE within 7 days of screening. Models with sFlt-1 and sFlt-1/PIGF ratio (continuous) had greater overall performance than models with PIGF or with sFlt-1/PIGF ratio as a cut-off at 38 (R2: sFlt-1 = 55%, PIGF = 38%, sFlt-1/PIGF ratio = 57%, sFlt-1/PIGF ratio as cut-off at 38 model = 46%). The discrimination performance was the highest in sFlt-1 and sFlt-1/PIGF ratio (continuous) (c-statistic, sFlt-1 = 0.94, sFlt-1/PIGF ratio (continuous) = 0.94) models compared to PIGF or sFlt-1/PIGF cut-off models (c-statistic, PIGF = 0.87, sFlt-1/PIGF cut-off = 0.89). CONCLUSION: Models using continuous values of sFlt-1 only or sFlt-1/PIGF ratio had better predictive performance compared to a PIGF only or the model with sFlt-1/PIGF ratio as a cut-off at 38. Further studies based on a larger sample size are warranted to substantiate this finding.

The impact of a routine late third trimester growth scan on the incidence, diagnosis, and management of breech presentation in Oxfordshire, UK: A cohort study.

BACKGROUND: Breech presentation at term contributes significantly to cesarean section (CS) rates worldwide. External cephalic version (ECV) is a safe procedure that reduces term breech presentation and associated CS. A principal barrier to ECV is failure to diagnose breech presentation. Failure to diagnose breech presentation also leads to emergency CS or unplanned vaginal breech birth. Recent evidence suggests that undiagnosed breech might be eliminated using a third trimester scan. Our aim was to evaluate the impact of introducing a routine 36-week scan on the incidence of breech presentation and of undiagnosed breech presentation. METHODS AND FINDINGS: We carried out a population-based cohort study of pregnant women in a single unit covering Oxfordshire, United Kingdom. All women delivering between 37+0 and 42+6 weeks gestational age, with a singleton, nonanomalous fetus over a 4-year period (01 October 2014 to 30 September 2018) were included. The mean maternal age was 31 years, mean BMI 26, 44% were nulliparous, and 21% were of non-white ethnicity. Comparisons between the 2 years before and after introduction of routine 36-week scan were made for 2 primary outcomes of (1) the incidence of breech presentation and (2) undiagnosed breech presentation. Secondary outcomes related to ECV, mode of birth, and perinatal outcomes. Relative risks (RRs) with 95% confidence intervals (CIs) are reported. A total of 27,825 pregnancies were analysed (14,444 before and 13,381 after). A scan after 35+0 weeks was performed in 5,578 (38.6%) before, and 13,251 (99.0%) after (p < 0.001). The incidence of breech presentation at birth did not change significantly (2.6% and 2.7%) (RR 1.02; 95% CI 0.89, 1.18; p = 0.76). The rate of undiagnosed breech before labour reduced, from 22.3% to 4.7% (RR 0.21; 95% CI 0.12, 0.36; p < 0.001). Vaginal breech birth rates fell from 10.3% to 5.3% (RR 0.51; 95% CI 0.30, 0.87; p = 0.01); nonsignificant increases in elective CS rates and decreases in emergency CS rates for breech babies were seen. Neonatal outcomes were not significantly altered. Study limitations include insufficient numbers to detect serious adverse outcomes, that we cannot exclude secular changes over time which may have influenced our results, and that these findings are most applicable where a comprehensive ECV service exists. CONCLUSIONS: In this study, a universal 36-week scan policy was associated with a reduction in the incidence but not elimination of undiagnosed term breech presentation. There was no reduction in the incidence of breech presentation at birth, despite a comprehensive ECV service.

Correction: The impact of a routine late third trimester growth scan on the incidence, diagnosis, and management of breech presentation in Oxfordshire, UK: A cohort study.

[This corrects the article DOI: 10.1371/journal.pmed.1003503.].

Glycosylated Siglec-6 expression in syncytiotrophoblast-derived extracellular vesicles from preeclampsia placentas.

INTRODUCTION: Preeclampsia (PE) is associated with an exaggerated maternal systemic inflammatory response. Throughout gestation, the placenta releases extracellular vesicles through the syncytiotrophoblast layer (STB) into the maternal circulation and this is increased in PE. Expression of Siglec-6, a transmembrane receptor of molecular weight 50 KDa, is upregulated in PE placental tissue. METHODS: Here we investigated respective abundance of Siglec-6 in PE -and normal pregnancy- (NP) derived placental lysates (PL) and syncytiotrophoblast-derived extracellular vesicles (STBEV). STBEV from PE and NP placentas were isolated through dual-lobe placental perfusion and serial ultracentrifugation. Siglec-6 was characterized by immunohistochemistry, immunoblotting, mass spectrometry (MS), and deglycosylation. RESULTS: Immunoblotting revealed the expected Siglec-6 (50 KDa) band present in both PE and NP PL, however an additional heavier band was observed at 70 KDa only in PE PL, but not in NP. When interrogating STBEV we saw an absence of the expected 50 KDa band but the 70 KDa was present predominantly only in the PE STBEV. Deglycosylation of PL and STBEV from PE showed that the 70 KDa and the 50 KDa bands were reduced to 48 KDa, suggesting glycosylation. Both 48 KDa and 70 KDa bands were subjected to MS, confirming Siglec-6 expression in both. DISCUSSION: Our data shows that the inability to detect Siglec-6 in circulation might be due to the placenta secreting STBEV carrying a modified glycosylated form of Siglec-6 with a 70 KDa molecular weight, significantly and uniquely upregulated in PE STBEV.

Abnormal uterine inflammation in obstetric syndromes: molecular insights into the role of chemokine decoy receptor D6 and inflammasome NLRP3.

The adaptation of the uterine environment into a favorable immunological and inflammatory milieu is a physiological process needed in normal pregnancy. A uterine hyperinflammatory state, whether idiopathic or secondary to hormonal or organic uterine disorders (polycystic ovary syndromes, endometriosis/adenomyosis and fibroids), negatively influences the interactions between decidua and trophoblast, early in gestation, and between chorion and decidua later in pregnancy. Abnormal activation of uterine inflammatory pathways not only contributes to the pathogenesis of the obstetric syndromes, i.e. recurrent pregnancy loss (RPL), pre-term delivery (PTD) and pre-eclampsia (PE), but also to correlates with severity. In this review, we summarize recent advances in the knowledge of uterine molecular mechanisms of inflammatory modulation in normal pregnancy and obstetric syndromes (RPL, PTD and PE). In particular, we focus on two regulators of uterine/placental inflammation: the NLRP3 inflammasome and the chemokines decoy receptor D6. We performed comprehensive review of the literature in PubMed and Google Scholar databases from 1994 to 2018. The available evidence suggests that: (i) the expression of inflammasome NLRP3 is increased in the endometrium of women with unexplained RPL, in the chorioamniotic membranes of women with PTL and in the placenta of women with PE; (ii) there is a role for abnormal expression and function of D6 decoy receptor at the feto-maternal interface in cases of RPL and PTD and (iii) the function of placental D6 decoy receptor is impaired in PE. A wider comprehension of the inflammatory molecular mechanisms involved in the pathogenesis of the obstetric syndromes might lead to the identification of new potential therapeutic targets.

Exosomal Th1/Th2 cytokines in preeclampsia and HIV-positive preeclamptic women on highly active anti-retroviral therapy.

Preeclampsia (PE) is a hypertensive disorder of pregnancy which is a leading cause of maternal and foetal morbidity and mortality. Furthermore, HIV/Highly Active Anti-Retroviral Treatment has been associated with the increased risk of preeclampsia due to maternal immune reconstitution, which complicates the clinical diagnosis of PE in these patients. It is therefore necessary to identify biomarkers involved in the pathology of both disorders with the intent to diagnose. Exosomal cytokines represent ideal biomarkers of PE and inflammatory conditions due to their immunomodulatory role in pregnancy. We therefore quantified exosomal Th1 (IL-2 and TNF-α) and Th2 cytokines (IL-10) in maternal circulation. A significant dysregulation in total exosomes, placental-derived exosomes and exosomal cytokines in PE and HIV-positive PE pregnant woman on Highly Active Antiretroviral Treatment (HAART) was observed (p < 0.01). Additionally, we observed a significant shift towards Th1 immunity in PE which becomes amplified in HIV-positive PE pregnant woman on HAART (p < 0.01). Moreover, we show the potential application of exosomal Tumor necrosis factor alpha (TNF-α) as a biomarker of PE and PE in HIV-positive pregnant women on HAART (CI: 95%, LHR > 10, sensitivity of 100% and specificity of 90%). These findings are in support of exosome release and exosome cytokine encapsulation as a tightly regulated process in favour of maintaining the immune microenvironment, which can orchestrate either normal pregnancy, or the pathogenesis of preeclampsia and preeclampsia in HIV/HAART pregnancies.

Exosomal MicroRNAs in Pregnancy Provides Insight into a Possible Cure for Cancer.

The biological links between cancer and pregnancy are of recent interest due to parallel proliferative, immunosuppressive and invasive mechanisms between tumour and trophoblast development. Therefore, understanding "cancer-like" mechanisms in pregnancy could lead to the development of novel cancer therapeutics, however, little is understood on how tumour and trophoblast cells recapitulate similar molecular mechanisms. Based on our observations from a previous study, it was not only evident that exosomal miRNAs are involved in the pathophysiology of preeclampsia but also contained cancer-specific miRNAs, which suggested that "pseudo-malignant-like" exosomal-mediated mechanisms exist in pregnancy. The presented study therefore aimed to identify exosomal miRNAs (exomiR) in pregnancy which can be repurposed towards preventing tumour metastasis and immunosuppression. It was identified that exomiR-302d-3p, exomiR-223-3p and exomiR-451a, commonly associated with cancer metastasis, were found to be highly expressed in pregnancy. Furthermore, computational merging and meta-analytical pathway analysis (DIANA miRPath) of significantly expressed exomiRs between 38 ± 1.9 vs. 30 ± 1.11 weeks of gestation indicated controlled regulation of biological pathways associated with cancer metastasis and immunosuppression. Therefore, the observations made in this study provide the experimental framework for the repurposing of exosomal miRNA molecular mechanisms in pregnancy towards treating and preventing cancer.

Predictive Value of the sFlt-1:PlGF Ratio in Women with Suspected Preeclampsia.

BACKGROUND: The ratio of soluble fms-like tyrosine kinase 1 (sFlt-1) to placental growth factor (PlGF) is elevated in pregnant women before the clinical onset of preeclampsia, but its predictive value in women with suspected preeclampsia is unclear. METHODS: We performed a prospective, multicenter, observational study to derive and validate a ratio of serum sFlt-1 to PlGF that would be predictive of the absence or presence of preeclampsia in the short term in women with singleton pregnancies in whom preeclampsia was suspected (24 weeks 0 days to 36 weeks 6 days of gestation). Primary objectives were to assess whether low sFlt-1:PlGF ratios (at or below a derived cutoff) predict the absence of preeclampsia within 1 week after the first visit and whether high ratios (above the cutoff) predict the presence of preeclampsia within 4 weeks. RESULTS: In the development cohort (500 women), we identified an sFlt-1:PlGF ratio cutoff of 38 as having important predictive value. In a subsequent validation study among an additional 550 women, an sFlt-1:PlGF ratio of 38 or lower had a negative predictive value (i.e., no preeclampsia in the subsequent week) of 99.3% (95% confidence interval [CI], 97.9 to 99.9), with 80.0% sensitivity (95% CI, 51.9 to 95.7) and 78.3% specificity (95% CI, 74.6 to 81.7). The positive predictive value of an sFlt-1:PlGF ratio above 38 for a diagnosis of preeclampsia within 4 weeks was 36.7% (95% CI, 28.4 to 45.7), with 66.2% sensitivity (95% CI, 54.0 to 77.0) and 83.1% specificity (95% CI, 79.4 to 86.3). CONCLUSIONS: An sFlt-1:PlGF ratio of 38 or lower can be used to predict the short-term absence of preeclampsia in women in whom the syndrome is suspected clinically. (Funded by Roche Diagnostics.).