Placental Growth Factor Ratio Research Articles

Repeat Placental Growth Factor-Based Testing in Women With Suspected Preterm Preeclampsia: A Stratified Analysis of the PARROT-2 Trial.

PlGF (placental growth factor)-based testing reduces severe maternal adverse outcomes. Repeat PlGF-based testing is not associated with improved perinatal or maternal outcomes. This planned secondary analysis aimed to determine whether there is a subgroup of women who benefit from repeat testing. Pregnant individuals with suspected preterm preeclampsia were randomized to repeat revealed PlGF-based testing, compared with usual care where testing was concealed. Perinatal and maternal outcomes were stratified by trial group, by initial PlGF-based test result, and by PlGF-based test type (PlGF or sFlt-1 [soluble fms-like tyrosine kinase-1]/PlGF ratio). A total of 1252 pregnant individuals were included. Abnormal initial PlGF-based test identified a more severe phenotype of preeclampsia, at increased risk of adverse maternal and perinatal outcomes. Repeat testing was not significantly associated with clinical benefit in women with abnormal initial results. Of women with a normal initial result, 20% developed preeclampsia, with the majority at least 3 to 4 weeks after initial presentation. Repeat test results were more likely to change from normal to abnormal in symptomatic women (112/415; 27%) compared with asymptomatic women (163/890; 18%). A higher proportion of symptomatic women who changed from normal to abnormal were diagnosed with preeclampsia, compared with asymptomatic women. Our results do not demonstrate evidence of the clinical benefit of repeating PlGF-based testing if the initial result is abnormal. Judicious use of repeat PlGF-based testing to stratify risk may be considered at least 2 weeks after a normal initial test result, particularly in women who have symptoms or signs of preeclampsia. URL: XXX; Unique identifier: ISRCTN85912420.

Role of soluble fms-like tyrosine kinase-1/placental growth factor ratio along with uterine artery Doppler for the prediction of pre-eclampsia – A case–control study

Background: Hypertensive disorders of pregnancy are becoming the leading cause of maternal morbidity and mortality worldwide and are responsible for 9–25% of deaths 1. They are believed to occur due to an imbalance between pro-angiogenic factors, like placental growth factor (PlGF) and anti-angiogenic factors, like soluble fms-like tyrosine kinase-1 (sFLT-1). Aims and Objectives: The aim of the study was to evaluate the role of the sFLT-1/PlGF ratio along with uterine artery Doppler for the prediction of pre-eclampsia (PE). Materials and Methods: The current study was a prospective case–control study conducted at Sri Ramachandra Medical College and Hospital, Chennai, from 2018 to 2020. Blood samples for sFLT-1 and PlGF and uterine artery Doppler were done in 100 pregnant mothers who are at 16–20-week gestation attending antenatal outpatient department in the Department of Obstetrics and Gynecology. Results: We found that the mean sFLT-1 in high-risk group was 826.17 ng/L (standard deviation [SD]±251.31) compared to 924.69 ng/L (SD±360.61) in low-risk groups. The mean PlGF in the high-risk group was 23.07 ng/L (SD±4.68) compared to 27.43 ng/L (SD±5.62) in low-risk group. The mean sFLT-1/PlGF ratio was increased in high-risk group of about 39.68 (SD±22.77) compared to 35 (SD±16.98) in low-risk group. Women with high resistance uterine artery Doppler have 8.5 odds of getting PE compared to those with normal uterine artery Doppler. Conclusion: According to our study, the sFLT-1/PlGF ratio carries more sensitivity (90%) and negative predictive value (74.19%) if we keep the value as 32.25 along with uterine Doppler rather than their individual values for the prediction of PE.

Stability of serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1)

Placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1) are biomarkers used for diagnosis and risk estimation of preeclampsia. Stability in room temperature (RT) may affect the usefulness of these analyses, as shipping at ambient temperature is the most practical and suitable way to ship samples. To date, scientific studies of such stability are lacking. We aimed to assess the stability of PlGF and sFlt-1 at RT in serum from pregnant women. In addition, a smaller study of stability at 4 °C was performed. Serum was collected from 69 pregnant women and stored at RT or at 4 °C for up to 192 h. Analytes were considered stable if the mean percent change ± 90 confidence interval of the mean was within the baseline concentration ± allowable bias. Allowable bias was calculated from data on biological variation. In addition, an instability equation was calculated to assess loss of stability, in line with recent European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recommendations. The mean percent change was <3.5% for PlGF, <1% for sFlt-1 and <4.5% for sFlt-1/PlGF ratio up to 192 h. PlGF was considered stable for 168 h, and sFlt-1 and sFlt-1/PlGF ratios were considered stable for 192 h at RT. At 4 °C, PlGF was considered stable for 120 h, sFlt-1 for 168 h and sFlt-1/PlGF ratio for 120 h. Both PlGF and sFlt-1 as well as sFlt-1/PlGF ratio show sufficient stability (minimum 168 h) for samples to be shipped at RT.

A Second Trimester Prediction Algorithm for Early-Onset Hypertensive Disorders of Pregnancy Occurrence and Severity Based on Soluble fms-like Tyrosine Kinase 1 (sFlt-1)/Placental Growth Factor (PlGF) Ratio and Uterine Doppler Ultrasound in Women at Risk.

Hypertensive disorders of pregnancy (HDPs) represent a significant source of severe maternal and fetal morbidity. Screening strategies relying on traditional medical history and clinical risk factors have traditionally shown relatively modest performance, mainly in the prediction of preeclampsia, displaying a sensitivity of 37% for the early-onset form and 29% for the late-onset form. The development of more accurate predictive and diagnostic models of preeclampsia in the early stages of pregnancy represents a matter of high priority. The aim of the present paper is to create an effective second trimester prediction algorithm of early-onset HDP occurrence and severity, by combining the following two biochemical markers: a soluble fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio and uterine artery Doppler ultrasound parameters, namely the pulsatility index (PI) and the resistivity index (RI), in a population of high-risk pregnant women, initially assessed through traditional risk factors. A prospective single-center observational longitudinal study was conducted, in which 100 women with singleton pregnancy and traditional clinical and medical history risk factors for preeclampsia were enrolled at 24 weeks of gestation. Shortly after study enrollment, all women had their sFlt-1 and PlGF levels and mean uterine artery PI and RI determined. All pregnancies were followed up until delivery. Receiver operating characteristic (ROC) analysis established algorithms based on cutoffs for the prediction of the later development of preeclampsia: PI 1.25 (96.15% sensitivity, 86.49% specificity), RI 0.62 (84.6% sensitivity, 89.2% specificity) and sFlt-1/PlGF ratio 59.55 (100% sensitivity, 89.2% specificity). The sFlt-1/PlGF ratio was the best predictor for preeclampsia, as it displayed the highest area under the curve (AUC) of 0.973. The prediction algorithm for the severe form of preeclampsia, complicated by fetal growth restriction leading to preterm birth, antepartum fetal demise or acute fetal distress with a cerebro-placental ratio of <one consisted of the following cutoffs: PI 1.44 (93.75% sensitivity, 95.24% specificity), RI 0.69 (87.5% sensitivity, 100% specificity) and sFlt-1/PlGF ratio 102.74 (93.75% sensitivity, 95.2% specificity). These algorithms may significantly enhance the prediction accuracy of preeclampsia compared to traditional risk factors. The combination of the sFlt-1/PlGF ratio with mean uterine PI and RI in particular displayed an improved performance in the prediction of severe preeclampsia with the above-mentioned complications, compared to the biochemical markers or uterine Doppler parameters used alone. Therefore, HDP screening strategies should increasingly focus on implementing such algorithms for women who are initially regarded as high risk based on traditional risk factors, in order to properly diagnose HDP and properly limit or manage the later maternal and fetal complications.

Tumor Necrosis Factor Inhibitor Use Increases Birthweight in Pregnant Women With Rheumatoid Arthritis Independently of the Soluble Fms-Like Tyrosine Kinase-1/Placental Growth Factor Ratio.

To study whether the use of TNF (tumor necrosis factor) inhibitors (TNFi) by pregnant women with rheumatoid arthritis affects sFlt-1 (soluble Fms-like tyrosine kinase-1), PlGF (placental growth factor), or their impact on birthweight. sFlt-1 and PlGF were measured in all trimesters of pregnancy in the Preconception Counseling in Active Rheumatoid Arthritis study and were compared according to the use of TNFi. The association of sFlt-1 and PlGF with birthweight in relation to TNFi was determined. The study included 158 women, of whom 52.5% used TNFi during pregnancy. Both sFlt-1 and PlGF increased during pregnancy, whereas their ratio declined. Taking into consideration the trimester-related variation in levels of sFlt-1 and PlGF, after correction for relevant confounders, the sFlt-1/PlGF ratio was not significantly different between patients who did or did not use TNFi (sFlt-1/PlGF ratio in the second trimester compared with the first trimester: estimated change 8.17 [95% CI, 2.54-26.29], P=0.79; sFlt-1/PlGF ratio in the third trimester compared with the first trimester: estimated change 6.25 [95% CI, 1.73-22.50], P=0.25). In women who did not use TNFi, birthweight was significantly lower (3180 versus 3302 g; P=0.03), and sFlt-1 displayed a negative correlation with birthweight (r=-0.462, P<0.001) and birthweight percentile (r=-0.332, P=0.008). In TNFi users, these correlations were absent. TNF inhibitor use increases birthweight in pregnant women with rheumatoid arthritis independently of the sFlt-1/PlGF ratio. http://clinicaltrials.gov. Unique identifier: NCT01345071.

Pathogenetic traits of preeclampsia in COVID-19. A relevant literature review

The aim of this study was to present the latest data on the association of preeclampsia and coronavirus infection and on the preeclampsia-like syndrome, and to analyze the current literature on the pathogenetic relationships between COVID-19 and preeclampsia and on morphological changes in placental tissue in patients with these gestational complications.&#x0D; A significant portion of studies indicate an increased risk of developing preeclampsia in patients with coronavirus infection during pregnancy, regardless of gestational age, especially in severe COVID-19, but other researchers report no association between coronavirus infection and the onset of preeclampsia. The supposed pathogenetic connection between these pathologies consists in the development of systemic endothelial dysfunction and dysregulation of the renin-angiotensin-aldosterone system, while the direct effect of SARS-CoV-2 on the placentation is poorly understood and is a subject of debate. A new concept of the so-called “preeclampsia-like syndrome” has been introduced, which presumably occurs in patients with a severe form of the novel coronavirus infection as its extrapulmonary manifestation. The measurement of the ratio of soluble fms-like tyrosine kinase-1 activity to the level of placental growth factor ratio has been proposed as a differential diagnostic test between preeclampsia and the preeclampsia-like syndrome, but its prognostic value remains ambiguous. The morphological examination of placentas in patients with coronavirus infection and preeclampsia indicates the signs of maternal and fetal vascular malperfusion.&#x0D; The literature on the association between coronavirus infection and preeclampsia remains controversial, however, the better half of the researchers is indicative of a significant increase in the risk of developing this serious complication in pregnant women with COVID-19, especially for its severe form. New information about the preeclampsia-like syndrome, as well as the virtual absence of studies of placental morphology in patients with preeclampsia and coronavirus infection during pregnancy, dictate the need for further study to better understand the association between these two pathologies, determine the possibilities of patient surveillance and prevent complications.

Angiogenic imbalance in pregnancies with preterm prelabor rupture of membranes between 34 and 37 weeks of gestation.

This study aimed to identify whether microbial invasion of the amniotic cavity and/or intra-amniotic inflammation in women with late preterm prelabor rupture of membranes (PPROM) was associated with changes in concentrations of soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF) and its ratio in maternal serum, and whether placental features consistent with maternal vascular malperfusion further affect their concentrations. This historical study included 154 women with singleton pregnancies complicated by PPROM between gestational ages 34+0 and 36+6 weeks. Transabdominal amniocentesis was performed as part of standard clinical management to evaluate the intra-amniotic environment. Women were categorized into two subgroups based on the presence of microorganisms and/or their nucleic acids in amniotic fluid (determined by culturing and molecular biology method) and intra-amniotic inflammation (by amniotic fluid interleukin-6 concentration evaluation): (1) those with the presence of microorganisms and/or inflammation (at least one present) and (2) those with negative amniotic fluid for infection/inflammation (absence of both). Concentrations of sFlt-1 and PlGF were assessed using the Elecsys® sFlt-1 and Elecsys® PlGF immunoassays and converted into multiples of medians. Women with the presence of microorganisms and/or inflammation in amniotic fluid had lower serum concentrations of sFlt-1 and sFlt-1/PlGF ratios and higher concentrations of PlGF compared with those with negative amniotic fluid. (sFlt-1: presence: median 1.0 multiples of the median (MoM), vs negative: median: 1.5 MoM, P = 0.003; PlGF: presence: median 0.7 MoM, versus negative: median 0.4 MoM, P = 0.02; sFlt-1/PlGF: presence: median 8.9 vs negative 25.0, P = 0.001). Higher serum concentrations of sFlt-1 and sFlt-1/PlGF ratios as well as lower concentrations of PlGF were found in the subsets of women with maternal vascular malperfusion than in those without maternal vascular malperfusion. Among women experiencing late PPROM, angiogenic imbalance in maternal serum is primarily observed in those without both microbial invasion of the amniotic cavity and intra-amniotic inflammation. Additionally, there is an association between angiogenic imbalance and the presence of maternal vascular malperfusion.

Prediction of preterm birth in women with fetal growth restriction - Is the weekly change in sFlt-1/PlGF ratio or PlGF levels useful?

To assess the rate of change in soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio and PlGF levels per week compared to a single sFlt-1/PlGF ratio or PlGF level to predict preterm birth for pregnancies complicated by fetal growth restriction. A prospective cohort study of pregnancies complicated by isolated fetal growth restriction. Maternal serum PlGF levels and the sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. We investigated the utility of PlGF levels, sFlt-1/PlGF ratio, change in PlGF levels per week or sFlt-1/PlGF ratio per week. Cox-proportional hazard models and Harrell's C concordance statistic were used to evaluate the effect of biomarkers on time to preterm birth. The total study cohort was 158 pregnancies comprising 91 (57.6%) with fetal growth restriction and 67 (42.4%) with appropriate for gestational age controls. In the fetal growth restriction cohort, sFlt-1/PlGF ratio and PlGF levels significantly affected time to preterm birth (Harrell's C: 0.85-0.76). The rate of increase per week of the sFlt-1/PlGF ratio (hazard ratio [HR] 3.91, 95% confidence interval [CI]: 1.39-10.99, p = 0.01, Harrell's C: 0.74) was positively associated with preterm birth but change in PlGF levels per week was not (HR 0.65, 95% CI: 0.25-1.67, p = 0.37, Harrell's C: 0.68). Both a high sFlt-1/PlGF ratio and low PlGF levels are predictive of preterm birth in women with fetal growth restriction. Although the rate of increase of the sFlt-1/PlGF ratio predicts preterm birth, it is not superior to either a single elevated sFlt-1/PlGF ratio or low PlGF level.

Impact of physical activity on preeclampsia and angiogenic markers in the Finnish Genetics of Pre-eclampsia Consortium (FINNPEC) cohort

Introduction Effect of physical activity in pregnancy on preeclampsia (PE) and angiogenic markers is not well understood. We studied the association of physical activity and PE in a case-control setting and assessed whether exercise in PE and non-PE women associate with maternal serum concentrations of soluble fms-like tyrosine kinase 1 (s-Flt-1), placental growth factor (PlGF) and soluble endoglin (sEng) and sFlt-1/PlGF ratio in the Finnish Genetics of Pre-eclampsia Consortium (FINNPEC) cohort. Materials and methods Participants completed a questionnaire on their background information and serum samples were collected from a subset. Questionnaire data on physical activity were available from 708 PE women and 724 non-PE women. Both first trimester serum samples and questionnaire data on physical activity were available from 160 PE women and 160 non-PE women, and second/third trimester serum samples and questionnaire data on physical activity were available from 139 PE women and 47 non-PE women. The PE and non-PE women were divided into categories of physically active (exercise 2 − 3 times/week or more) and physically inactive (exercise less than 2 − 3 times/week). Results A total of 43.4% of the PE women and 42.4% of the non-PE women were categorized as physically active. There were no differences in physical activity and exercise habits between the groups. The physically active women were more often nulliparous and non-smokers and had a lower body mass index. There were no differences in the concentrations of angiogenic markers (sFlt-1, PlGF and sEng and sFlt-1/PlGF ratio) between the groups who exercised more or less than 2 − 3 times/week. Conclusions In the FINNPEC study cohort, there was no association between physical activity and PE and no associations of physical activity in pregnant women with and without PE with maternal serum concentrations of sFlt-1, PlGF and sEng and sFlt-1/PlGF ratio.

Multicentre randomised trial of screening with sFlt1/PlGF and planned delivery to prevent pre-eclampsia at term: protocol of the PE37 study

IntroductionPre-eclampsia affects ~5%–7% of pregnancies. Although improved obstetric care has significantly diminished its associated maternal mortality, it remains a leading cause of maternal morbidity and mortality in the world. Term...

Validation of a new kit for preeclampsia screening: A comprehensive analysis

ObjectivesPreeclampsia is a common pregnancy complication that significantly contributes to maternal mortality, perinatal mortality, and preterm delivery. The sFlt-1/PlGF (fms-like tyrosine kinase-1/placental growth factor) ratio has demonstrated robust diagnostic value for preeclampsia. This study assessed the analytical performance and diagnostic accuracy of a novel quantitative determination kit for sFlt-1 and PlGF for the diagnosis of preeclampsia. MethodsThe detection performance of the test kit was validated using the Center for Medical Device Evaluation (CMDE) and Clinical and Laboratory Standards Institute (CLSI) documents. The test results were compared to those of the Elecsys immunoassay (Roche Diagnostics). Independent discovery and validation sets were used to analyze the diagnostic efficacy of the preeclampsia kit. The area under the curve (AUC) for preeclampsia at different gestational ages was calculated. ResultsCorrelation analysis between the test and Roche kits revealed a strong concordance (sFlt-1: r = 0.9966, P < 0.0001; PlGF: r = 0.9935, P < 0.0001). The AUCs for sFlt-1, PlGF, and the sFlt-1/PlGF ratio in diagnosing preeclampsia were 0.749, 0.795, and 0.834, respectively, in the discovery set and 0.729, 0.811, and 0.831, respectively, in the validation set. The corresponding results from the Roche kit were 0.741, 0.795, and 0.829, respectively, and 0.761, 0.864, and 0.844, respectively. ConclusionsQuantitative sFlt-1 and PlGF kits exhibited high levels of consistency with the Roche kits in terms of quantitative outcomes and diagnostic performance for preeclampsia.

Statins Prevent the Deleterious Consequences of Placental Chemerin Upregulation in Preeclampsia.

Chemerin, an inflammatory adipokine, is upregulated in preeclampsia, and its placental overexpression results in preeclampsia-like symptoms in mice. Statins may lower chemerin. Chemerin was determined in a prospective cohort study in women suspected of preeclampsia and evaluated as a predictor versus the sFlt-1 (soluble fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio. Chemerin release was studied in perfused placentas and placental explants with or without the statins pravastatin and fluvastatin. We also addressed statin placental passage and the effects of chemerin in chorionic plate arteries. Serum chemerin was elevated in women with preeclampsia, and its addition to a predictive model yielded significant effects on top of the sFlt-1/PlGF ratio to predict preeclampsia and its fetal complications. Perfused placentas and explants of preeclamptic women released more chemerin and sFlt-1 and less PlGF than those of healthy pregnant women. Statins reversed this. Both statins entered the fetal compartment, and the fetal/maternal concentration ratio of pravastatin was twice that of fluvastatin. Chemerin constricted plate arteries, and this was blocked by a chemerin receptor antagonist and pravastatin. Chemerin did not potentiate endothelin-1 in chorionic plate arteries. In explants, statins upregulated low-density lipoprotein receptor expression, which relies on the same transcription factor as chemerin, and NO release. Chemerin is a biomarker for preeclampsia, and statins both prevent its placental upregulation and effects, in an NO and low-density lipoprotein receptor-dependent manner. Combined with their capacity to improve the sFlt-1/PlGF ratio, this offers an attractive mechanism by which statins may prevent or treat preeclampsia.

Maternal cardiovascular function at mid-gestation is related to placental angiogenesis.

To investigate whether placental function, reflected in the levels of angiogenic factors, is associated with maternal cardiac function and hemodynamic responses at 19 to 24 weeks' gestation after adjustment for maternal risk factors and pregnancy complications. Prospective study on women with singleton pregnancies attending Kings' College Hospital, London, UK for a routine hospital visit at 19-24 weeks' gestation. We recorded maternal characteristics and measured mean arterial pressure, maternal heart rate, serum placental growth factor and soluble fms-like tyrosine kinase 1 (sFLT-1).We also performed maternal echocardiogram to assess cardiac output and peripheral vascular resistance as well as indices of diastolic and systolic function. Our cohort included 4006 women.Lower placental growth factor (PlGF) values were significantly associated with higher mean arterial pressure (MAP) (p<0.001), lower maternal heart rate (p<0.001), lower mitral valve s' velocity (p= 0.027) and higher left atrial volume (p=0.022) after adjustment for maternal characteristics and pregnancy complications. sFLT-1 was positively related to relative wall thickness (p= 0.012), whereas sFLT-1/ PlGF ratio was negatively associated with mitral valve A (p= 0.006) and positively associated with left atrial volume (p= 0.015) and MAP (p= 0.004). The magnitude of these associations was similar in the subgroup of women without any risk factors from their obstetric and medical history. A continuous link of moderate strength between angiogenic factors and subclinical maternal cardiac function alterations is present at mid-gestation, independently of preexisting maternal risk factors and pregnancy complications. Impaired placental function appears to be related to a mild systolic and diastolic dysfunction and cardiac remodeling. This article is protected by copyright. All rights reserved.

Translation of mechanistic advances in preeclampsia to the clinic: Long and winding road.

As one of the leading causes of premature birth and maternal and infant mortality worldwide, preeclampsia remains a major unmet public health challenge. Preeclampsia and related hypertensive disorders of pregnancy are estimated to cause >75 000 maternal and 500 000 infant deaths globally each year. Because of rising rates of risk factors such as obesity, invitro fertilization and advanced maternal age, the incidence of preeclampsia is going up with rates ranging from 5% to 10% of all pregnancies worldwide. A major discovery in the field was the realization that the clinical phenotypes related to preeclampsia, such as hypertension, proteinuria, and other adverse maternal/fetal events, are due to excess circulating soluble fms-like tyrosine kinase-1 (sFlt-1, also referred to as sVEGFR-1). sFlt-1 is an endogenous anti-angiogenic protein that is made by the placenta and acts by neutralizing the pro-angiogenic proteins vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). During the last decade, this work has spawned a new era of molecular diagnostics for early detection of this condition. Antagonizing sFlt-1 either by reducing production or blocking its actions has shown salutary effects in animal models. Further, in early-stage human studies, the therapeutic removal of sFlt-1 from maternal circulation has shown promise in delaying disease progression and improving outcomes. Recently, the FDA approved the first molecular test for preterm preeclampsia (sFlt-1/PlGF ratio) for clinical use in the United States. Measuring serum sFlt-1/PlGF ratio in the acute hospital setting may aid short-term management, particularly regarding step-up or step-down of care, decision to transfer to settings better equipped to manage both the mother and the preterm neonate, appropriate timing of administration of steroids and magnesium sulfate, and in expectant management decisions. The test itself has the potential to save lives. Furthermore, the availability of a molecular test that correlates with adverse outcomes has set the stage for interventional clinical trials testing treatments for this disorder. In this review, we will discuss the role of circulating sFlt-1 and related factors in the pathogenesis of preeclampsia and specifically how this discovery is leading to concrete advances in the care of women with preeclampsia.

Potential urinary biomarkers in preeclampsia: a narrative review.

Preeclampsia (PE) is a highly relevant pregnancy-related disorder. An early and accurate diagnosis is crucial to prevent major maternal and neonatal complications and mortality. Due to the association of kidney dysfunction with the pathophysiology of the disease, urine samples have the potential to provide biomarkers for PE prediction, being minimally invasive and easy to perform. Therefore, searching for novel biomarkers may improve outcomes. This narrative review aimed to summarize the scientific literature about the traditional and potential urinary biomarkers in PE and to investigate their applicability to screen and diagnose the disorder. A non-systematic search was performed in PubMed/MEDLINE, Scopus, and SciELO databases. There is significant divergence in the literature regarding traditionally used serum markers creatinine, cystatin C, and albuminuria, accuracy in PE prediction. As for the potential renal biomarkers investigated, including vascular epithelial growth factor (VEGF), placental growth factor (PlGF), and soluble fms-like tyrosine kinase (sFlt-1), urinary levels of PlGF and sFtl-1/PlGF ratio in urine seem to be the most promising as screening tests. The assessment of the global load of misfolded proteins through urinary congophilia, podocyturia, and nephrinuria has also shown potential for screening and diagnosis. Studies regarding the use of proteomics and metabolomics have shown good accuracy, sensitivity, and specificity for predicting the development and severity of PE. However, there are still many divergences in the literature, which requires future and more conclusive research to confirm the predictive role of urinary biomarkers in pregnant women with PE.

Biomarkers in Peripartum Cardiomyopathy-What We Know and What Is Still to Be Found.

Peripartum cardiomyopathy (PPCM) is a form of heart failure, often severe, that occurs in previously healthy women at the end of their pregnancy or in the first few months after delivery. In PPCM, the recovery of heart function reaches 45-50%. However, the all-cause mortality in long-term observation remains high, reaching 20% irrespective of recovery status. The incidence of PPCM is increasing globally; therefore, effort is required to clarify the pathophysiological background of the disease, as well as to discover specific diagnostic and prognostic biomarkers. The etiology of the disease remains unclear, including oxidative stress; inflammation; hormonal disturbances; endothelial, microcirculatory, cardiomyocyte and extracellular matrix dysfunction; fibrosis; and genetic mutations. Currently, antiangiogenic 16-kDa prolactin (PRL), cleaved from standard 23-kDa PRL in the case of unbalanced oxidative stress, is recognized as the main trigger of the disease. In addition, 16-kDa PRL causes damage to cardiomyocytes, acting via microRNA-146a secreted from endothelial cells as a cause of the NF-κβ pathway. Bromocriptine, which inhibits the secretion of PRL from the pituitary gland, is now the only specific treatment for PPCM. Many different phenotypes of the disease, as well as cases of non-responders to bromocriptine treatment, indicate other pathophysiological pathways that need further investigation. Biomarkers in PPCM are not well established. There is a deficiency in specific diagnostic biomarkers. Pro-brain-type natriuretic peptide (BNP) and N-terminal BNP are the best, however unspecific, diagnostic biomarkers of heart failure at the moment. Therefore, more efforts should be engaged in investigating more specific biomolecules of a diagnostic and prognostic manner such as 16-kDa PRL, galectin-3, myeloperoxidase, or soluble Fms-like tyrosine kinase-1/placental growth factor ratio. In this review, we present the current state of knowledge and future directions of exploring PPCM pathophysiology, including microRNA and heat shock proteins, which may improve diagnosis, treatment monitoring, and the development of specific treatment strategies, and consequently improve patients' prognosis and outcome.

Ophthalmic artery Doppler at 36 weeks' gestation in prediction of pre-eclampsia: validation and update of previous model.

To validate and extend a model incorporating maternal ophthalmic artery Doppler at 35-37 weeks' gestation in the prediction of subsequent development of pre-eclampsia (PE). This was a prospective validation study of screening for PE (defined according to the 2019 American College of Obstetricians and Gynecologists criteria) by maternal ophthalmic artery peak systolic velocity (PSV) ratio in 6746 singleton pregnancies undergoing routine care at 35 + 0 to 36 + 6 weeks' gestation (validation dataset). Additionally, the data from the validation dataset were combined with those of 2287 pregnancies that were previously used for development of the model (training dataset), and the combined data were used to update the original model parameters. The competing-risks model was used to estimate the individual patient-specific risk of delivery with PE at any time and within 3 weeks from assessment by a combination of maternal demographic characteristics and medical history with PSV ratio alone and in combination with the established PE biomarkers of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and serum soluble fms-like tyrosine kinase-1 (sFlt-1). We evaluated the predictive performance of the model by examining, first, the ability to discriminate between the PE and non-PE groups using the area under the receiver-operating-characteristics curve and the detection rate (DR) at fixed screen-positive (SPR) and false-positive rates of 10% and, second, calibration by measuring the calibration slope and calibration-in-the-large. McNemar's test was used to compare the performance of screening by a biophysical test (maternal factors, MAP, UtA-PI and PSV ratio) vs a biochemical test (maternal factors, PlGF and sFlt-1), low PlGF concentration (< 10th percentile) or high sFlt-1/PlGF concentration ratio (> 90th percentile). In the validation dataset, the performance of screening by maternal factors and PSV ratio for delivery with PE within 3 weeks and at any time after assessment was consistent with that in the training dataset, and there was good agreement between the predicted and observed incidence of PE. In the combined data from the training and validation datasets, good prediction for PE was achieved in screening by a combination of maternal factors, MAP, UtA-PI, PlGF, sFlt-1 and PSV ratio, with a DR, at a 10% SPR, of 85.0% (95% CI, 76.5-91.4%) for delivery with PE within 3 weeks and 65.7% (95% CI, 59.2-71.7%) for delivery with PE at any time after assessment. The performance of a biophysical test was superior to that of screening by low PlGF concentration or high sFlt-1/PlGF concentration ratio but not significantly different from the performance of a biochemical test combining maternal factors with PlGF and sFlt-1 for both PE within 3 weeks and PE at any time after assessment. Maternal ophthalmic artery PSV ratio at 35-37 weeks' gestation in combination with other biomarkers provides effective prediction of subsequent development of PE. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Angiogenic markers and maternal echocardiographic indices in women with hypertensive disorders of pregnancy.

The maternal cardiovascular system of women with hypertensive disorders of pregnancy (HDP) can be impaired, with higher rates of left ventricular (LV) remodeling and diastolic dysfunction compared to those with normotensive pregnancy. The primary objective of this prospective study was to correlate cardiac indices obtained by transthoracic echocardiography (TTE) and circulating angiogenic markers, such as soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF). In this study, 95 women with a pregnancy complicated by HDP and a group of 25 with an uncomplicated pregnancy at term underwent TTE and blood tests to measure sFlt-1 and PlGF during the peripartum period (before delivery or within a week of giving birth). Spearman's rank correlation was used to derive correlation coefficients between biomarkers and cardiac indices in the HDP and control populations. The HDP group included 61 (64.2%) pre-eclamptic patients and, among them, 42 (68.9%) delivered before 37 weeks' gestation. Twelve women with HDP (12.6%) underwent blood sampling and TTE after delivery, and, as they showed significantly lower levels of angiogenic markers, they were excluded from the analysis. There was a correlation between sFlt-1 and LV mass index (LVMI) (r = 0.246; P = 0.026) and early diastolic mitral inflow velocity (E) and early diastolic mitral annular velocity (e') ratio (r = 0.272; P = 0.014) in the HDP group (n = 83), while in the controls, sFlt-1 showed a correlation with relative wall thickness (r = 0.409; P = 0.043), lateral e' (r = -0.562; P = 0.004) and E/e' ratio (r = 0.417; P = 0.042). PlGF correlated with LVMI (r = -0.238; P = 0.031) in HDP patients and with lateral e' (r = 0.466; P = 0.022) in controls. sFlt-1/PlGF ratio correlated with lateral e' (r = -0.568; P = 0.004) and E/e' ratio (r = 0.428; P = 0.037) in controls and with LVMI (r = 0.252; P = 0.022) and E/e' ratio (r = 0.269; P = 0.014) in HDP. Although the current data are not able to infer causality, they confirm the intimate relationship between the maternal cardiovascular system and angiogenic markers that are used both to diagnose and indicate the severity of HDP. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Prediction of preterm birth in growth-restricted and appropriate-for-gestational-age infants using maternal PlGF and the sFlt-1/PlGF ratio-A prospective study.

To assess the utility of placental growth factor (PlGF) levels and the soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio to predict preterm birth (PTB) for infants with fetal growth restriction (FGR) and those appropriate for gestational age (AGA). Prospective, observational cohort study. Tertiary maternity hospital in Australia. There were 320 singleton pregnancies: 141 (44.1%) AGA, 83 (25.9%) early FGR (<32+0  weeks) and 109 (30.0%) late FGR (≥32+0  weeks). Maternal serum PlGF and sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. Low maternal PlGF levels and elevated sFlt-1/PlGF ratio were defined as <100 ng/L and >5.78 if <28 weeks and >38 if ≥28 weeks respectively. Cox proportional hazards models were used. The analysis period was defined as the time from the first measurement of PlGF and sFlt-1/PlGF ratio to the time of birth or censoring. The primary study outcome was overall PTB. The relative risks (RR) of birth within 1, 2 and 3 weeks and for medically indicated and spontaneous PTB were also ascertained. The early FGR cohort had lower median PlGF levels (54 versus 229 ng/L, p < 0.001) and higher median sFlt-1 levels (2774 ng/L versus 2096 ng/L, p < 0.001) and sFlt-1/PlGF ratio higher (35 versus 10, p < 0.001). Both PlGF <100 ng/L and elevated sFlt-1/PlGF ratio were strongly predictive for PTB as well as PTB within 1, 2 and 3 weeks of diagnosis. For both FGR and AGA groups, PlGF <100 ng/L or raised sFlt-1/PlGF ratio were strongly associated with increased risk for medically indicated PTB. The highest RR was seen in the FGR cohort when PlGF was <100 ng/L (RR 35.20, 95% CI 11.48-175.46). Low maternal PlGF levels and elevated sFlt-1/PlGF ratio are potentially useful to predict PTB in both FGR and AGA pregnancies.

Maternal serum soluble fms-like tyrosine kinase-1–to–placental growth factor ratio distinguishes growth-restricted from non–growth-restricted small-for-gestational-age fetuses

Fetal growth restriction secondary to chronic placental insufficiency is a major cause of perinatal morbidity and mortality. A significant proportion of fetuses with fetal growth restriction are small for gestational age, defined as a birthweight of ≤10th percentile. However, not all small-for-gestational-age fetuses are growth restricted. Some are constitutionally small and otherwise healthy. It is important to distinguish between small-for-gestational-age fetuses with and without fetal growth restriction to ensure appropriate interventions in small-for-gestational-age fetuses with fetal growth restriction and to minimize unnecessary interventions in healthy small-for-gestational-age fetuses. The maternal serum ratio of soluble fms-like tyrosine kinase-1 and placental growth factor is an indicator of placental insufficiency in the latter half of pregnancy. As such, the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio may be a clinically useful tool to distinguish between small-for-gestational-age fetuses with and without fetal growth restriction. This study aimed to determine whether the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio can distinguish between small-for-gestational-age fetuses with and without fetal growth restriction with a birthweight of ≤10th percentile. A retrospective audit of 233 singleton pregnancies delivering an infant with a birthweight of ≤10th percentile corrected for gestational age with an antenatal maternal serum soluble fms-like tyrosine kinase-1-to-placental growth factor result was performed. Fetal growth restriction was defined as a birthweight of ≤10th percentile with an umbilical artery pulsatility index of >95th percentile, fetal middle cerebral artery pulsatility index of <5th percentile, amniotic fluid index of <6 cm, and/or cerebroplacental ratio of <1st percentile. The soluble fms-like tyrosine kinase-1-to-placental growth factor ratios before delivery between fetuses with and without fetal growth restriction (121 [fetal growth restriction] vs 112 [no fetal growth restriction]) were compared. The Student t test and Fisher exact test were used to compare cases and controls. The Mann-Whitney U test, linear regression analysis, and Spearman correlation coefficient (Rho) were used to examine associations between the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio and fetal outcomes to determine whether the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio served as a prognostic marker of fetal growth restriction severity. The mean soluble fms-like tyrosine kinase-1-to-placental growth factor ratio was increased in fetal growth restriction cases compared with non-fetal growth restriction controls (234.3±25.0 vs 67.4±7.7, respectively; P<.0001). When controlling for preeclampsia, which is associated with placental insufficiency, fetal growth restriction cases still demonstrated an independent increase in the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio (effect size, 0.865; 95% confidence interval, 0.509-1.220; P<.001). The soluble fms-like tyrosine kinase-1-to-placental growth factor ratio was negatively correlated with birthweight percentiles in pregnancies delivering an infant with a birthweight of ≤10th percentile (r=-0.3565; P<.0001). This association was maintained for fetuses with fetal growth restriction (r=-0.2309; P<.05), whereas fetuses without fetal growth restriction had no significant correlation between the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio and neonatal birthweight percentiles. The soluble fms-like tyrosine kinase-1-to-placental growth factor ratio was significantly higher in small-for-gestational-age fetuses with fetal growth restriction than small-for-gestational-age fetuses without fetal growth restriction, independent of preeclampsia. Furthermore, the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio was negatively correlated with fetal growth restriction birthweight percentiles, suggesting that it may be a clinical measure of fetal growth restriction severity. Therefore, the ratio may usefully delineate fetal growth restriction from constitutionally small but otherwise healthy fetuses antenatally, allowing for timely interventions in small-for-gestational-age cases with fetal growth restriction and unnecessary interventions to be minimized in small-for-gestational-age cases without fetal growth restriction.