Angiogenic Marker Prognostic Models in Pregnant Women With Hypertension

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.

Immunological mechanisms in preeclampsia: A narrative review

Maternal immunologic mechanisms for tolerance are essential for a successful pregnancy because they prevent maladaptive immune responses to the placenta and semi-allogeneic fetus and promote fetal growth. Preeclampsia is a major global cause of fetal mortality and morbidity. It is characterized by new-onset hypertension and proteinuria that occurs at twenty weeks of pregnancy or later. Preeclampsia is defined by a rise in cytokines that are pro-inflammatory and antiangiogenic components in the fetoplacental unit and the vascular endothelium of pregnant women, as well as an excessive and increasing stimulation of the immune system. Crucially, inflammation can result in low birth weight and inadequate placental perfusion in neonates. Preeclampsia, which is ultimately connected to inflammatory responses, can be impacted by several immunological mechanisms. Our goal in this work was to compile the most recent research on the pathoimmunology of preeclampsia, including studies on angiogenic variables and, in particular, immunological components.

CCN1-Mediated Signaling in Placental Villous Tissues after SARS-CoV-2 Infection in Term Pregnant Women: Implications for Dysregulated Angiogenesis

The global spread of SARS-CoV-2 has increased infections among pregnant women. This study aimed to explore placental pathology alterations and angiogenic factor levels in term pregnant women after SARS-CoV-2 infection in a retrospective single-center study. Additionally, we investigated the role and underlying mechanism of the vascular inflammation-promoting, cysteine-rich protein 61 (CYR61/CCN1) in this context. All analyses were performed in term pregnant women infected with or without SARS-CoV-2. The sFlt-1, PlGF, and sEng serum levels were quantified using ELISA. Placental protein expressions were examined by immunoblot and immunostaining. Additionally, the effect of CCN1 protein on SGHPL-5 trophoblast cells was examined. We found that SARS-CoV-2 activated the inflammatory response in pregnant women, leading to pronounced vascular alterations in placental villous tissues. Elevated serum anti-angiogenic factors (sFlt-1, sEng) upon SARS-CoV-2 infection may directly contribute to these pathological changes. Upregulated CCN1 and pNF-κB in placental villous tissues of infected patients are identified as crucial factors in placental alterations. As a conclusion, CCN1 was significantly elevated in the placentas of term pregnant women infected with SARS-CoV-2. By activating a cascade of inflammatory responses, CCN1 induced the production of the anti-angiogenic factors sFlt-1 and sEng, which may lead to abnormal placental vascular architecture.

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.

Prediction of adverse outcome by ophthalmic artery Doppler and angiogenic markers in pregnancies with new onset hypertension

OBJECTIVES

To compare the ophthalmic artery Doppler peak systolic velocity ratio (OA PSV-ratio) and soluble fms-like tyrosine kinase-1/placental growth factor ratio (sFlt-1/PlGF ratio) in predicting adverse maternal and perinatal outcomes in women presenting with new onset hypertension.

STUDY DESIGN

Prospective cohort study in a specialist hypertension clinic, within a tertiary referral centre.

MAIN OUTCOME MEASURES

Comparison between the OA PSV-ratio and sFlt-1/PlGF ratio in predicting delivery within one week from presentation and adverse maternal and perinatal outcomes e.g. severe hypertension, neonatal unit admission, small for gestational age.

RESULTS

Women who delivered within one week, compared to those who did not, had a higher OA PSV-ratio (0.82 vs 0.71, p < 0.01) and sFlt-1/PlGF ratio (93.3 vs 40.5, p = 0.08). Independent predictors of the OA PSV-ratio included mean arterial pressure and maternal weight and predictors of the sFlt-1/PlGF ratio included diastolic blood pressure and use of antihypertensive medications. Prediction of adverse outcomes with both ratios were similar and only modest e.g. AUROC for predicting delivery within one week for OA PSV-ratio was 0.57 (95% CI 0.47-0.67) and for sFlt-1/PlGF ratio was 0.61 (95% CI 0.52-0.70) (p = 0.53).

CONCLUSIONS

In women presenting with new onset hypertension, the OA PSV-ratio and sFlt-1/PlGF ratio have similar and modest performance in predicting adverse outcomes.

Angiogenic biomarkers for the follow-up of singleton pregnancies with suspected preeclampsia

BACKGROUND

Preeclampsia (PE) is a hypertensive disorder of pregnancy and one of the leading causes of maternal and fetal morbidity and mortality worldwide. While the underlying cause of remains unknown, abnormal placentation in early stages of pregnancy is thought to be a main triggering event for the more severe and early-onset forms. A consequence of placental insufficiency is an imbalance of angiogenic factors in the maternal circulation. The objective was to assess the utility of the angiogenic biomarker sFlt-1/PlGF for the diagnosis, follow-up and prognosis of preeclampsia.

METHODS

This was a retrospective cohort study based including 65 consecutive singleton pregnancies with suspected preeclampsia referred to our hospital between January 2018 and February 2019. PE was defined as early-onset (20-33+6 weeks) and late-onset (≥34 weeks). The main independent variable was sFlt-1/PlGF classified in women with early or late onset PE, respectively, as low when <38 or <38, intermediate when 38-84 or 38-109, and high when ≥85 or ≥110.

RESULTS

PE was confirmed in 14 (4 early-onset, 10 late-onset) of the participants. 122 sFlt-1/PIGF ratio determinations were requested. The optimal sFlt-1/PlGF to predict PE was ≥86 with a sensitivity of 93% and a specificity of 96% (AUC 0.95; CI 95% 0.90-1.0; P<0.001). A multilevel logistic model for the diagnosis of PE was adjusted for age, Body Mass Index, diabetes, proteinuria and mean arterial pressure. Women were 16.5 times (P=0.013) more likely to develop PE if they had intermediate sFlt-1/PlGF levels and 451 times (P<0.001) more likely if they had high biomarker levels compared to those with levels below 38. The probability of PE was 3.73 times (P=0.046) greater in those with maternal and/or fetal complications.

CONCLUSIONS

The biomarker proved useful to diagnose PE and assess its prognosis. Patients diagnosed with PE had a higher frequency of complications and their newborns were of lower birth weight.

Predictive value of the sFlt‑1/PlGF ratio in women with suspected preeclampsia: An update (Review)

Preeclampsia (PE) is a major complication of pregnancy with an incidence rate of 2‑8% and is a leading cause of maternal mortality and morbidity. The various consequences of severe preeclampsia for the fetus, neonate and child include intrauterine growth retardation (IUGR), fetal hypoxia, oligohydramnios, intrauterine fetal demise, increased perinatal mortality and morbidity, neurodevelopmental disorders and even irreversible brain damage (cerebral palsy). A number of studies have demonstrated that differences in maternal serum concentrations of angiogenic factors between preeclampsia and normotensive pregnancies can be used as biomarkers, either alone or in combination with other markers, to predict the development of PE. The presence in the maternal circulation of two proteins of placental origin, placental growth factor (PlGF) and soluble fms‑like tyrosine kinase 1 (sFlt‑1), has been shown to be of clinical value, as the sFlt‑1/PlGF ratio appears to be the optimal predictive tool for the development of PE. The measurement of their concentration in maternal serum in screening models, serves as predictive marker for the development of PE or IUGR later in gestation. However, further research is required to improve its clinical applicability and provide guidelines for its use worldwide to achieve more consistent clinical management of women with PE.

sFLT1, PlGF, the sFLT1/PlGF Ratio and Their Association with Pre-Eclampsia in Twin Pregnancies-A Review of the Literature

Twin pregnancies demonstrate a 2-3-fold higher chance of developing PE compared to singletons, and recent evidence has demonstrated that the sFLT1/PIGF ratio is strongly associated with PE, adverse pregnancy outcomes, as well as imminent deliveries due to PE complications. The primary objective of this systematic review was to summarise the available data on the levels of sFLT1, PlGF and their ratios in twin pregnancies and to investigate their association with the development of PE, adverse pregnancy outcomes and the timing of the delivery. A systematic search of Ovid Embase, Web of Science, Science Direct, PubMed, Ovid Medline, Google Scholar and CINAHL was carried out. sFLT1 levels and the sFLT1/PIGF ratio appeared higher in twins compared to singleton pregnancies, especially in the third trimester, while PlGF levels appeared higher up until the third trimester, with their values showing no difference or being even lower than in singletons thereafter. The sFLT1/PIGF ratio has been reported to be an independent marker of adverse outcomes related to pre-eclampsia and is associated with the mean time until delivery in an inverse manner. Further research is required in order to establish the optimal sFLT1/PIGF cut-off values and to stratify the risk of adverse outcomes in twin pregnancies.

Preeclampsia at term can be classified into 2 clusters with different clinical characteristics and outcomes based on angiogenic biomarkers in maternal blood

BACKGROUND

An antiangiogenic state has emerged as a mechanism of disease in preeclampsia. Angiogenic biomarkers are used in the risk assessment of this syndrome, particularly of early disease. The role of an antiangiogenic state in late preeclampsia is unclear.

OBJECTIVE

This study aimed to determine the prevalence, characteristics, and clinical significance of angiogenic/antiangiogenic factor abnormalities in women with preeclampsia stratified according to gestational age at delivery.

STUDY DESIGN

Two studies were conducted: (1) a longitudinal nested case-control study comprising women with preeclampsia (n=151) and a control group (n=540); and (2) a case series of patients with preeclampsia (n=452). In patients with preeclampsia, blood was collected at the time of diagnosis. Plasma concentrations of placental growth factor and soluble fms-like tyrosine kinase-1 were determined by enzyme-linked immunosorbent assays. An abnormal angiogenic profile was defined as a plasma ratio of placental growth factor and soluble fms-like tyrosine kinase-1 expressed as a multiple of the median <10th percentile for gestational age based on values derived from the longitudinal study. The proportion of patients diagnosed with preeclampsia who had an abnormal angiogenic profile was determined in the case-series participants and stratified by gestational age at delivery into early (≤34 weeks), intermediate (34.1-36.9 weeks), and term (≥37 weeks) preeclampsia. The demographics, clinical characteristics, and pregnancy outcomes of women with preeclampsia with and without an abnormal angiogenic profile were compared.

RESULTS

The prevalence of an abnormal angiogenic profile was higher in preterm than in term preeclampsia (for early, intermediate, and term in the case-control study: 90%, 100%, and 39%; for the case series: 98%, 80%, and 55%, respectively). Women with preeclampsia at term who had an abnormal angiogenic profile were more frequently nulliparous (57% vs 35%), less likely to smoke (14% vs 26%), at greater risk for maternal (14% vs 5%) or neonatal (7% vs 1%) complications, and more often had placental lesions consistent with maternal vascular malperfusion (42% vs 23%; all, P<.05) than those without an abnormal profile. Women with preeclampsia at term who had a normal angiogenic profile had a higher frequency of chronic hypertension (36% vs 21%) and were more likely to have class ≥2 obesity (41% vs 23%) than those with an abnormal profile (both, P<.05).

CONCLUSION

Patients with early preeclampsia had an abnormal angiogenic profile in virtually all cases, whereas only 50% of women with preeclampsia at term had such abnormalities. The profile of angiogenic biomarkers can be used to classify patients with preeclampsia at term, on the basis of mechanisms of disease, into 2 clusters, which have different demographics, clinical characteristics, and risks of adverse maternal and neonatal outcomes. These findings provide a simple approach to classify preeclampsia at term and have implications for future clinical care and research.

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.

Combination of Maternal Serum ESM-1 and PLGF with Uterine Artery Doppler PI for Predicting Preeclampsia

OBJECTIVE

This study aimed to determine whether the combination of pregnancy-associated endothelial cell-specific molecule 1 (ESM-1), the placental growth factor (PLGF) in the first- and second-trimester maternal serum, and the uterine artery Doppler pulsatility index (PI) in the second trimester can predict preeclampsia (PE).

METHODS

The serum levels of ESM-1 and PLGF in 33 severe preeclampsia (SPE) patients, 18 mild preeclampsia patients (MPE), and 60 age-matched normal controls (CON) were measured. The Doppler ultrasonography was performed, and the artery pulsatility index (PI) was calculated for the same subjects.

RESULTS

The 2nd PLGF level was significantly lower and the 2nd PI was higher than those in the MPE group. Combining the 2nd PLGF with the 2nd PI yielded an AUC of 0.819 (83.33% sensitivity and 70.00% specificity). In the SPE group, the 1st ESM-1 level and the 2nd PLGF level were significantly lower, and the 2nd ESM-1 level and the 2nd PI were significantly higher in the SPE group. The combination of the 1st ESM-1, the 2nd PLGF, and the 2nd PI yielded an AUC of 0.912 (72.73% sensitivity and 95.00% specificity).

CONCLUSIONS

The 1st ESM-1 and the 2nd PLGF levels and the 2nd PI were associated with PE. The combination of serum biomarkers and the PI improved the screening efficiency of the PE prediction, especially for SPE.

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

Objective

To compare the prognostic performance of biomarkers soluble fms-like tyrosine kinase-1 (sFlt-1), Placental Growth Factor (PIGF), and sFlt-1/PIGF ratio as continuous values or as a binary cut-off of 38 for predicting preeclampsia (PE) within 7 days.

Design

Secondary analysis of a randomised clinical trial.

Setting

Oxford University Hospitals, Oxford, United Kingdom (UK).

Population

Pregnant women between 24⁺⁰ to 37⁺⁰ weeks of gestation with a clinical suspicion of preeclampsia.

Main outcome

Onset of preeclampsia within 7 days of the initial biomarker test.

Methods

Logistic regression model for onset of preeclampsia using: (i) sFlt-1 (ii) PIGF, (iii) sFlt-1/PIGF ratio (continuous), and (iv) sFlt-1/PIGF ratio as a cut-off above or below 38.

Results

Of the total 370 women, 42 (11.3%) developed PE within 7 days of screening. Models with sFlt-1 and sFlt-1/PIGF ratio (continuous) had greater overall performance than models with PIGF or with sFlt-1/PIGF ratio as a cut-off at 38 (R²: sFlt-1 = 55%, PIGF = 38%, sFlt-1/PIGF ratio = 57%, sFlt-1/PIGF ratio as cut-off at 38 model = 46%). The discrimination performance was the highest in sFlt-1 and sFlt-1/PIGF ratio (continuous) (c-statistic, sFlt-1 = 0.94, sFlt-1/PIGF ratio (continuous) = 0.94) models compared to PIGF or sFlt-1/PIGF cut-off models (c-statistic, PIGF = 0.87, sFlt-1/PIGF cut-off = 0.89).

Conclusion

Models using continuous values of sFlt-1 only or sFlt-1/PIGF ratio had better predictive performance compared to a PIGF only or the model with sFlt-1/PIGF ratio as a cut-off at 38. Further studies based on a larger sample size are warranted to substantiate this finding.

Real-world data on the clinical use of angiogenic factors in pregnancies with placental dysfunction

BACKGROUND

In routine clinical practice, angiogenic factor measurement can facilitate prediction and diagnosis of preeclampsia and other manifestations of placental dysfunction (eg, intrauterine growth restriction).

OBJECTIVE

This real-world data analysis investigated the utility of soluble fms-like tyrosine kinase-1 and placental growth factor for preeclampsia and placental dysfunction.

STUDY DESIGN

Blood serum soluble fms-like tyrosine kinase-1 and placental growth factor were measured using Elecsys soluble fms-like tyrosine kinase-1 and placental growth factor immunoassays (cobas e analyzer; Roche Diagnostics). Overall, 283 unselected singleton pregnancies with ≥1 determination of soluble fms-like tyrosine kinase-1-to-placental growth factor ratio were included. Distribution of the ratio at admission was normal (<38 [58.7%]), intermediate (38-85/110 [19.1%]), or pathologic (>85/110 [22.3%]). Overall, 15.5% had preeclampsia or hemolysis, elevated liver enzyme levels, and low platelet count, and 15.5% of women had intrauterine growth restriction.

RESULTS

Increasing soluble fms-like tyrosine kinase-1-to-placental growth factor ratio was associated with an increase in priority of delivery (r=0.38; P<.001). The percentage of patients who developed preeclampsia by soluble fms-like tyrosine kinase-1-to-placental growth factor ratio at admission was 5.4% (normal), 7.4% (intermediate), and 49.2% (pathologic). The greatest difference in soluble fms-like tyrosine kinase-1-to-placental growth factor ratio from admission to birth occurred in pathologic pregnancies (171.12 vs 39.84 for normal pregnancies). Soluble fms-like tyrosine kinase-1-to-placental growth factor ratio correlated inversely with gestational age at delivery, birthweight, and prolongation time. There was no significant relation between the prolongation period or the gestational age at first determination to the increase of soluble fms-like tyrosine kinase-1 and placental growth factor between admission and delivery (ΔQ). This analysis used a real-world approach to investigate the clinical utility of the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio in placental dysfunction.

CONCLUSIONS

Confirming the results of prospective studies, we observed a positive correlation between soluble fms-like tyrosine kinase-1-to-placental growth factor ratio and severity of placental dysfunction and a negative association with time to delivery. In a real-world setting, the soluble fms-like tyrosine kinase-1-placental growth factor ratio stratifies patients with normal outcome and outcome complicated by placental dysfunction.

The placenta and preeclampsia: villain or victim?

Preeclampsia is a disease whose characterization has not changed in the 150 years since the cluster of signs associated with the disorder were first described. Although our understanding of the pathophysiology of preeclampsia has advanced considerably since then, there is still little consensus regarding the true etiology of preeclampsia. As a consequence, preeclampsia has earned the moniker "disease of theories," predominantly because the underlying biological mechanisms linking clinical epidemiologic findings to observed organ dysfunction in preeclampsia are far from clear. Despite the lack of cohesive evidence, expert consensus favors the hypothesis that preeclampsia is a primary placental disorder. However, there is now emerging evidence that suboptimal maternal cardiovascular performance resulting in uteroplacental hypoperfusion is more likely to be the cause of secondary placental dysfunction in preeclampsia. Preeclampsia and cardiovascular disease share the same risk factors, preexisting cardiovascular disease is the strongest risk factor (chronic hypertension, congenital heart disease) for developing preeclampsia, and there are now abundant data from maternal echocardiography and angiogenic marker studies that cardiovascular dysfunction precedes the development of preeclampsia by several weeks or months. Importantly, cardiovascular signs and symptoms (hypertension, cerebral edema, cardiac dysfunction) predominate in preeclampsia at clinical presentation and persist into the postnatal period with a 30% risk of chronic hypertension in the decade after birth. Placental malperfusion caused by suboptimal maternal cardiovascular performance may lead to preeclampsia, thereby explaining the preponderance of cardiovascular drugs (aspirin, calcium, statins, metformin, and antihypertensives) in preeclampsia prevention strategies. Despite the seriousness of the maternal and fetal consequences, we are still developing sensitive screening, reliable diagnostic, effective therapeutic, or improvement strategies for postpartum maternal cardiovascular legacy in preeclampsia. The latter will only become clear with an acceptance and understanding of the cardiovascular etiology of preeclampsia.

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.

Toward personalized management of chronic hypertension in pregnancy

Chronic hypertension complicates 1% to 2% of pregnancies, and it is increasingly common. Women with chronic hypertension are an easily recognized group who are in touch with a wide variety of healthcare providers before, during, and after pregnancy, mandating that chronic hypertension in pregnancy be within the scope of many practitioners. We reviewed recent data on management to inform current care and future research. This study is a narrative review of published literature. Compared with normotensive women, women with chronic hypertension are at an increased risk of maternal and perinatal complications. Women with chronic hypertension who wish to be involved in their care can do by measuring blood pressure at home. Accurate devices for home blood pressure monitoring are now readily available. The diagnostic criteria for superimposed preeclampsia remain problematic because most guidelines continue to include deteriorating blood pressure control in the definition. It has not been established how angiogenic markers may aid in confirmation of the diagnosis of superimposed preeclampsia when suspected, over and above information provided by routinely available clinical data and laboratory results. Although chronic hypertension is a strong risk factor for preeclampsia, and aspirin decreases preeclampsia risk, the effectiveness specifically among women with chronic hypertension has been questioned. It is unclear whether calcium has an independent effect in preeclampsia prevention in such women. Treating hypertension with antihypertensive therapy halves the risk of progression to severe hypertension, thrombocytopenia, and elevated liver enzymes, but a reduction in preeclampsia or serious maternal complications has not been observed; however, the lack of evidence for the latter is possibly owing to few events. In addition, treating chronic hypertension neither reduces nor increases fetal or newborn death or morbidity, regardless of the gestational age at which the antihypertensive treatment is started. Antihypertensive agents are not teratogenic, but there may be an increase in malformations associated with chronic hypertension itself. At present, blood pressure treatment targets used in clinics are the same as those used at home, although blood pressure values tend to be inconsistently lower at home among women with hypertension. Although starting all women on the same antihypertensive medication is usually effective in reducing blood pressure, it remains unclear whether there is an optimal agent for such an approach or how best to use combinations of antihypertensive medications. An alternative approach is to individualize care, using maternal characteristics and blood pressure features beyond blood pressure level (eg, variability) that are of prognostic value. Outcomes may be improved by timed birth between 38 0/7 and 39 6/7 weeks' gestation based on observational literature; of note, confirmatory trial evidence is pending. Postnatal care is facilitated by the acceptability of most antihypertensives (including angiotensin-converting enzymes inhibitors) for use in breastfeeding. The evidence base to guide the care of pregnant women with chronic hypertension is growing and aligning with international guidelines. Addressing outstanding research questions would inform personalized care of chronic hypertension in pregnancy.

Imbalances in circulating angiogenic factors in the pathophysiology of preeclampsia and related disorders

Preeclampsia is a devastating medical complication of pregnancy that can lead to significant maternal and fetal morbidity and mortality. It is currently believed that there is abnormal placentation in as early as the first trimester in women destined to develop preeclampsia. Although the etiology of the abnormal placentation is being debated, numerous epidemiologic and experimental studies suggest that imbalances in circulating angiogenic factors released from the placenta are responsible for the maternal signs and symptoms of preeclampsia. In particular, circulating levels of soluble fms-like tyrosine kinase 1, an antiangiogenic factor, are markedly increased in women with preeclampsia, whereas free levels of its ligand, placental, growth factor are markedly diminished. Alterations in these angiogenic factors precede the onset of clinical signs of preeclampsia and correlate with disease severity. Recently, the availability of automated assays for the measurement of angiogenic biomarkers in the plasma, serum, and urine has helped investigators worldwide to demonstrate a key role for these factors in the clinical diagnosis and prediction of preeclampsia. Numerous studies have reported that circulating angiogenic biomarkers have a very high negative predictive value to rule out clinical disease among women with suspected preeclampsia. These blood-based biomarkers have provided a valuable tool to clinicians to accelerate the time to clinical diagnosis and minimize maternal adverse outcomes in women with preeclampsia. Angiogenic biomarkers have also been useful to elucidate the pathogenesis of related disorders of abnormal placentation such as intrauterine growth restriction, intrauterine fetal death, twin-to-twin transfusion syndrome, and fetal hydrops. In summary, the discovery and characterization of angiogenic proteins of placental origin have provided clinicians a noninvasive blood-based tool to monitor placental function and health and for early detection of disorders of placentation. Uncovering the mechanisms of altered angiogenic factors in preeclampsia and related disorders of placentation may provide insights into novel preventive and therapeutic options.

A machine-learning-based algorithm improves prediction of preeclampsia-associated adverse outcomes

BACKGROUND

Preeclampsia presents a highly prevalent burden on pregnant women with an estimated incidence of 2% to 5%. Preeclampsia increases the maternal risk of death 20-fold and is one of the main causes of perinatal morbidity and mortality. Novel biomarkers, such as soluble fms-like tyrosine kinase-1 and placental growth factor in addition to a wide span of conventional clinical data (medical history, physical symptoms, laboratory parameters, etc.), present an excellent basis for the application of early-detection machine-learning models.

OBJECTIVE

This study aimed to develop, train, and test an automated machine-learning model for the prediction of adverse outcomes in patients with suspected preeclampsia.

STUDY DESIGN

Our real-world dataset of 1647 (2472 samples) women was retrospectively recruited from women who presented to the Department of Obstetrics at the Charité - Universitätsmedizin Berlin, Berlin, Germany, between July 2010 and March 2019. After standardization and data cleaning, we calculated additional features regarding the biomarkers soluble fms-like tyrosine kinase-1 and placental growth factor and sonography data (umbilical artery pulsatility index, middle cerebral artery pulsatility index, mean uterine artery pulsatility index), resulting in a total of 114 features. The target metric was the occurrence of adverse outcomes throughout the remaining pregnancy and 2 weeks after delivery. We trained 2 different models, a gradient-boosted tree and a random forest classifier. Hyperparameter training was performed using a grid search approach. All results were evaluated via a 10 × 10-fold cross-validation regimen.

RESULTS

We obtained metrics for the 2 naive machine-learning models. A gradient-boosted tree model was performed with a positive predictive value of 88%±6%, a negative predictive value of 89%±3%, a sensitivity of 66%±5%, a specificity of 97%±2%, an overall accuracy of 89%±3%, an area under the receiver operating characteristic curve of 0.82±0.03, an F1 score of 0.76±0.04, and a threat score of 0.61±0.05. The random forest classifier returned an equal positive predictive value (88%±6%) and specificity (97%±1%) while performing slightly inferior on the other available metrics. Applying differential cutoffs instead of a naive cutoff for positive prediction at ≥0.5 for the classifier's results yielded additional increases in performance.

CONCLUSION

Machine-learning techniques were a valid approach to improve the prediction of adverse outcomes in pregnant women at high risk of preeclampsia vs current clinical standard techniques. Furthermore, we presented an automated system that did not rely on manual tuning or adjustments.

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

The definition of preeclampsia is changing. However, with the addition of organ symptoms to the presence of hypertension in pregnancy instead of relying only on proteinuria, a more precise detection of women at risk of preeclampsia-associated adverse events has not been achieved. Instead, under the new definitions of the American College of Obstetricians and Gynecologists and of the International Society for the Study of Hypertension in Pregnancy, more women are classified as preeclamptic, with a tendency to milder disease. Furthermore, angiogenic and antiangiogenic factors have emerged as essential tools for predicting and diagnosing preeclampsia at high accuracies. Next to being rooted in the pathophysiology of the disease, they have been proven to be reliable tools for predicting and diagnosing the disease. In addition, 2 cutoffs have been evaluated for the clinical setting. As shown in the Prediction of Short-Term Outcome in Pregnant Women With Suspected Preeclampsia Study, at the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio cutoff of 38, a preeclampsia can be ruled out for 1 week with a negative predictive value of 99.3% (95% confidence interval, 97.9-99.9) and ruled in with a positive predictive value of 36.7% (95% confidence interval, 28.4-45.7). The diagnostic cutoff of 85 has been shown to accurately identify women with preeclampsia, with a sensitivity of up to 88% and a specificity of 99.5%. In this review, we highlight the central role of angiogenic and antiangiogenic factors in the differential diagnosis of women presenting at high risk of the disease, such as patients with chronic hypertension or chronic kidney disease. We will focus on their ability to predict preeclampsia-associated adverse fetal and maternal outcomes. This is only possible when critically reviewing the evolution of the definition of "preeclampsia." We show how changes in this definition shape our clinical picture of the condition and how angiogenic and antiangiogenic biomarkers might be included to better identify women destined to develop preeclampsia-related adverse outcomes.

Impact of Chronic Kidney Disease on the Associations of Cardiovascular Biomarkers With Adverse Outcomes in Patients With Suspected or Known Coronary Artery Disease: The EXCEED-J Study

Background

The impact of chronic kidney disease (CKD) on the prognostic utility of cardiovascular biomarkers in high‐risk patients remains unclear.

Methods and Results

We performed a multicenter, prospective cohort study of 3255 patients with suspected or known coronary artery disease (CAD) to investigate whether CKD modifies the prognostic utility of cardiovascular biomarkers. Serum levels of cardiovascular and renal biomarkers, including soluble fms‐like tyrosine kinase‐1 (sFlt‐1), N‐terminal pro‐brain natriuretic peptide (NT‐proBNP), high‐sensitivity cardiac troponin‐I (hs‐cTnI), cystatin C, and placental growth factor, were measured in 1301 CKD and 1954 patients without CKD. The urine albumin to creatinine ratio (UACR) was measured in patients with CKD. The primary outcome was 3‐point MACE (3P‐MACE) defined as a composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke. The secondary outcomes were all‐cause death, cardiovascular death, and 5P‐MACE defined as a composite of 3P‐MACE, heart failure hospitalization, and coronary/peripheral artery revascularization. After adjustment for clinical confounders, sFlt‐1, NT‐proBNP, and hs‐cTnI, but not other biomarkers, were significantly associated with 3P‐MACE, all‐cause death, and cardiovascular death in the entire cohort and in patients without CKD. These associations were still significant in CKD only for NT‐proBNP and hs‐cTnI. NT‐proBNP and hs‐cTnI were also significantly associated with 5P‐MACE in CKD. The UACR was not significantly associated with any outcomes in CKD. NT‐proBNP and hs‐cTnI added incremental prognostic information for all outcomes to the model with potential clinical confounders in CKD.

Conclusions

NT‐proBNP and hs‐cTnI were the most powerful prognostic biomarkers in patients with suspected or known CAD and concomitant CKD.

The Novel Peptide AEDPPE Alleviates Trophoblast Cell Dysfunction Associated With Preeclampsia by Regulating the NF-κB Signaling Pathway

Background: Preeclampsia (PE) is a serious risk to the health of pregnant women and fetuses during pregnancy, and there is no effective treatment for this condition. Although many reports have confirmed the therapeutic effects of peptides in diseases, the role of peptides in PE remains poorly understood.

Methods: A differentially expressed peptide in PE (AEDPPE) is derived from heat-shock protein beta-1 (HSPB1), amino acids 100 to 109 (DVNHFAPDEL), which we identified in a previous study. We synthesized AEDPPE and investigated its effect on HTR-8/SVneo cell function using a Cell Counting Kit-8, flow cytometric assay, and Transwell and wound-healing assays. Quantitative reverse transcription-PCR and ELISA were used to determine cytokine expression. Pull-down assay, mass spectrometry, Western blot analysis, and immunofluorescence were used to explore the potential targets and signaling pathways regulated by AEDPPE. Finally, we assessed the effect of AEDPPE in the lipopolysaccharide (LPS)-induced PE-like rat model.

Results: AEDPPE significantly promoted the migration and invasion of HTR-8/SVneo cells, and it decreased the expression of interleukins 1 beta (IL-1β), interleukin 6 (IL-6), and interleukin 8 (IL-8). These functions performed by AEDPPE remained evident after injury to HTR-8/SVneo cells with tumor necrosis factor-alpha (TNF-α), and AEDPPE reversed the elevated sFlt-1/PlGF ratio induced by TNF-α. AEDPPE may exert these biological effects by binding to heat-shock protein 90β (HSP 90β) and, thus, affect the NF-κB signaling pathway. In an LPS-induced PE-like rat model, AEDPPE significantly improved PE symptoms and fetal rat outcomes.

Conclusion: Our study showed that AEDPPE enhanced trophoblast migration and invasion and reduced inflammatory cytokine expression, and we hypothesized that these actions involved the NF-κB signaling pathway. The use of AEDPPE may thus develop into a novel modality in the treatment of PE.

Relationship between the sFlt-1/PlGF ratio and the optical coherence tomographic features of chorioretina in patients with preeclampsia

This study aimed to evaluate the correlation between ophthalmologic factors and the serologic indicator soluble fms-like tyrosine kinase 1 (sFlt-1): placental growth factor (PlGF) ratio in patients with preeclampsia using optical coherence tomography (OCT) and OCT angiography (OCT-A). A total of 52 pregnant patients (104 eyes) diagnosed with preeclampsia were recruited during their hospital stay. The associations between the sFlt-1/PlGF ratio and chorioretinal measurements, including the choroidal thickness (CT), foveal avascular zone, vascular density, and ganglion cell layer+ were evaluated. Central and nasal subfield CT of the left eye (p = 0.039; p = 0.010) and nasal subfield CT of the right eye (p = 0.042) were lower in the high sFlt-1/PlGF ratio group (≥38). Pearson’s correlation test showed a negative correlation between the sFlt-1/PlGF ratio and central subfield CT; however, this was not statistically significant (p = 0.648). Linear regression analysis revealed a significant association between the sFlt-1/PlGF ratio and central subfield CT (β coefficient, -6.66; p = 0.01) and between sFlt-1 and central subfield CT (β coefficient, -5.65; p = 0.00). Thus, an increase in the sFlt-1/PlGF ratio resulted in a decrease in central subfield CT.

Prognostic Value of Angiogenic Markers in Pregnant Women With Chronic Hypertension

Background

Women with chronic hypertension face a 5‐ to 6‐fold increased risk of developing preeclampsia compared with normotensive women. Angiogenic markers, especially soluble fms‐like kinase 1 (sFlt‐1) and placental growth factor (PlGF), were identified as clinically useful markers predicting the development of preeclampsia, but data on the prediction of superimposed preeclampsia are scarce. Therefore, we aimed to evaluate the predictive value of the sFlt‐1/PlGF ratio for delivery because of superimposed preeclampsia in women with chronic hypertension.

Methods and Results

This retrospective study included 142 women with chronic hypertension and suspected superimposed preeclampsia. Twenty‐seven women (19.0%) delivered because of maternal indications only, 17 women (12.0%) because of fetal indications primarily, and 98 women (69.0%) for other reasons. Women who both delivered because of maternal indications and for fetal indications had a significantly higher sFlt‐1/PlGF ratio (median 99.9 and 120.2 versus 7.3, respectively, P<0.001 for both) and lower PlGF levels (median 73.6 and 53.3 versus 320.0 pg/mL, respectively, P<0.001 for both) compared with women who delivered for other reasons. SFlt‐1/PlGF ratio and PlGF were strong predictors for delivery because of superimposed preeclampsia, whether for maternal or fetal indications (P<0.05). Half of women with angiogenic imbalance (sFlt‐1/PlGF ratio ≥85 or PlGF levels <100 pg/mL) delivered because of maternal or fetal indications within 1.6 weeks (95% CI, 1.0–2.4 weeks).

Conclusions

Angiogenic marker imbalance in women with suspected superimposed preeclampsia can predict delivery because of maternal and fetal indications related to superimposed preeclampsia and is associated with a significantly shorter time to delivery interval.

Angiogenic markers and their longitudinal change for predicting adverse outcomes in pregnant women with chronic hypertension

BACKGROUND

Women with chronic hypertension are at increased risk for adverse maternal and perinatal outcomes. Maternal serum angiogenic markers, such as soluble fms-like tyrosine kinase 1 and placental growth factor, can be used to triage women with suspected preeclampsia. However, data about these markers in pregnant women with chronic hypertension are scarce.

OBJECTIVE

We aimed to evaluate the predictive accuracy of maternal serum levels of soluble fms-like tyrosine kinase 1, placental growth factor, and their ratio for predicting adverse maternal and perinatal outcomes in women with chronic hypertension.

STUDY DESIGN

This was a retrospective analysis of prospectively collected data from January 2013 to October 2019 at the University of Vienna Hospital, Vienna, Austria. The inclusion criteria were pregnant women with chronic hypertension and suspected preeclampsia. The primary outcome of this study was the prognostic performance of angiogenic markers for the prediction of adverse maternal and perinatal outcomes in pregnant women with chronic hypertension. The accuracy of angiogenic markers for predicting adverse composite outcomes was assessed with a binomial logistic regression. The accuracy of each marker was assessed using receiver operating characteristics curves and area under the curve values. Area under the curve values were compared using De Long's test.

RESULTS

Of the 145 included women with chronic hypertension and suspected superimposed preeclampsia, 26 (17.9%) women developed complications (ie, composite adverse maternal or fetal outcomes) within 1 week of assessment (average gestational age at assessment, 29.9 weeks) and 35 (24.1%) developed complications at any time (average gestational age at assessment, 30.1 weeks). In women who developed complications at any time, the median maternal serum soluble fms-like tyrosine kinase-1 to placental growth factor ratio was 149.4 (interquartile range, 64.6-457.4) compared with 8.0 (interquartile range, 3.37-41.2) for women who did not develop complications (P<.001). The area under the curve values for the maternal serum soluble fms-like tyrosine kinase-1 to placental growth factor ratio Z-score (0.95; 95% confidence interval, 0.90-0.99) and placental growth factor level Z-score (0.94; 95% confidence interval, 0.88-0.99) for predicting complications within 1 week of assessment were very high. The area under the curve values for new-onset edema (0.61; 95% confidence interval, 0.52-0.70), proteinuria (0.62; 95% confidence interval, 0.52-0.71), high mean arterial pressure (0.52; 95% confidence interval, 0.50-0.54), and other symptoms of preeclampsia (0.57; 95% confidence interval, 0.49-0.65) were all significantly lower than for the angiogenic markers (P<.001 for all). Women who had an angiogenic imbalance and/or proteinuria had the highest rate of complications (28/57, 49.1%). The rate of complications in women with an angiogenic imbalance and/or proteinuria was significantly higher than in women with either proteinuria, other symptoms, or intrauterine growth restriction in the absence of an angiogenic imbalance (49.1% vs 16.7%; P=.039). The highest positive and negative predictive values for predicting adverse outcomes were demonstrated by an angiogenic imbalance and/or proteinuria criteria with a positive predictive value of 49.1% (95% confidence interval, 50.4%-57.9%) and a negative predictive value of 92% (95% confidence interval, 85.5%-95.8%). Longitudinal changes in measurements of the gestational age-corrected ratio of soluble fms-like tyrosine kinase-1 to placental growth factor up to the last measurement had a significantly higher area under the curve value than the last measurement alone (area under the curve, 0.95; 95% confidence interval, 0.92-0.99 vs 0.87; 95% confidence interval, 0.79-0.95; P=.024) CONCLUSION: Maternal serum angiogenic markers are superior to clinical assessment in predicting adverse maternal and perinatal outcomes in pregnant women with chronic hypertension. Repeated measurements of the ratio of soluble fms-like tyrosine kinase-1 to placental growth factor seems beneficial given the better predictive accuracy compared with a single measurement alone. The use of angiogenic makers should be implemented in clinical management guidelines for pregnant women with chronic hypertension.

Prediction of Adverse Pregnancy Outcome Related to Placental Dysfunction Using the sFlt-1/PlGF Ratio: A Narrative Review

The sFlt-1 (soluble fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio is a helpful tool for the prediction and diagnosis of preeclampsia (PE). Current data even show that the ratio has the potential to predict adverse pregnancy outcomes (APO) caused by placental pathologies. The aim of this article is to give a brief overview of recent findings on APO predictions based on the sFlt-1/PlGF ratio. The focus is on obstetric pathologies related to placental dysfunction (PD) such as PE and/or fetal growth restriction (FGR). New uses of the sFlt-1/PlGF ratio as a predictor of APO demonstrate its potential with regard to planning hospitalization and corticosteroid administration and the optimal timing of delivery. However, prospective interventional studies are warranted to define the exact role of the sFlt-1/PlGF ratio as a predictor of adverse pregnancy outcomes caused by placental pathologies.

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.

Prediction of Preeclampsia-Related Adverse Outcomes With the sFlt-1 (Soluble fms-Like Tyrosine Kinase 1)/PlGF (Placental Growth Factor)-Ratio in the Clinical Routine: A Real-World Study

This retrospective real-world study investigated the clinical use of the sFlt-1 (soluble fms-like tyrosine kinase 1)/PlGF (placental growth factor) ratio alone or in combination with other clinical tests to predict an adverse maternal (maternal death, kidney failure, hemolysis elevated liver enzymes low platelets-syndrome, pulmonary edema, disseminated intravascular coagulation, cerebral hemorrhage, or eclampsia) or fetal (delivery before 34 weeks because of preeclampsia and/or intrauterine growth restriction, respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage, placental abruption or intrauterine fetal death or neonatal death within 7 days post natum) pregnancy outcome in patients with signs and symptoms of preeclampsia. We evaluated the sFlt-1/PlGF-ratio cutoff values of 38 and 85 and evaluated its integration into a multimarker model. Of 1117 subjects, 322 (28.8%) developed an adverse fetal or maternal outcome. Patients with an adverse versus no adverse outcome had a median sFlt-1/PlGF-ratio of 177 (interquartile range, 54-362) versus 14 (4-64). Risk-stratification with the sFlt-1/PlGF cutoff values into high- (>85), intermediate- (38-85), and low-risk (<38) showed a significantly shorter time to delivery in high- and intermediate- versus low-risk patients (4 versus 8 versus 29 days). When integrating all available clinical information into a multimarker model, an area under the curve of 88.7% corresponding to a sensitivity, specificity, positive and negative predictive value of 80.0%, 87.3%, 75.0%, and 90.2% was reached. The sFlt-1/PlGF-ratio alone was inferior to the full model with an area under the curve of 85.7%. As expected, blood pressure and proteinuria were significantly less accurate with an area under the curve of 69.0%. Combining biomarker measurements with all available information in a multimarker modeling approach increased detection of adverse outcomes in women with suspected disease.

Affinity-Enhanced Multimeric VEGF (Vascular Endothelial Growth Factor) and PlGF (Placental Growth Factor) Variants for Specific Adsorption of sFlt-1 to Restore Angiogenic Balance in Preeclampsia

Preeclampsia is a potentially life-threatening multisystem disease affecting 4% to 8% of pregnant women after the 20th week of gestation. An excess of placental expressed antiangiogenic soluble VEGF (vascular endothelial growth factor)-receptor 1 (soluble FMS-like tyrosine kinase 1) scavenges VEGF and PlGF (placental growth factor), causing generalized endothelial dysfunction. Interventions to restore the angiogenic balance in preeclamptic pregnancies are intensively studied and improve maternal and neonatal outcomes. Especially extracorporeal strategies to remove sFlt-1 are promising in human pregnancy. However, available apheresis systems adsorb sFlt-1 unspecifically and with low efficiency. Affinity-enhanced ligands are needed to improve performance and compatibility of apheresis treatments. Using computerized molecular modeling, we developed multimeric VEGF molecules comprised of single-chain VEGF¹⁶⁵ dimers (scVEGF¹⁶⁵). A short peptide linker hampers intrachain dimerization to induce assembly preferably as tetrameric molecules as visualized in negative staining electron microscopy. scVEGF¹⁶⁵ multimers possess 1.2-fold higher affinity for sFlt-1 as compared to the available antibodies or monomeric VEGF. Consequently, scVEGF multimers have the ability to competitively release sFlt-1 bound PlGF and, in particular, VEGF. In ex vivo adsorption experiments using serum samples from patients with preeclampsia, scVEGF multimers reduce sFlt-1 levels by 85% and increase PlGF and VEGF levels by 20- and 9-fold, respectively. Finally, performance and stability of sFlt-1 capturing scVEGF¹⁶⁵ multimers were scrutinized on different matrices of which biocompatible agarose matrix yielded optimal results. We introduce the first VEGF-based highly efficient sFlt-1 apheresis system that is directly applicable in vivo due to utilization of inert agarose matrix, using a homomultimeric form of VEGF¹⁶⁵ to restore the angiogenic balance in preeclampsia.

Prognostic Value of Maternal Cardiovascular Hemodynamics in Women With Gestational Hypertension and Chronic Hypertension in Pregnancy

This study aimed to assess the prognostic value of cardiovascular assessment in women with gestational hypertension or chronic hypertension for the risk of preeclampsia and need for closer antenatal surveillance. This was a prospective study of pregnancies complicated by gestational hypertension or chronic hypertension presenting to St George's Hospital, between January 2015 and May 2018. A noninvasive ultrasonic cardiac output monitor was used to obtain cardiovascular variables of cardiac output (CO) and systemic vascular resistance (SVR) and weight-adjusted indices. The primary outcome was the time to development of preeclampsia in women with gestational hypertension or chronic hypertension. In women with gestational hypertension or chronic hypertension (n=149), cox-proportional hazards analysis showed that mean arterial pressure (P=0.006), Afro-Caribbean ethnicity (P=0.045), and gestational age at the time of diagnosis above 34 weeks (P<0.001) were significantly associated with increased risk of earlier preeclampsia. Women with high SVR and normal CO (adjusted hazard ratio, 2.32 [95% CI, 1.06-5.08]; P=0.035) and high SVR and low CO (adjusted hazard ratio, 7.79 [95% CI, 1.94-31.24]; P=0.003) cardiovascular profiles had significantly higher risk of earlier preeclampsia compared with women with normal SVR and normal CO. The findings of this study demonstrate that hypertensive women with increased SVR and low CO had a higher risk of developing preeclampsia sooner.

The Prognostic Value of Angiogenic Markers in Twin Pregnancies to Predict Delivery Due to Maternal Complications of Preeclampsia

The sFlt-1 (soluble fms-like tyrosine kinase-1), PlGF (placental growth factor), and their ratio are useful for predicting delivery because of preeclampsia in singleton pregnancies. Evidence on the utility of sFlt-1/PlGF ratio in twin pregnancies is lacking. We aimed to evaluate the predictive value of sFlt-1/PlGF ratio for delivery because of preeclampsia in twins. A retrospective data analysis of 164 twin pregnancies with suspected preeclampsia was performed. The sFlt-1/PlGF ratio, which was known to clinicians, was significantly higher in women who delivered within 1 and 2 weeks compared with those who did not (median: 98.9 and 84.2 versus 23.5 pg/mL, respectively; P<0.001). The area under the curve values sFlt-1/PlGF ratio levels were 0.88 (95% CI, 0.83-0.84) and 0.88 (95% CI, 0.83-0.93) for predicting delivery because of preeclampsia within 1 and 2 weeks of blood sampling, respectively. The predictive accuracy of sFlt-1/PlGF was independent of gestational age at sampling and chorionicity (P>0.100 for interaction). The area under the curve values of sFlt-1/PlGF were significantly higher than for PlGF alone (mean 0.88 and 0.88 versus 0.81 and 0.80) for predicting delivery because of preeclampsia within 1 and 2 weeks of blood sampling (P=0.055 and 0.001, respectively). sFlt-1/PlGF ratio lower than 38 was able to rule-out delivery within 1 and 2 weeks with a negative predictive value of 98.8% and 96.4% for delivery because of preeclampsia within 1 and 2 weeks, respectively. A cutoff of 38 is applicable for ruling out delivery because of preeclampsia in twin pregnancies.

Placental Growth Factor and Soluble, Fms-Like Tyrosine Kinase-1 in Preeclampsia: A Case-Cohort (PEARL) Study

OBJECTIVE

Preeclampsia is associated with a higher maternal blood levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and lower levels of placental growth factor (PlGF) that appear before clinical onset. We aimed to estimate the normal progression of these biomarkers in normal pregnancies and in those affected by preeclampsia.

METHODS

We conducted a case-cohort study including low-risk nulliparous women recruited at 11-13 weeks gestation (cohort) and women with preeclampsia (cases). Maternal blood was collected at different points during pregnancy including at the time of diagnosis of preeclampsia for cases. Maternal serum PlGF and sFlt-1 concentrations and the sFlt-1/PlGF ratio were measured using B•R•A•H•M•S plus KRYPTOR automated assays and were compared between patients in both groups matched for gestational age. Cases were stratified as early- (≤34 weeks), intermediate- (35-37 weeks) and late-onset (>37 weeks) preeclampsia.

RESULTS

The cohort consisted of 45 women whose results were compared with those of 31 women who developed preeclampsia, diagnosed at a median gestational age of 32 weeks (range 25-38 weeks). We observed that sFlt-1, PlGF and their ratio fluctuated during pregnancy in both groups, with a significant correlation with gestational age after 28 weeks (P < 0.05). We observed a significant difference between cases and controls, with a median ratio 100 times higher in early preeclampsia (P < 0.001), 13 times higher in intermediate preeclampsia (P < 0.001), but no significant difference between groups in late-onset preeclampsia with matched controls.

CONCLUSION

PlGF, sFlt-1, and their ratio may be useful in the prediction and diagnosis of early- and intermediate-onset preeclampsia but are not useful for late-onset preeclampsia.

Increased Angiogenesis and Lymphangiogenesis in the Placental Villi of Women with Chronic Venous Disease during Pregnancy

Pregnancy is a period in a woman’s life associated with an increased risk of developing lower extremity chronic venous disease (CVD). Pregnancy-associated CVD is associated with changes in placental villi. We investigated angiogenesis and lymphangiogenesis in the placental villi of women with CVD during pregnancy compared with healthy controls with no history of CVD (HC). An observational, analytical, and prospective cohort study was conducted on 114 women in their third trimester of pregnancy (32 weeks). Sixty-two participants were clinically diagnosed with CVD. In parallel, 52 controls with no history of CVD (HC) were studied. Gene and protein expression of CD31, podoplanin (D2-40), Flt-1, and placental growth factor (PIGF) was analysed by real-time polymerase chain reaction (RT-qPCR) and immunohistochemistry. CD31 and D2-40 gene expression was significantly greater in the placental villi of women with CVD, as were the numbers of vessels positive for CD31 and D2-40. Significantly higher gene and protein expression of Flt-1 and PIGF was observed in the placental villi of women with CVD. Histological analysis showed more placental villi with periodic acid of Schiff (PAS)-positive material in women with CVD. Our results show a connection between pregnancy-associated CVD and leading to higher proangiogenic and lymphangiogenic activity in placental villi.