The diagnostic value of angiogenic and antiangiogenic factors in differential diagnosis of preeclampsia

Preeclampsia pathogenesis and prediction - where are we now: the focus on the role of galectins and miRNAs

Preeclampsia is a complex, progressive multisystem hypertensive disorder during pregnancy that significantly contributes to increased maternal and perinatal morbidity and mortality. Two screening algorithms are in clinical use for detecting preeclampsia: first-trimester screening, which has been developed and validated for predicting early-onset preeclampsia but is less effective for late-onset disease; and the sFlt-1:PlGF biomarker ratio (soluble tyrosine kinase and placental growth factor) used in suspected cases of preeclampsia. This ratio has a high negative predictive value, allowing for the reliable exclusion of the disease. Both of these screening tests have not met expectations. This review attempts to summarize the current knowledge on the pathogenesis and prediction of preeclampsia and to draw attention to novel biomarkers with a focus on microRNAs and galectins. Although these molecules belong to two distinct biological classes, they functionally converge in regulating placental and immune pathways. Ample evidence supports their involvement in the molecular mechanisms underlying preeclampsia. Based on current knowledge, galectin-13, C19MC members, and miRNA-210 are associated with the trophoblast/placenta and conditions of placental ischemia or hypoxia. Their levels differ significantly in pregnant women at risk of preeclampsia as early as the late first and early second trimester, making them potential markers for predicting preeclampsia.

Assessment of a salivary cfRNA biomarker panel to predict preeclampsia

OBJECTIVE

Placental proteins, including placental alkaline phosphatase (PLAP), soluble fms-like tyrosine kinase-1 (sFLT-1) and placental growth factor (PlGF), are quantifiable in maternal saliva and show promise as predictive biomarkers for the development of pregnancy complications including preeclampsia. We aimed to develop a more comprehensive cell-free RNA saliva based placental biomarker panel with the addition of vascular endothelial growth factor A (VEGFA), soluble endoglin (sENG), pregnancy-associated plasma protein A (PAPPA), and sFLT-1:PlGF to predict preeclampsia prior to the onset of symptoms.

METHODS

In this prospective, observational study, 127 asymptomatic, pregnant women provided whole saliva samples in either the second (n = 55) or third (n = 72) trimesters. Saliva samples underwent RNA extraction and droplet digital PCR quantification for the six biomarkers. Clinical outcomes were correlated to salivary profiles.

RESULTS

Nine participants (7 %) were diagnosed with preeclampsia. All genes in the biomarker panel were detected. The sFLT-1:PlGF ratio was significantly higher (Mann-Whitney U test, p = 0.032) in women assessed in the third trimester who developed preeclampsia compared to women who did not. Area under the receiver operating curve for all 6 quantified placental markers had a predictive value of 68.4 % for the future onset of preeclampsia. Mean latency from sampling to diagnosis was 10.7 weeks.

DISCUSSION

A cell-free RNA saliva-based gene panel may predict preeclampsia in asymptomatic women. Specifically, elevated salivary sFLT-1:PlGF in the third trimester is predictive of impending disease onset. This represents an important opportunity to leverage non-invasive saliva screening to better identify women at risk for developing preeclampsia.

Placental Biomarker Testing for Evaluation of Suspected Preeclampsia

BACKGROUND

Worldwide, hypertensive disorders of pregnancy (HDP) are a leading cause of maternal and neonatal morbidity and mortality (Semin Perinatol 2009;33:130-7). This is especially true in the United States where preeclampsia is a leading cause of premature births (Hypertens Pregnancy 2016;35:510-9 and Lancet 2008;371:164-75). Moreover, this disorder is costly due to the financial burden of the health services needed to care for mothers with preeclampsia and their very often preterm infants (Am J Obstet Gynecol 2017;217:235-6). Recently, placental biomarkers have been shown to aid in assessment of the risk of severe preeclampsia. In 2023, the FDA approved the use of soluble feline McDonough sarcoma (fms)-like tyrosine kinase-1 to placental growth factor ratio (sFlt-1/PlGF) as an additional tool for preeclampsia risk assessment between 23 and 35 weeks' gestation in high-risk patients in the United States. Use of these biomarkers will improve maternal and fetal/neonatal outcomes and may assist in decreasing the healthcare burden of these patients by adding to risk assessment and the current diagnosis and management of pregnancies with HDP.

CONTENT

The pathophysiology of preeclampsia stems from abnormal placentation that results in an imbalance of pro- and antiangiogenic factors leading to endothelial and vascular dysfunction and the clinical syndrome of preeclampsia (J Clin Invest 2003;111:649-58). The role of the sFlt-1/PlGF in the prediction of progression to preeclampsia has been demonstrated in multiple studies.

SUMMARY

The goal of this review is to demonstrate the role of placental biomarkers (sFlt-1 and PlGF) in the pathophysiology of preeclampsia, with an emphasis on clinical applications and cost-effectiveness in the United States, using real-world applications as examples.

Sphingosine-1-Phosphate, a Marker of Endothelial Injury and Disease Severity in Preeclampsia

BACKGROUND

Preeclampsia is a hypertensive pregnancy disorder marked by endothelial damage. Healthy endothelium is covered by a protective glycocalyx layer, which, when degraded, releases detectable products into the blood. Sphingosine-1-phosphate (S1P) is a cardiovascular biomarker involved in glycocalyx preservation, linked to placentation and preeclampsia development. The study aimed to test the hypothesis that plasma S1P is altered alongside glycocalyx degradation products in severe preeclampsia compared with controls.

METHODS

We included 121 females: 41 with severe preeclampsia requiring treatment in the intensive care unit, 40 with preeclampsia but no need of intensive care unit treatment, and 40 with normotensive pregnancies. Plasma levels of S1P and glycocalyx degradation products-hyaluronic acid, SDC-1 (syndecan-1), and HSPG2 (heparan sulfate proteoglycan-2)-were analyzed from blood samples taken within 27 hours postpartum.

RESULTS

Postpartum plasma S1P was significantly lower in the intensive care unit cohort compared with both preeclampsia controls and normotensive controls (P<0.001). Hyaluronic acid and SDC-1 levels were elevated in the intensive care unit group versus normotensive controls (P=0.009 and P=0.023), while HSPG2 was lower (P<0.001). Plasma S1P correlated with hyaluronic acid and blood pressure.

CONCLUSION

Intensive care patients with severe preeclampsia have lower plasma S1P levels and higher concentrations of glycocalyx degradation products, indicating more pronounced endothelial damage. These findings suggest that S1P is associated with preeclampsia severity and may serve as a biomarker to assess vascular damage in this patient population. Further studies are needed to explore the potential role of S1P in long-term cardiovascular risk assessment for patients with preeclampsia.

Prevention of Pre-Eclampsia: Modern Strategies and the Role of Early Screening

Background: Pre-eclampsia (PE) remains a leading cause of maternal and perinatal morbidity and mortality worldwide. Early detection and risk stratification are critical for improving pregnancy outcomes. This review aims to summarize current advancements in PE screening, including clinical risk factors, biomarkers, imaging techniques, and predictive models. Methods: A comprehensive literature search was conducted using PubMed, Scopus, Web of Science, and Google Scholar to identify relevant studies on PE screening and prediction. Peer-reviewed original studies, systematic reviews, and meta-analyses published in English were included, while case reports and conference abstracts were excluded. Results: Traditional screening methods rely on maternal history and clinical risk factors, while emerging approaches incorporate biochemical markers and ultrasound parameters to enhance predictive accuracy. Machine learning models and artificial intelligence (AI)-driven algorithms are being explored for improved risk stratification. However, challenges such as data heterogeneity, lack of external validation, and integration into clinical practice remain. Conclusions: Advances in PE screening hold promise for early identification and targeted prevention strategies. Future research should focus on validating predictive models in diverse populations, integrating AI with traditional screening methods, and developing personalized approaches to reduce PE-associated complications.

Real-world evidence for the utility of serum soluble fms-like tyrosine kinase 1/placental growth factor test for routine clinical evaluation of hospitalized women with hypertensive disorders of pregnancy

BACKGROUND

An imbalance of the antiangiogenic factor, soluble fms-like tyrosine kinase-1, and proangiogenic factor, placental growth factor, in the circulation is a reliable predictor for the development of preeclampsia with severe features and related adverse outcomes. In 2023, the US Food and Drug Administration approved a serum soluble fms-like tyrosine kinase-1/placental growth factor test at a cutoff of 40 to aid in the risk assessment of women hospitalized for hypertensive disorders of pregnancy for the progression to preeclampsia with severe features between 23 and 35 weeks.

OBJECTIVE

This study aimed to generate real-world evidence for clinical utility for serum soluble fms-like tyrosine kinase-1/placental growth factor test when made available to clinicians in a timely fashion as an aid in risk stratification of development of preeclampsia with severe features within 2 weeks of testing among hospitalized patients with hypertensive disorders of pregnancy.

STUDY DESIGN

Hospitalized patients with hypertensive disorders of pregnancy between 23 weeks to 34 weeks and 6 days of gestation were prospectively studied from June 2023 to January 2024 after the implementation of serum soluble fms-like tyrosine kinase-1/placental growth factor testing into routine clinical practice. Serum samples were obtained from patients via venipuncture and analyzed on an automated immunoassay platform (placental growth factor and soluble fms-like tyrosine kinase-1 assays; Thermo Fisher Scientific). Before implementation, physicians were educated on appropriate use and management guidelines on the basis of biomarkers but made pragmatic management decisions independently. Results of soluble fms-like tyrosine kinase-1/placental growth factor tests were available to clinicians within 24 hours of venipuncture. The association between soluble fms-like tyrosine kinase-1/placental growth factor ≥40 and progression to preeclampsia with severe features and adverse maternal/perinatal outcomes were assessed.

RESULTS

Of the 65 patient encounters, 36 had a soluble fms-like tyrosine kinase-1/placental growth factor <40 (55.4%). The rate of delivery for indications related to hypertensive disorders of pregnancy within 2 weeks was significantly lower among encounters with a low ratio vs high ratio (2/36 [5.6%] vs 21/29 [72.4%]) even after controlling for relevant confounders (adjusted hazard ratio, 7.52; 95% confidence interval, 3.05-18.54; P<.001). A diagnosis of preeclampsia with severe features within 2 weeks of testing was also less likely among the encounters with soluble fms-like tyrosine kinase-1/placental growth factor ratio <40 when compared with soluble fms-like tyrosine kinase-1/placental growth factor ratio ≥40 (2/36 [5.6%] vs 23/29 [79.3%], P<.001; positive predictive value of 79% [95% confidence interval, 0.65-0.94] and negative predictive value of 0.94 [95% confidence interval, 0.87-1.00]). The positive and negative likelihood ratios for the development of preeclampsia with severe features within 2 weeks of testing were 6.13 and 0.09, respectively. Encounters with a soluble fms-like tyrosine kinase-1/placental growth factor ratio <40 were less likely to experience a maternal or fetal adverse event as compared with encounters with soluble fms-like tyrosine kinase-1/placental growth factor ratio ≥40 (3/36 [8.3%] vs 10/29 [34.5%], P=.01). Among 36 encounters involving low soluble fms-like tyrosine kinase-1/placental growth factor values, 22 had had equivocal clinical or laboratory criteria resembling preeclampsia at presentation but were expectantly managed on the basis of biomarkers, and none developed preeclampsia with severe features or adverse outcomes at 2 weeks. The median latency defined as days between biomarker measurement and delivery in patients with a low biomarker ratio was 33 (interquartile ratio, 23-47) vs 7 (interquartile ratio, 4-14) days among patients with a high ratio (P<.001). Corticosteroid use within 2 weeks was also significantly reduced in the low biomarker group when compared with the high biomarker group (8/35 [22.9%] vs 24/29 [82.8%], P<.001).

CONCLUSION

In this study, the incorporation of soluble fms-like tyrosine kinase-1/placental growth factor ratio into clinical practice serves as a dependable supplement in assessing risk for progression to preeclampsia with severe features and adverse outcomes in patients with hypertensive disorders of pregnancy in the United States. Among patients with a low ratio, pregnancy may be prolonged, which results in better neonatal outcomes without harm to the mother.

Angiogenic factors alone or in combination with ultrasound Doppler criteria for risk classification among late-onset small fetuses with or without pre-eclampsia

OBJECTIVE

To investigate the prognostic value of maternal angiogenic factors in late-onset small fetuses, alone or in combination with the ultrasound and Doppler parameters currently used for the classification of low-risk small-for-gestational-age (SGA) fetuses or high-risk fetal growth restriction (FGR), overall and according to the presence or absence of pre-eclampsia.

METHODS

This was a prospective cohort study of women with a singleton pregnancy with a diagnosis of late-onset fetal smallness (defined as birth weight < 10th centile) and a gestational age of ≥ 34 weeks at delivery. Ultrasound assessment of estimated fetal weight (EFW) and Doppler assessment of uterine artery pulsatility index (UtA-PI) and cerebroplacental ratio (CPR) were performed every 1-2 weeks. Biochemical analysis of the angiogenic factors placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) in maternal peripheral venous blood samples was performed using enzyme-linked immunosorbent assay within 1-2 weeks after diagnosis of SGA or FGR. The primary outcome was adverse perinatal outcome, defined as a composite of emergency Cesarean section for non-reassuring fetal status, metabolic acidosis (umbilical artery pH < 7.0), neonatal unit admission and/or perinatal death. The predictive value of EFW < 3rd centile, Doppler parameters (UtA-PI > 95th centile and CPR < 5th centile) and sFlt-1/PlGF ratio > 95th centile, alone or in combination, was assessed using logistic regression analysis in the overall population and stratified by presence or absence of pre-eclampsia developing at any time before delivery.

RESULTS

Among the 602 included cases, 91 (15.1%) developed pre-eclampsia and 511 (84.9%) did not. In the overall study population, all parameters were associated independently with adverse perinatal outcome: EFW < 3rd centile (adjusted odds ratio (aOR), 2.58 (95% CI, 1.67-4.00)), UtA-PI > 95th centile (aOR, 1.92 (95% CI, 1.25-2.94)), CPR < 5th centile (aOR, 2.35 (95% CI, 1.46-3.78)) and sFlt-1/PlGF ratio > 95th centile (aOR, 1.71 (95% CI, 1.09-2.69)). Only sFlt-1/PlGF ratio > 95th centile was associated independently with adverse perinatal outcome in cases with pre-eclampsia, whereas in those without pre-eclampsia, only EFW < 3rd centile and CPR < 5th centile were associated independently with adverse perinatal outcome. In the overall population, the detection rate (DR) and false-positive rate for adverse perinatal outcome were, respectively: 39.8% (95% CI, 31.7-47.9%) and 16.9% (95% CI, 10.7-23.1%) for sFlt-1/PlGF ratio > 95th centile alone; 86.8% (95% CI, 83.4-90.2%) and 61.9% (95% CI, 57.1-66.7%) for a combined model of EFW < 3rd centile, UtA-PI > 95th centile and CPR < 5th centile; 81.3% (95% CI, 77.3-85.3%) and 52.3% (95% CI, 47.1-57.5%) for a combined model of EFW < 3rd centile and sFlt-1/PlGF ratio > 95th centile; and 88.5% (95% CI, 85.4-91.6%) and 64.5% (95% CI, 59.8-69.2%) for a combined model including all the abovementioned observed parameters.

CONCLUSIONS

sFlt-1/PlGF ratio alone had a low predictive value for adverse perinatal outcome, but when combined with EFW, its predictive performance was similar to that of EFW combined with Doppler parameters. Combining sFlt-1/PlGF ratio with EFW and Doppler criteria achieved the highest DR for adverse perinatal outcome, and additionally, might help to identify imminent pre-eclampsia in pregnancies complicated by fetal smallness. These findings support the use of angiogenic factors as an additional criterion to those currently used for identifying high-risk FGR among late-onset small fetuses, but do not support their use as a standalone biomarker. © 2025 International Society of Ultrasound in Obstetrics and Gynecology.

Identification of hub genes, diagnostic model, and immune infiltration in preeclampsia by integrated bioinformatics analysis and machine learning

PURPOSE

This study aimed to identify novel biomarkers for preeclampsia (PE) diagnosis by integrating Weighted Gene Co-expression Network Analysis (WGCNA) with machine learning techniques.

PATIENTS AND METHODS

We obtained the PE dataset GSE25906 from the gene expression omnibus (GEO) database. Analysis of differentially expressed genes (DEGs) and module genes with Limma and Weighted Gene Co-expression Network analysis (WGCNA). Candidate hub genes for PE were identified using machine learning. Subsequently, we used western-blotting (WB) and real-time fluorescence quantitative (qPCR) to verify the expression of F13A1 and SCCPDH in preeclampsia patients. Finally, we estimated the extent of immune cell infiltration in PE samples by employing the CIBERSORT algorithms.

RESULTS

Our findings revealed that F13A1 and SCCPDH were the hub genes of PE. The nomogram and two candidate hub genes had high diagnostic values (AUC: 0.90 and 0.88, respectively). The expression levels of F13A1 and SCCPDH were verified by WB and qPCR. CIBERSORT analysis confirmed that the PE group had a significantly larger proportion of plasma cells and activated dendritic cells and a lower portion of resting memory CD4 + T cells.

CONCLUSION

The study proposes F13A1 and SCCPDH as potential biomarkers for diagnosing PE and points to an improvement in early detection. Integration of WGCNA with machine learning could enhance biomarker discovery in complex conditions like PE and offer a path toward more precise and reliable diagnostic tools.

Advancing diagnosis and early risk assessment of preeclampsia through noninvasive cell-free DNA methylation profiling

BACKGROUND

Aberrant embryo implantation and suboptimal placentation can lead to (severe) complications such as preeclampsia and fetal growth restriction later in pregnancy. Current identification of high-risk pregnancies relies on a combination of risk factors, biomarkers, and ultrasound examinations, a relatively inaccurate approach. Previously, aberrant DNA methylation due to placental hypoxia has been identified as a potential marker of placental insufficiency and, hence, potential (future) pregnancy complications. The goal of the Early Prediction of prEgnancy Complications Testing, or the ExPECT study, is to validate a genome-wide, cell-free DNA (cfDNA) methylation strategy to diagnose preeclampsia accurately. More importantly, the predictive potential of this strategy is also explored to reliably identify high-risk pregnancies early in gestation. Furthermore, a longitudinal study was conducted, including sequential blood samples from pregnant individuals experiencing both uneventful and complicated gestations, to assess the methylation dynamics of cfDNA throughout these pregnancies. A significant strength of this study is its enzymatic digest, which enriches CpG-rich regions across the genome without the need for proprietary reagents or prior selection of regions of interest. This makes it useful for the cost-effective discovery of novel markers.

RESULTS

Investigation of methylation patterns throughout pregnancy showed different methylation trends between unaffected and affected pregnancies. We detected differentially methylated regions (DMRs) in pregnancies complicated with preeclampsia as early as 12 weeks of gestation, with distinct differences in the methylation profile between early and late pregnancy. Two classification models were developed to diagnose and predict preeclampsia, demonstrating promising results on a small set of validation samples.

CONCLUSIONS

This study offers valuable insights into methylation changes at specific genomic regions throughout pregnancy, revealing critical differences between normal and complicated pregnancies. The power of noninvasive cfDNA methylation profiling was successfully proven, suggesting the potential to integrate this noninvasive approach into routine prenatal care.

Relationship between maternal serum sFlt-1 level and placenta accreta spectrum disorders in the third trimester

PURPOSE

This study aims to evaluate whether the third-trimester soluble fms-like tyrosine kinase-1 (sFlt-1) serum levels could be related to placenta accreta spectrum (PAS) disorders and the severity of postpartum blood loss.

METHODS

This was a nested case-control study which compared serum sFlt-1 level between gravid women with or without PAS disorders. Spearman correlation analysis was conducted to explore the relationship between sFlt-1 level and the volume of postpartum blood loss. Confounding factors were adjusted to avoid the impact on the results.

RESULTS

Sixty gravid women were enrolled: 36 women in the PAS group and 24 women in the non-PAS group. Women in the PAS group had a median sFlt-1 level of 9407.1 [2745.9-21,691.5] pg/ml, whereas women in the non-PAS group had a median sFlt-1 level of 25,779.2 [14317.1-35,626.7] pg/ml, (p < 0.001). The sFlt-1 level was negatively related to the volume of postpartum blood loss (r =  - 0.358, p = 0.041). After adjusting for maternal age and gestational age at blood taking, sFlt-1 level showed no significant relationship with PAS disorders (p = 0.245) and postpartum blood loss (p = 0.526).

CONCLUSION

Third-trimester sFlt-1 serum level is not independently associated with PAS disorders or postpartum blood loss after adjusting for confounding factors.

Prediction of adverse maternal and perinatal outcomes associated with pre-eclampsia and hypertensive disorders of pregnancy: a systematic review and meta-analysis

Background

Hypertensive disorders of pregnancy are a leading cause of maternal and perinatal morbidity and mortality. If women at high risk for developing complications could be identified early, level of care could be triaged, limited resources could be correctly allocated and targeted interventions to prevent complications could be implemented.

Methods

We updated a systematic review and meta-analysis and added single outcomes. Women with hypertensive disorders of pregnancy were included. Exposures were tests predicting adverse maternal and/or perinatal outcomes. We searched Medline, Embase, CINAHL, and Cochrane library from January 2016-February 2024. We included studies identified from the previous review. We calculated effect measures. For similar predictive tests and outcomes, area under the receiver-operating-characteristic curve (AUROC) were pooled. This study was registered by PROSPERO: CRD42022336368.

Findings

Of the 2898 studies identified, 80 were included. Thirty were added from the previous review resulting in 110 included studies with 506,178 women. Despite more than 1500 tests being performed, most outcomes could not be pooled due to heterogeneity in populations, tests, and outcome definitions. For maternal outcomes, only studies reporting on the Pre-eclampsia Integrated Estimate of RiSk (fullPIERS) model could be pooled. For the composite outcome within 48-h the AUROC was 0.78 (95% CI 0.71-0.86, N = 8). There was significant heterogeneity (I 2  = 95.7%). For perinatal outcomes, data were pooled for pulsatility index in the umbilical artery and soluble FMS-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio. Biomarkers like the sFlt-1/PlGF ratio showed promising predictive performance for some outcomes but were not externally validated.

Interpretation

Despite including over 100 studies with more than 1500 predictors, we were unable to pool any single maternal outcomes and only a few individual perinatal outcomes. The fullPIERS model was externally validated, showing moderate accuracy which varied across studies and should be validated in each new population. Angiogenic biomarkers showed promise but need validation. Future studies should use standardized outcome measures and validate promising tests.

Funding

VB is supported by the Swedish Research Council, Grant number 2020-01481. University of Gothenburg.

The sFlt-1/PlGF-ratio and the risk of preeclampsia-related adverse outcomes in subsequent pregnancies with signs and symptoms of a preeclampsia

OBJECTIVES

This study characterizes the outcome of two subsequent pregnancies with suspected preeclampsia (PE). We investigated the diagnostic accuracy of clinical signs, Doppler examinations, and the soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF)-ratio to predict PE-related adverse outcomes (AO). The sFlt-1/PlGF-ratio of the first pregnancy was compared to the outcome of the subsequent pregnancy.

STUDY DESIGN

A total of 1928 patients at risk for preeclampsia were screened, of them 1117 were eligible for inclusion. Of these, 84 women presented with suspected PE in two subsequent pregnancies.

OUTCOME MEASURES

Diagnostic accuracy of clinical markers was assessed. Associations between the sFlt-1/PlGF-ratio in the first and the odds of an AO in the subsequent pregnancy were investigated with logistic regression.

RESULTS

The prevalence of AOs decreased from 27.4 % in the first to 17.9 % in the second pregnancy. Comparison of the accuracy of the different clinical markers for an AO showed a high specificity for an sFlt-1/PlGF-ratio at the cut-off of ≥ 85 in both pregnancies (81.3 %, 95 % CI 63.6-92.8 vs 92.6 %,95 % CI 83.7-97.6), but a lower sensitivity in the second pregnancy (92.9 %, 95 % CI 66.1-99.8 vs 33.3%, 95 % CI 11.8-61.6). An elevated sFlt-1/PlGF-ratio in the first did not increase the odds of an AO in the subsequent pregnancy.

CONCLUSIONS

The prevalence of AOs decreases in subsequent pregnancies. Our finding that the sFlt-1/PlGF-ratio of the first was not related to the outcome of the subsequent pregnancy suggests that angiogenic markers are only a within-pregnancy short-term tool to assess AOs.

sFlt1/PlGF among patients with suspected preeclampsia when considering hypertensive status

BACKGROUND

In high-resource settings, biomarkers of angiogenic balance, such as the soluble fms-like tyrosine kinase-1 (sFlt1)/placental growth factor (PlGF) ratio, have been studied extensively to aid in evaluation of patients with suspected preeclampsia (PE), and have been incorporated into the 2021 International Society for the Study of Hypertension in Pregnancy definition of PE. The utility in under-resourced settings has not been as well characterized.

OBJECTIVE

This analysis sought to identify the role of the sFlt1/PlGF ratio in the evaluation of patients with or without hypertension who are suspected of having PE without other diagnostic information.

STUDY DESIGN

This is a secondary analysis of a prior prospective study of patients who were presented with suspected PE at ≥20+0 weeks' gestation at a single academic tertiary care center. Patients were recruited in the parent study from July 2009 to June 2012. In the original study, clinicians were masked to biomarker results, and patients were followed by chart review. In this analysis, the performance of the sFlt1/PlGF ratio (≤38, >38, or >85) was assessed alone in identifying both hypertensive and non-hypertensive patients at risk of evolving into PE with severe features (PE-SF; American College of Obstetricians and Gynecologists' definition) within two weeks of the triage visit (PE-SF2). Hypertension was defined as a blood pressure (BP)≥140/90 mmHg.

RESULTS

There were 1043 patients included in the analysis; of whom, 579 (55.5%) and 464 (44.5%) presented with or without hypertension, respectively. In triage, 332 (75.4%) of hypertensive patients presented due to BP concerns, and the remainder were evaluated due to other features (new-onset headache, proteinuria, or edema). On triage evaluation, 66.8% of all patients had a normal sFlt1/PlGF ratio ≤38, and 17.0% had an elevated ratio >85. Among hypertensive patients, a sFlt1/PlGF ratio ≤38 was a good rule-out test for PE-SF2 (negative likelihood ratio [LR-] of 0.15), and a ratio >85 was a good rule-in test (positive likelihood ratio [LR+] of 5.75). Among normotensive patients, sFlt1/PlGF was useful as a rule-in test for ratio >38 (LR+ 5.13) and >85 (LR+ 12.80). Stratified by gestational age, sFlt1/PlGF continued to be a good rule in and good rule out test at <35 weeks among those with hypertension but did not have good test performance ≥35 weeks. sFlt1/PlGF had a good test performance as a rule in test for >85 regardless of gestational age. In triage, 4.3% (30/693) of patients with sFlt1/PlGF ratio <38 had concurrent laboratory evidence of PE, compared with 15.9% (28/176) patients with ratio >85.

CONCLUSION

These findings support the potential for the use of sFlt1/PlGF and BP measurement alone in resource-limited settings where other laboratory tests or clinical expertise are unavailable for risk stratification. Performance of the biomarker varied by the presence of hypertension and gestational age.

Prevention of Pregnancy Complications Using a Multimodal Lifestyle, Screening, and Medical Model

Prevention of pregnancy complications related to the "great obstetrical syndromes" (preeclampsia, fetal growth restriction, spontaneous preterm labor, and stillbirth) is a global research and clinical management priority. These syndromes share many common pathophysiological mechanisms that may contribute to altered placental development and function. The resulting adverse pregnancy outcomes are associated with increased maternal and perinatal morbidity and mortality and increased post-partum risk of cardiometabolic disease. Maternal nutritional and environmental factors are known to play a significant role in altering bidirectional communication between fetal-derived trophoblast cells and maternal decidual cells and contribute to abnormal placentation. As a result, lifestyle-based interventions have increasingly been recommended before, during, and after pregnancy, in order to reduce maternal and perinatal morbidity and mortality and decrease long-term risk. Antenatal screening strategies have been developed following extensive studies in diverse populations. Multivariate preeclampsia screening using a combination of maternal, biophysical, and serum biochemical markers is recommended at 11-14 weeks' gestation and can be performed at the same time as the first-trimester ultrasound and blood tests. Women identified as high-risk can be offered prophylactic low dose aspirin and monitored with angiogenic factor assessment from 22 weeks' gestation, in combination with clinical assessment, serum biochemistry, and ultrasound. Lifestyle factors can be reassessed during counseling related to antenatal screening interventions. The integration of lifestyle interventions, pregnancy screening, and medical management represents a conceptual advance in pregnancy care that has the potential to significantly reduce pregnancy complications and associated later life cardiometabolic adverse outcomes.

Significance of the sFlt-1/PlGF Ratio in Certain Cohorts - What Needs to be Considered?

The sFlt-1/PlGF ratio is an established tool in clinical practice, where it is part of a diagnostic algorithm and informs the prognosis of preeclampsia (PE). Maternal and gestational comorbidities can affect the performance of the sFlt-1/PlGF ratio and its constituent elements, and a good understanding of the potential pitfalls is required. The objective of this paper was to provide a current narrative review of the literature on the diagnostic and predictive performance of the sFlt-1/PlGF ratio in specific patient cohorts. Potential factors which can negatively affect the clinical interpretability and applicability of the sFlt-1/PlGF ratio include chronic kidney disease, twin pregnancy, and maternal obesity. Pathophysiological mechanisms related to these factors and disorders can result in different concentrations of sFlt-1 and/or PlGF in maternal blood, meaning that the use of standard cut-off values in specific cohorts can lead to errors. To what extent the cut-off values should be adapted in certain patient cohorts can only be clarified in large prospective cohort studies. This applies to the use of the ratio both for diagnosis and prognosis.

Reducing the Risk of Pre-Eclampsia in Women with Polycystic Ovary Syndrome Using a Combination of Pregnancy Screening, Lifestyle, and Medical Management Strategies

Polycystic ovary syndrome (PCOS) is a multisystem disorder that presents with a variety of phenotypes involving metabolic, endocrine, reproductive, and psychological symptoms and signs. Women with PCOS are at increased risk of pregnancy complications including implantation failure, miscarriage, gestational diabetes, fetal growth restriction, preterm labor, and pre-eclampsia (PE). This may be attributed to the presence of specific susceptibility features associated with PCOS before and during pregnancy, such as chronic systemic inflammation, insulin resistance (IR), and hyperandrogenism, all of which have been associated with an increased risk of pregnancy complications. Many of the features of PCOS are reversible following lifestyle interventions such as diet and exercise, and pregnant women following a healthy lifestyle have been found to have a lower risk of complications, including PE. This narrative synthesis summarizes the evidence investigating the risk of PE and the role of nutritional factors in women with PCOS. The findings suggest that the beneficial aspects of lifestyle management of PCOS, as recommended in the evidence-based international guidelines, extend to improved pregnancy outcomes. Identifying high-risk women with PCOS will allow targeted interventions, early-pregnancy screening, and increased surveillance for PE. Women with PCOS should be included in risk assessment algorithms for PE.

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, in vitro 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.

Immunologic aspects of preeclampsia

Preeclampsia is a syndrome with multiple etiologies. The diagnosis can be made without proteinuria in the presence of dysfunction of at least 1 organ associated with hypertension. The common pathophysiological pathway includes endothelial cell activation, intravascular inflammation, and syncytiotrophoblast stress. There is evidence to support, among others, immunologic causes of preeclampsia. Unlike defense immunology, reproductive immunology is not based on immunologic recognition systems of self/non-self and missing-self but on immunotolerance and maternal-fetal cellular interactions. The main mechanisms of immune escape from fetal to maternal immunity at the maternal-fetal interface are a reduction in the expression of major histocompatibility complex molecules by trophoblast cells, the presence of complement regulators, increased production of indoleamine 2,3-dioxygenase, activation of regulatory T cells, and an increase in immune checkpoints. These immune protections are more similar to the immune responses observed in tumor biology than in allograft biology. The role of immune and nonimmune decidual cells is critical for the regulation of trophoblast invasion and vascular remodeling of the uterine spiral arteries. Regulatory T cells have been found to play an important role in suppressing the effectiveness of other T cells and contributing to local immunotolerance. Decidual natural killer cells have a cytokine profile that is favored by the presence of HLA-G and HLA-E and contributes to vascular remodeling. Studies on the evolution of mammals show that HLA-E, HLA-G, and HLA-C1/C2, which are expressed by trophoblasts and their cognate receptors on decidual natural killer cells, are necessary for the development of a hemochorial placenta with vascular remodeling. The activation or inhibition of decidual natural killer cells depends on the different possible combinations between killer cell immunoglobulin-like receptors, expressed by uterine natural killer cells, and the HLA-C1/C2 antigens, expressed by trophoblasts. Polarization of decidual macrophages in phenotype 2 and decidualization of stromal cells are also essential for high-quality vascular remodeling. Knowledge of the various immunologic mechanisms required for adequate vascular remodeling and their dysfunction in case of preeclampsia opens new avenues of research to identify novel biological markers or therapeutic targets to predict or prevent the onset of preeclampsia.

Fluorescence lifetime imaging microscopy for early diagnosis and severity prediction of preeclampsia with Nile Blue probe

Preeclampsia (PE) is a common pregnancy complication and the leading cause of maternal and perinatal mortality. Unfortunately, the early diagnostic methods for PE are still rare. Fluorescence lifetime imaging (FLIM) technology has proven to be applicable for diagnosis of various diseases. Here, we explore the possibility of the FLIM technique for PE early diagnosis and severity prediction with Nile Blue probe as biosensor. 23 placental slices and 162 third-trimester-collected maternal peripheral blood serum samples were stained with Nile blue and imaged by FLIM system. Fluorescence lifetimes of the probe increased significantly as the disease worsened (p < 0.0001). Characterization of the probe showed an increasing tendency in lifetimes under lower polarity conditions and revealed that the reason for the lifetime differences in serum sample was polarity changes caused by abnormal lipid metabolism in serum. For early diagnosis, we investigated 42 12th-week-collected chronic hypertension (CH) serum samples and successfully distinguished PE patients from pregnant women. With the functions of measuring fluorescence lifetime and detecting polarity changes caused by an abnormal lipid microenvironment in maternal peripheral blood, FLIM technology, together with Nile Blue probe, presents a feasible and advantageous approach for PE early noninvasive diagnosis and severity prediction.

Longitudinal assessment of angiogenic markers in prediction of adverse outcome in women with confirmed pre-eclampsia

OBJECTIVES

Angiogenic marker assessment, such as the ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF), is known to be a useful tool in the prediction of pre-eclampsia (PE). However, evidence from surveillance strategies in pregnancies with a PE diagnosis is lacking. Therefore, we aimed to assess the predictive performance of longitudinal maternal serum angiogenic marker assessment for both maternal and perinatal adverse outcomes when compared to standard laboratory parameters in pregnancies with confirmed PE.

METHODS

This was a retrospective analysis of prospectively collected data from January 2013 to December 2020 at the Medical University of Vienna. The inclusion criteria were singleton pregnancy with confirmed PE and post-diagnosis maternal serum angiogenic marker assessment at a minimum of two timepoints. The primary outcome was the predictive performance of longitudinal sFlt-1 and PlGF assessment for adverse maternal and perinatal outcomes compared to conventional laboratory monitoring at the same time in pregnancies with confirmed PE. Composite adverse maternal outcome included intensive care unit admission, pulmonary edema, eclampsia and/or death. Composite adverse perinatal outcome included stillbirth, neonatal death, placental abruption, neonatal intensive care unit admission, intraventricular hemorrhage, necrotizing enterocolitis, respiratory distress syndrome and/or mechanical ventilator support.

RESULTS

In total, 885 post-diagnosis sFlt-1/PlGF ratio measurements were obtained from 323 pregnant women with confirmed PE. For composite adverse maternal outcome, the highest standalone predictive accuracy was obtained using maternal serum sFlt-1/PlGF ratio (area under the receiver-operating-characteristics curve (AUC), 0.72 (95% CI, 0.62-0.81)), creatinine (AUC, 0.71 (95% CI, 0.62-0.81)) and lactate dehydrogenase (LDH) levels (AUC, 0.73 (95% CI, 0.65-0.81)). Maternal platelet levels (AUC, 0.65 (95% CI, 0.55-0.74)), serum alanine aminotransferase (ALT) (AUC, 0.59 (95% CI, 0.49-0.69)) and aspartate aminotransferase (AST) (AUC, 0.61 (95% CI, 0.51-0.71) levels had poor standalone predictive accuracy. The best prediction model consisted of a combination of maternal serum LDH, creatinine levels and sFlt-1/PlGF ratio, which had an AUC of 0.77 (95% CI, 0.68-0.85), significantly higher than sFlt-1/PlGF ratio alone (P = 0.037). For composite adverse perinatal outcome, the highest standalone predictive accuracy was obtained using maternal serum sFlt-1/PlGF ratio (AUC, 0.82 (95% CI, 0.75-0.89)) and creatinine (AUC, 0.74 (95% CI, 0.67-0.80)) levels, sFlt-1/PlGF ratio being superior to creatinine alone (P < 0.001). Maternal serum LDH levels (AUC, 0.65 (95% CI, 0.53-0.74)), platelet count (AUC, 0.57 (95% CI, 0.44-0.67)), ALT (AUC, 0.58 (95% CI, 0.48-0.67)) and AST (AUC, 0.58 (95% CI, 0.48-0.67)) levels had poor standalone predictive accuracy. No combination of biomarkers was superior to maternal serum sFlt-1/PlGF ratio alone for prediction of composite adverse perinatal outcome (P > 0.05 for all).

CONCLUSIONS

In pregnancies with confirmed PE, longitudinal maternal serum angiogenic marker assessment is a good predictor of adverse maternal and perinatal outcomes and superior to some conventional laboratory parameters. Further studies should focus on optimal surveillance following diagnosis of PE. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Pulmonary phenotypes of bronchopulmonary dysplasia in the preterm infant

Bronchopulmonary dysplasia (BPD) remains the most common complication of premature birth, imposing a significant and potentially life-long burden on patients and their families. Despite advances in our understanding of the mechanisms that contribute to patterns of lung injury and dysfunctional repair, current therapeutic strategies remain non-specific with limited success. Contemporary definitions of BPD continue to rely on clinician prescribed respiratory support requirements at specific time points. While these criteria may be helpful in broadly identifying infants at higher risk of adverse outcomes, they do not offer any precise information regarding the degree to which each compartment of the lung is affected. In this review we will outline the different pulmonary phenotypes of BPD and discuss important features in the pathogenesis, clinical presentation, and management of these frequently overlapping scenarios.

Identification of novel first-trimester serum biomarkers for early prediction of preeclampsia

BACKGROUND

Preeclampsia (PE) is a leading cause of maternal and perinatal mortality and morbidity worldwide, but effective early prediction remains a challenge due to the lack of reliable biomarkers.

METHODS

Based on the extensive human biobank of our large-scale assisted reproductive cohort platform, the first-trimester serum levels of 48 cytokines, total immunoglobulins (Igs), anti-phosphatidylserine (aPS) antibodies, and several previously reported PE biomarkers [including placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and activin A] were measured in 34 women diagnosed with PE and 34 matched normotensive controls.

RESULTS

The PE group has significantly higher first-trimester serum levels of interleukin (IL)-2Rα, IL-9, tumor necrosis factor-β (TNF-β), RANTES, hepatocyte growth factor (HGF), total IgM, and total IgG, and aPS IgG optical density (OD) value, as well as lower first-trimester serum levels of PlGF and total IgA and aPS-IgG immune complexes (IC) OD value than the control group. Combining top five first-trimester serum biomarkers (total IgM, total IgG, PlGF, aPS IgG, and total IgA) achieved superior predictive value [area under the curve (AUC) and 95% confidence interval (CI) 0.983 (0.952-1.000), with a sensitivity of 100% and a specificity of 94.1%] for PE development compared to PlGF and PlGF/sFlt-1 independently [AUC and 95% CI 0.825 (0.726-0.924) and 0.670 (0.539-0.800), respectively].

CONCLUSION

We identified novel first-trimester serum biomarkers and developed an effective first-trimester prediction model using immune-related factors and PlGF for PE, which could facilitate the development of early diagnostic strategies and provide immunological insight into the further mechanistic exploration of PE.

Accuracy of placental growth factor alone or in combination with soluble fms-like tyrosine kinase-1 or maternal factors in detecting preeclampsia in asymptomatic women in the second and third trimesters: a systematic review and meta-analysis

OBJECTIVE

This study aimed to: (1) identify all relevant studies reporting on the diagnostic accuracy of maternal circulating placental growth factor) alone or as a ratio with soluble fms-like tyrosine kinase-1), and of placental growth factor-based models (placental growth factor combined with maternal factors±other biomarkers) in the second or third trimester to predict subsequent development of preeclampsia in asymptomatic women; (2) estimate a hierarchical summary receiver-operating characteristic curve for studies reporting on the same test but different thresholds, gestational ages, and populations; and (3) select the best method to screen for preeclampsia in asymptomatic women during the second and third trimester of pregnancy by comparing the diagnostic accuracy of each method.

DATA SOURCES

A systematic search was performed through MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform databases from January 1, 1985 to April 15, 2021.

STUDY ELIGIBILITY CRITERIA

Studies including asymptomatic singleton pregnant women at >18 weeks' gestation with risk of developing preeclampsia were evaluated. We included only cohort or cross-sectional test accuracy studies reporting on preeclampsia outcome, allowing tabulation of 2×2 tables, with follow-up available for >85%, and evaluating performance of placental growth factor alone, soluble fms-like tyrosine kinase-1- placental growth factor ratio, or placental growth factor-based models. The study protocol was registered on the International Prospective Register Of Systematic Reviews (CRD 42020162460).

METHODS

Because of considerable intra- and interstudy heterogeneity, we computed the hierarchical summary receiver-operating characteristic plots and derived diagnostic odds ratios, β, θi, and Λ for each method to compare performances. The quality of the included studies was evaluated by the QUADAS-2 tool.

RESULTS

The search identified 2028 citations, from which we selected 474 studies for detailed assessment of the full texts. Finally, 100 published studies met the eligibility criteria for qualitative and 32 for quantitative syntheses. Twenty-three studies reported on performance of placental growth factor testing for the prediction of preeclampsia in the second trimester, including 16 (with 27 entries) that reported on placental growth factor test alone, 9 (with 19 entries) that reported on the soluble fms-like tyrosine kinase-1-placental growth factor ratio, and 6 (16 entries) that reported on placental growth factor-based models. Fourteen studies reported on performance of placental growth factor testing for the prediction of preeclampsia in the third trimester, including 10 (with 18 entries) that reported on placental growth factor test alone, 8 (with 12 entries) that reported on soluble fms-like tyrosine kinase-1-placental growth factor ratio, and 7 (with 12 entries) that reported on placental growth factor-based models. For the second trimester, Placental growth factor-based models achieved the highest diagnostic odds ratio for the prediction of early preeclampsia in the total population compared with placental growth factor alone and soluble fms-like tyrosine kinase-1-placental growth factor ratio (placental growth factor-based models, 63.20; 95% confidence interval, 37.62-106.16 vs soluble fms-like tyrosine kinase-1-placental growth factor ratio, 6.96; 95% confidence interval, 1.76-27.61 vs placental growth factor alone, 5.62; 95% confidence interval, 3.04-10.38); placental growth factor-based models had higher diagnostic odds ratio than placental growth factor alone for the identification of any-onset preeclampsia in the unselected population (28.45; 95% confidence interval, 13.52-59.85 vs 7.09; 95% confidence interval, 3.74-13.41). For the third trimester, Placental growth factor-based models achieved prediction for any-onset preeclampsia that was significantly better than that of placental growth factor alone but similar to that of soluble fms-like tyrosine kinase-1-placental growth factor ratio (placental growth factor-based models, 27.12; 95% confidence interval, 21.67-33.94 vs placental growth factor alone, 10.31; 95% confidence interval, 7.41-14.35 vs soluble fms-like tyrosine kinase-1-placental growth factor ratio, 14.94; 95% confidence interval, 9.42-23.70).

CONCLUSION

Placental growth factor with maternal factors ± other biomarkers determined in the second trimester achieved the best predictive performance for early preeclampsia in the total population. However, in the third trimester, placental growth factor-based models had predictive performance for any-onset preeclampsia that was better than that of placental growth factor alone but similar to that of soluble fms-like tyrosine kinase-1-placental growth factor ratio. Through this meta-analysis, we have identified a large number of very heterogeneous studies. Therefore, there is an urgent need to develop standardized research using the same models that combine serum placental growth factor with maternal factors ± other biomarkers to accurately predict preeclampsia. Identification of patients at risk might be beneficial for intensive monitoring and timing delivery.

Modeling human ectopic pregnancies with trophoblast and vascular organoids

Ruptured ectopic pregnancy (REP), a pregnancy complication caused by aberrant implantation, deep invasion, and overgrowth of embryos in fallopian tubes, could lead to rupture of fallopian tubes and accounts for 4%-10% of pregnancy-related deaths. The lack of ectopic pregnancy phenotypes in rodents hampers our understanding of its pathological mechanisms. Here, we employed cell culture and organoid models to investigate the crosstalk between human trophoblast development and intravillous vascularization in the REP condition. Compared with abortive ectopic pregnancy (AEP), the size of REP placental villi and the depth of trophoblast invasion are correlated with the extent of intravillous vascularization. We identified a key pro-angiogenic factor secreted by trophoblasts, WNT2B, that promotes villous vasculogenesis, angiogenesis, and vascular network expansion in the REP condition. Our results reveal the important role of WNT-mediated angiogenesis and an organoid co-culture model for investigating intricate communications between trophoblasts and endothelial/endothelial progenitor cells.

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.

Comparison of the Soluble fms-Like Tyrosine Kinase 1/Placental Growth Factor Ratio Alone versus a Multi-Marker Regression Model for the Prediction of Preeclampsia-Related Adverse Outcomes after 34 Weeks of Gestation

INTRODUCTION

The objective of this retrospective study was to compare the predictive performance of the soluble fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio alone or in a multi-marker regression model for preeclampsia-related maternal and/or fetal adverse outcomes in women >34 weeks of gestation.

METHODS

We analyzed the data collected from 655 women with suspected preeclampsia. Adverse outcomes were predicted by multivariable and univariable logistic regression models. The outcome of patients was evaluated within 14 days after presentation with signs and symptoms of preeclampsia or diagnosed preeclampsia.

RESULTS

The full model integrating available, standard clinical information and the sFlt-1/PlGF ratio had the best predictive performance for adverse outcomes with an AUC of 72.6%, which corresponds to a sensitivity of 73.3% and specificity of 66.0%. The positive predictive value of the full model was 51.4%, and the negative predictive value was 83.5%. 24.5% of patients, who did not experience adverse outcomes but were classified as high risk by sFlt-1/PlGF ratio (≥38), were correctly classified by the regression model. The sFlt-1/PlGF ratio alone had a significantly lower AUC of 65.6%.

CONCLUSIONS

Integrating angiogenic biomarkers in a regression model improved the prediction of preeclampsia-related adverse outcomes in women at risk after 34 weeks of gestation.

SERPINA5 may promote the development of preeclampsia by disruption of the uPA/uPAR pathway

Preeclampsia (PE) is the leading cause of maternal and fetal morbidity or mortality but lacks reliable methods for early diagnosis. In a previous study, serum SERPINA5 levels were higher in women with PE before the clinical manifestation of the disease. This study aimed to evaluate the efficacy of SERPINA5 in predicting PE and investigate its role in trophoblast cell biology. A multicenter, 2-stage observational case-control study was performed to develop and validate an early predictive PE model based on SERPINA5, maternal characteristics, and inflammatory factors. To further understand the relationship between SERPINA5 and PE, SERPINA5 was overexpressed or knocked down in extravillous trophoblast cells (EVT) and a pregnant rat model. After development and initial validation, a model that combined SERPINA5 and inflammatory factors had a high predictive ability for PE before 20 weeks gestation with an AUC of 0.90 (95% CI 0.83-0.96). It also demonstrated that SERPINA5 inhibited primary EVT cell invasion by disrupting the urokinase-type plasminogen activator/urokinase-type plasminogen activator receptor (uPA/uPAR) pathway, in turn, is involved in the development of PE. In vivo experiments also proved that overexpression of SERPINA5 induced a PE-like syndrome (hypertension and proteinuria) in pregnant rats. Therefore, serum SERPINA5 is a promising early biomarker of PE, suggesting that it may be involved in placental development through its action on the uPA/uPAR system prior to the clinical manifestation of PE.

Toward a new taxonomy of obstetrical disease: improved performance of maternal blood biomarkers for the great obstetrical syndromes when classified according to placental pathology

BACKGROUND

The major challenge for obstetrics is the prediction and prevention of the great obstetrical syndromes. We propose that defining obstetrical diseases by the combination of clinical presentation and disease mechanisms as inferred by placental pathology will aid in the discovery of biomarkers and add specificity to those already known.

OBJECTIVE

To describe the longitudinal profile of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PlGF/sFlt-1 ratio throughout gestation, and to determine whether the association between abnormal biomarker profiles and obstetrical syndromes is strengthened by information derived from placental examination, eg, the presence or absence of placental lesions of maternal vascular malperfusion.

STUDY DESIGN

This retrospective case cohort study was based on a parent cohort of 4006 pregnant women enrolled prospectively. The case cohort of 1499 pregnant women included 1000 randomly selected patients from the parent cohort and all additional patients with obstetrical syndromes from the parent cohort. Pregnant women were classified into six groups: 1) term delivery without pregnancy complications (n=540; control); 2) preterm labor and delivery (n=203); 3) preterm premature rupture of the membranes (n=112); 4) preeclampsia (n=230); 5) small-for-gestational-age neonate (n=334); and 6) other pregnancy complications (n=182). Maternal plasma concentrations of PlGF and sFlt-1 were determined by enzyme-linked immunosorbent assays in 7560 longitudinal samples. Placental pathologists, masked to clinical outcomes, diagnosed the presence or absence of placental lesions of maternal vascular malperfusion. Comparisons between mean biomarker concentrations in cases and controls were performed by utilizing longitudinal generalized additive models. Comparisons were made between controls and each obstetrical syndrome with and without subclassifying cases according to the presence or absence of placental lesions of maternal vascular malperfusion.

RESULTS

1) When obstetrical syndromes are classified based on the presence or absence of placental lesions of maternal vascular malperfusion, significant differences in the mean plasma concentrations of PlGF, sFlt-1, and the PlGF/sFlt-1 ratio between cases and controls emerge earlier in gestation; 2) the strength of association between an abnormal PlGF/sFlt-1 ratio and the occurrence of obstetrical syndromes increases when placental lesions of maternal vascular malperfusion are present (adjusted odds ratio [aOR], 13.6 vs 6.7 for preeclampsia; aOR, 8.1 vs 4.4 for small-for-gestational-age neonates; aOR, 5.5 vs 2.1 for preterm premature rupture of the membranes; and aOR, 3.3 vs 2.1 for preterm labor (all P<0.05); and 3) the PlGF/sFlt-1 ratio at 28 to 32 weeks of gestation is abnormal in patients who subsequently delivered due to preterm labor with intact membranes and in those with preterm premature rupture of the membranes if both groups have placental lesions of maternal vascular malperfusion. Such association is not significant in patients with these obstetrical syndromes who do not have placental lesions.

CONCLUSION

Classification of obstetrical syndromes according to the presence or absence of placental lesions of maternal vascular malperfusion allows biomarkers to be informative earlier in gestation and enhances the strength of association between biomarkers and clinical outcomes. We propose that a new taxonomy of obstetrical disorders informed by placental pathology will facilitate the discovery and implementation of biomarkers as well as the prediction and prevention of such disorders.

Best Practices for Managing Postpartum Hypertension

Purpose of Review

Patients remain at risk for persistent and de novo postpartum hypertension related to pregnancy. This review aims to summarize the current definitions, clinical practices, and novel systems innovations and therapies for postpartum hypertension.

Recent Findings

Recent changes to the definitions of hypertension outside of pregnancy have not yet impacted definitions or management of hypertensive disorders of pregnancy (HDP), though research examining the implications of these new definitions on risks of developing HDP and the resultant sequelae is ongoing. The administration of diuretics has been shown to reduce postpartum hypertension among women with HDP. Widespread implementation of telemedicine models and remote assessment of ambulatory blood pressures has increased data available on postpartum blood pressure trajectories, which may impact clinical management. Additionally, policy changes such as postpartum Medicaid extension and an increasing emphasis on building bridges to primary care in the postpartum period may improve long-term outcomes for women with postpartum hypertension. Prediction models utilizing machine learning are an area of ongoing research to assist with risk assessment in the postpartum period.

Summary

The clinical management of postpartum hypertension remains focused on blood pressure control and primary care transition for cardiovascular disease risk reduction. In recent years, systemic innovations have improved access through implementation of new care delivery models. However, the implications of changing definitions of hypertension outside of pregnancy, increased data assessing blood pressure trajectories in the postpartum period, and the creation of new risk prediction models utilizing machine learning remain areas of ongoing research.

Biophysical Markers of Suspected Preeclampsia, Fetal Growth Restriction and the Two Combined—How Accurate They Are?

Objectives—To conduct a secondary analysis of prediction accuracy of biophysical markers for suspected Preeclampsia (PE), Fetal Growth Restriction (FGR) and the two combined near delivery in a Slovenian cohort. Methods—This was a secondary analysis of a database of a total 125 Slovenian pregnant women attending a high-risk pregnancy clinic due to suspected PE (n = 31), FGR (n = 16) and PE + FGR (n = 42) from 28–39 weeks gestation and their corresponding term (n = 21) and preterm (PTD, n = 15) controls. Data for Mean Arterial blood Pressure (MAP) and Uterine artery pulsatility index (UtA PI) estimated by Doppler sonography were extracted from the database of patients who were tested at admission to the high-risk clinic with the suspected complications. The reactive hyperemia index (RHI), and the Augmentation Index (AIX%) were extracted from the patient database using measured values obtained with the assistance of the Endo PAT, a device set to measure the signal of the peripheral arterial tone (PAT) from the blood vessels endothelium. Linear regression coefficients, Box and Whisker plots, Area under the Curve (AUC) of receiver Operation Characteristic (ROC) curves, and multiple regression were used to assess the marker accuracy using detection rate (DR) and false-positive rate (FPR) and previously reported cut-offs for estimating the positive and negative predictive value (NPV and PPV). The SPSS non-parametric statistics (Kruskal Wallis and Mann–Whitney) and Spearman’s regression coefficient were used to assess marker accuracy; p < 0.05 was considered significant. Results—MAP values reached diagnostic accuracy (AUC = 1.00, DR = 100%) for early PE cases delivered < 34, whereas UtA Doppler PI values yielded such results for early FGR < 34 weeks and the two combined reached such accuracy for PE + FGR. To reach diagnostic accuracy for all cases of the complications, the Endo PAT markers with values for MAP and UtA Doppler PI were required for cases near delivery. Multiple regression analyses showed added value for advanced maternal age and gestational week in risk assessment for all cases of PE, FGR, and PE + FGR. Spearman’s regression coefficient yielded r > 0.6 for UtA Doppler PI over GA for PE and FGR, whereas for RHI over BMI, the regression coefficient was r > 0.5 (p < 0.001 for each). Very high correlations were also found between UtA Doppler PI and sFlt-1/PlGF or PlGF (r = −0.495, p < 0.001), especially in cases of FGR. Conclusion—The classical biophysical markers MAP and UtA Doppler PI provided diagnostic accuracy for PE and FGR < 34 wks gestation. A multiple biophysical marker analysis was required to reach diagnostic accuracy for all cases of these complications. The UtA Doppler PI and maternal serum sFlt-1/PlGF or PlGF were equally accurate for early cases to enable the choice of the markers for the clinical use according to the more accessible method.

Differences and similarities in endothelial and angiogenic profiles of preeclampsia and COVID-19 in pregnancy

Background

COVID-19 presents a spectrum of signs and symptoms in pregnant women that might resemble preeclampsia. Differentiation between severe COVID-19 and preeclampsia is difficult in some cases.

Objective

To study biomarkers of endothelial damage, coagulation, innate immune response, and angiogenesis in preeclampsia and COVID-19 in pregnancy in addition to in vitro alterations in endothelial cells exposed to sera from pregnant women with preeclampsia and COVID-19.

Study Design

Plasma and sera samples were obtained from pregnant women with COVID-19 infection classified into mild (n=10) or severe (n=9) and from women with normotensive pregnancies as controls (n=10) and patients with preeclampsia (n=13). A panel of plasmatic biomarkers was assessed, including vascular cell adhesion molecule-1, soluble tumor necrosis factor-receptor I, heparan sulfate, von Willebrand factor antigen (activity and multimeric pattern), α2-antiplasmin, C5b9, neutrophil extracellular traps, placental growth factor, soluble fms-like tyrosine kinase-1, and angiopoietin 2. In addition, microvascular endothelial cells were exposed to patients’ sera, and changes in the cell expression of intercellular adhesion molecule 1 on cell membranes and von Willebrand factor release to the extracellular matrix were evaluated through immunofluorescence. Changes in inflammation cell signaling pathways were also assessed by of p38 mitogen-activated protein kinase phosphorylation. Statistical analysis included univariate and multivariate methods.

Results

Biomarker profiles of patients with mild COVID-19 were similar to those of controls. Both preeclampsia and severe COVID-19 showed significant alterations in most circulating biomarkers with distinctive profiles. Whereas severe COVID-19 exhibited higher concentrations of vascular cell adhesion molecule-1, soluble tumor necrosis factor-α receptor I, heparan sulfate, von Willebrand factor antigen, and neutrophil extracellular traps, with a significant reduction of placental growth factor compared with controls, preeclampsia presented a marked increase in vascular cell adhesion molecule-1 and soluble tumor necrosis factor-α receptor I (significantly increased compared with controls and patients with severe COVID-19), with a striking reduction in von Willebrand factor antigen, von Willebrand factor activity, and α2-antiplasmin. As expected, reduced placental growth factor, increased soluble fms-like tyrosine kinase-1 and angiopoietin 2, and a very high soluble fms-like tyrosine kinase-1 to placental growth factor ratio were also observed in preeclampsia. In addition, a significant increase in C5b9 and neutrophil extracellular traps was also detected in preeclampsia compared with controls. Principal component analysis demonstrated a clear separation between patients with preeclampsia and the other groups (first and second components explained 42.2% and 13.5% of the variance), mainly differentiated by variables related to von Willebrand factor, soluble tumor necrosis factor-receptor I, heparan sulfate, and soluble fms-like tyrosine kinase-1. Von Willebrand factor multimeric analysis revealed the absence of von Willebrand factor high-molecular-weight multimers in preeclampsia (similar profile to von Willebrand disease type 2A), whereas in healthy pregnancies and COVID-19 patients, von Willebrand factor multimeric pattern was normal.

Sera from both preeclampsia and severe COVID-19 patients induced an overexpression of intercellular adhesion molecule 1 and von Willebrand factor in endothelial cells in culture compared with controls. However, the effect of preeclampsia was less pronounced than the that of severe COVID-19. Immunoblots of lysates from endothelial cells exposed to mild and severe COVID-19 and preeclampsia sera showed an increase in p38 mitogen-activated protein kinase phosphorylation. Patients with severe COVID-19 and preeclampsia were statistically different from controls, suggesting that both severe COVID-19 and preeclampsia sera can activate inflammatory signaling pathways.

Conclusion

Although similar in in vitro endothelial dysfunction, preeclampsia and severe COVID-19 exhibit distinctive profiles of circulating biomarkers related to endothelial damage, coagulopathy, and angiogenic imbalance that could aid in the differential diagnosis of these entities.

Should angiogenic markers be included in diagnostic criteria of superimposed pre-eclampsia in women with chronic hypertension?

OBJECTIVE

Although the most recent guidance from the International Society for the Study of Hypertension in Pregnancy (ISSHP) has highlighted the role of angiogenic marker assessment in the diagnosis of pre-eclampsia (PE) in women with chronic hypertension, the ISSHP has withheld recommending its implementation due to the limited available evidence in this group of women. Therefore, we aimed to investigate the value of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) assessment in women with chronic hypertension and suspected superimposed PE.

METHODS

This was a retrospective analysis of prospectively collected data recorded in an electronic database between January 2013 and October 2019. Women with chronic hypertension and singleton pregnancy who had suspected superimposed PE were included. Superimposed PE was suspected in women presenting with worsening hypertension, epigastric pain, new-onset edema, dyspnea or neurological symptoms. The exclusion criteria were delivery within 1 week after assessment for reasons other than PE, chronic kidney disease, history of cardiac disease, fetal aneuploidy, genetic syndrome or major structural anomaly and missing pregnancy outcome. Maternal serum angiogenic markers (sFlt-1, PlGF and sFlt-1/PlGF ratio) were measured. The primary outcome was the utility of angiogenic markers in the prediction of superimposed PE. Predictive accuracy was assessed for superimposed PE diagnosed at different timepoints, including within 1 week after assessment and any time before birth. The secondary outcome was comparison of adverse maternal and perinatal outcomes between women with superimposed PE diagnosed according to the traditional ISSHP criteria and those diagnosed according to extended criteria including angiogenic markers. The predictive accuracy of each angiogenic marker was assessed using receiver-operating-characteristics-curve analysis. Area under the curve (AUC) values were compared using De Long's test. A sensitivity analysis was planned for gestational age at assessment. The association of various variables with composite adverse maternal and perinatal outcomes was assessed using binomial regression.

RESULTS

The study included 142 pregnant women with chronic hypertension and suspected superimposed PE, of whom 25 (17.6%) developed PE within 1 week after assessment, 52 (36.6%) developed PE at any timepoint before birth and 90 (63.4%) delivered without PE. Maternal serum angiogenic imbalance was associated significantly with superimposed PE diagnosed according to the ISSHP criteria within 1 week or at any time after assessment (P < 0.001 for both). The predictive accuracy of maternal serum sFlt-1/PlGF ratio for superimposed PE diagnosed within 1 week after assessment was superior to that of maternal serum PlGF level (AUC, 0.91 vs 0.86; P = 0.032). The addition of angiogenic imbalance to the traditional ISSHP diagnostic criteria was associated with an increase in the detection rate (35.1% increase; 95% credible interval (CrI), 16.6-53.6%) and positive (9.6% increase; 95% CrI, 0.0-20.6%) and negative (3.1% increase; 95% CrI, 1.3-4.9%) predictive values for composite adverse maternal outcome, with high posterior probabilities of an increase in each predictive accuracy parameter (> 99.9%, 95.6% and > 99.9%, respectively), without a meaningful decrease in specificity. The addition of angiogenic imbalance improved the detection rate for composite adverse perinatal outcome (20.6% increase; 95% CrI, 0.0-42.2%), with a high posterior probability (96.9%). There was a corresponding drop in specificity (5.7% decrease; 95% CrI, -2.3% to 13.6%), with a posterior probability of 91.8%.

CONCLUSIONS

In women with chronic hypertension and suspected superimposed PE, addition of maternal serum angiogenic markers to the traditional diagnostic criteria for superimposed PE improved significantly the sensitivity for the prediction of both maternal and perinatal adverse outcomes. Implementation of angiogenic marker assessment in the evaluation of pregnant women with chronic hypertension should therefore be considered. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Clinical interpretation and implementation of the sFlt-1/PlGF ratio in the prediction, diagnosis and management of preeclampsia

Preeclampsia is associated with significant morbidity and mortality for mother and baby. Although around 30% of all pregnancies are evaluated for preeclampsia, diagnosis is difficult, especially in patients who have overlying symptoms from other diseases. Discovery of circulating angiogenic factors in the pathogenesis of preeclampsia has been a major advance for both diagnosis and prognosis. The anti-angiogenic factor, soluble fms-like tyrosine kinase 1 (sFlt-1) and the pro-angiogenic factor, placental growth factor (PlGF), can be measured in plasma and serum and are usually reported as a ratio, which specifically relates to the onset and severity of preeclampsia. The sFlt-1/PlGF ratio has a very high negative predictive value in ruling out the development of preeclampsia within 7 days among women with suspected preeclampsia. Currently, there is no clear consensus on the practical use of angiogenic biomarkers in the detection and management of preeclampsia in routine clinical practice. While major international clinical guidelines exist, they do not define which specific parameters signal patient admission, or outpatient evaluation of suspected preeclampsia, and most clinicians follow local practices. Better guidance is needed on risk stratification among women with suspected preeclampsia, as well as among women at high risk for preeclampsia. Prediction of adverse outcomes in women, after the clinical diagnosis of preeclampsia, is also important. This report has been developed following a meeting of international experts and aims to guide clinicians in the management of pregnant women at risk of preeclampsia using the sFlt-1/PlGF ratio test.

C1431T Variant of PPARγ Is Associated with Preeclampsia in Pregnant Women

Peroxisome proliferator-activated receptor γ (PPARγ) is essential for placental development, whose SNPs have shown increased susceptibility to pregnancy-related diseases, such as preeclampsia. Our aim was to investigate the association between preeclampsia and three PPARγ SNPs (Pro12Ala, C1431T, and C681G), which together with nine clinical factors were used to build a pragmatic model for preeclampsia prediction. Data were collected from 1648 women from the EDEN cohort, of which 35 women had preeclamptic pregnancies, and the remaining 1613 women had normal pregnancies. Univariate analysis comparing preeclamptic patients to the control resulted in the SNP C1431T being the only factor significantly associated with preeclampsia (p < 0.05), with a confidence interval of 95% and odds ratio ranging from 4.90 to 8.75. On the other hand, three methods of multivariate feature selection highlighted seven features that could be potential predictors of preeclampsia: maternal C1431T and C681G variants, obesity, body mass index, number of pregnancies, primiparity, cigarette use, and education. These seven features were further used as input into eight different machine-learning algorithms to create predictive models, whose performances were evaluated based on metrics of accuracy and the area under the receiver operating characteristic curve (AUC). The boost tree-based model performed the best, with respective accuracy and AUC values of 0.971 ± 0.002 and 0.991 ± 0.001 in the training set and 0.951 and 0.701 in the testing set. A flowchart based on the boost tree model was constructed to depict the procedure for preeclampsia prediction. This final decision tree showed that the C1431T variant of PPARγ is significantly associated with susceptibility to preeclampsia. We believe that this final decision tree could be applied in the clinical prediction of preeclampsia in the very early stages of pregnancy.

Use of the angiogenic biomarker profile to risk stratify patients with fetal growth restriction

BACKGROUND

Novel angiogenic biomarker profiles have demonstrated emerging evidence for predicting preeclampsia onset, severity, and adverse outcomes. Limited data exist in screening patients with fetal growth restriction for preeclampsia development using angiogenic biomarkers.

OBJECTIVE

The objective of this study was to risk stratify patients with fetal growth restriction using a soluble fms-like tyrosine kinase-1 to placental growth factor ratio. Previously published cutoff of 38 was used to predict preeclampsia development and severity as well as adverse maternal or neonatal outcomes within a 2-week time period.

STUDY DESIGN

This was a prospective observational cohort study performed in a single tertiary hospital. Patients with a singleton fetal growth restriction pregnancy between 24 and 37 weeks' gestation were evaluated using serial 2-week encounters from the time of enrollment to delivery. Pregnancies with proven genetic or infectious etiology of fetal growth restriction or congenital anomalies were excluded. Ultrasound growth and Doppler measurements were obtained at the start of every encounter with routine preeclampsia laboratory tests and blood pressure checks when clinically indicated. Maternal serum was collected for all serial encounters and measured for soluble fms-like tyrosine kinase-1 and placental growth factor after delivery in a double-blinded fashion. Maternal charts were reviewed for baseline demographic characteristics, pregnancy diagnoses and outcomes, and neonatal outcomes.

RESULTS

A total of 45 patients were enrolled for a total of 77 encounters, with the median (quartile 1, quartile 3) gestational age of the study enrolled at 31.43 (28.14-33.57) weeks. Patients were divided into low-risk (ratio of <38) and high-risk (ratio of ≥38) groups. Baseline characteristics of patients did not show any marked differences, including preeclampsia labs or ultrasound parameters, between the 2 groups. Systolic and diastolic blood pressures upon enrollment were statistically elevated when soluble fms-like tyrosine kinase-1 to placental growth factor ratio was ≥38 (P=.02 and P=.01, respectively). Compared to patients with a low ratio, patients with a high ratio had a greater proportion of preeclampsia diagnosis, higher rates of preterm delivery under 34 and 37 weeks gestation, smaller neonatal birthweight, and a shorter time to delivery from testing to delivery.

CONCLUSION

Among patients with fetal growth restriction, the soluble fms-like tyrosine kinase-1 to placental growth factor ratio may serve as a potential biomarker for identifying at risk patients for developing preeclampsia and subsequently preterm delivery.

Maternal Serum Inhibin-A Augments the Value of Maternal Serum PlGF and of sFlt-1/PlGF Ratio in the Prediction of Preeclampsia and/or FGR Near Delivery—A Secondary Analysis

Objective: We previously provided evidence to confirm that maternal serum levels of soluble Fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), and their ratio are useful tools to direct the management of preeclampsia (PE), fetal growth restriction (FGR), and PE+FGR near delivery. In this secondary analysis, we further examine the potential additive value of maternal serum Inhibin-A, which is a hormone marker of the transforming growth factor family, to the accuracy provided by maternal serum PlGF and sFlt-1. Methods: We conducted a secondary analysis where we extracted the data of a cohort of 125 pregnant women enrolled near delivery at the clinics of the University Medical Center of Ljubljana, Slovenia. The dataset included 31 cases of PE, 16 of FGR, 42 of PE+FGR, 15 preterm delivery (PTD), and 21 unaffected controls with delivery of a healthy baby at term. Cases delivered before 34 weeks’ gestation included 10 of PE, 12 of FGR, 28 of PE+FGR, and 6 of PTD. In addition to the recorded demographic characteristics and medical history and the maternal serum levels of PlGF and sFlt-1/PlGF ratio, which were previously published, we evaluated the added value of maternal serum Inhibin-A. The predictive accuracy of each biomarker, their ratios, and combinations were estimated from areas under the curve (AUC) of receiver operating characteristics (ROC) curves, Box and Whisker plots, and by multiple regression. We estimated accuracy by the continuous marker model and a cutoff model. Results: In this study, we combined Inhibin-A with PlGF or with the sFlt-1/PlGF ratio and showed a 10–20% increase in AUCs and 15–45% increase in the detection rate, at 10% false positive rate, of PE, and a lower, but significant, increase for PE+FGR and FGR in all cases but not for FGR in early cases delivered < 34 weeks. The use of a cutoff model was adequate, although a bit higher accuracy was obtained from the continuous model. The highest correlation was found for PlGF with all three complications. Conclusion: In this secondary analysis, we have found that maternal serum Inhibin-A improves the accuracy of predicting PE and PE+FGR provided by maternal serum angiogenic markers alone, bringing the results to a diagnostic level; thus, it could be considered for directing clinical management. Inhibin-A had smaller or no added value for the accuracy of predicting FGR alone, mainly of early cases delivered <34 weeks.

Pro- and Anti-Angiogenic Markers as Clinical Tools for Suspected Preeclampsia with and without FGR near Delivery—A Secondary Analysis

Objective—the objective of this study was to assess the accuracy of placental growth factor (PlGF), soluble Fms-like Tyrosine Kinase 1 (sFlt-1), and endoglin (sEng) in the diagnosis of suspected preeclampsia (PE) with and without fetal growth restriction (FGR) near delivery. Methods—this is a secondary analysis of a dataset of 125 pregnant women presenting at the high risk pregnancy clinic with suspected PE, FGR or PE + FGR in the University Medical Center of Slovenia. The dataset included 31 PE cases, 16 FGR cases, 42 PE + FGR cases, 15 cases who developed with unrelated complications before 37 weeks (wks) (PTD), and 21 unaffected controls who delivered a healthy baby at term. We also analyzed a sub-group of women who delivered early (<34 wks) including 10 PE, 12 FGR, 28 PE + FGR, and six PTD. Clinical management adhered to hospital guidelines. Marker levels were extracted from the dataset and were used to develop Receiver Operating Characteristic (ROC) curves and to calculate the area under the curve (AUC), the detection rates (DRs), and the false positive rates (FPRs). Previously published marker cutoffs for yes/no admission to hospital wards were extracted from the literature. Negative and positive predictive values (NPVs and PPVs) were evaluated for their value in determining whether hospital admission was required. Non-parametric tests were applied for statistical analysis; p < 0.05 was considered significant. Results—near delivery, all the pro-and anti-angiogenic markers provided diagnostic (ROC = 1.00) accuracy for the early (<34 wks) group of FGR. Diagnostic or near diagnostic (ROC = 0.95) accuracy was achieved by all marker for early PE + FGR but lower accuracy was achieved for early PE. For all cases, all markers, especially PlGF reached diagnostic or near diagnostic accuracy for FGR and PE + FGR. At this accuracy level, they can contribute to the clinical management of FGR, and PE + FGR. All the markers were less accurate for all PE cases. The use of published cutoffs was adequate for clinical management of FGR, whether early or for all cases, using an NPV > 90%. For PE + FGR, the PPV value approached 100%, especially for early cases, and can thus be implemented in clinical management. Neither NPV nor PPV were high enough for managing all cases of PE. There was no added value in measuring the PlGF/(sFlt-1 + sEng) ratio. Conclusion—This is the first study on a Slovenian population. It shows that near-delivery angiogenic biomarkers tests may be useful for confirming the diseases in cases where there is a diagnostic doubt. However, the clinical use of the biomarkers needs to be weighed against resources available and degree of certainty of the diagnosis made with and without them for managing suspected FGR and PE + FGR requiring delivery <34 wks, where they are very accurate, and furthermore in the management of all cases of FGR and FGR+PE. The markers were less accurate for the clinical diagnosis of PE.