sFlt-1/PlGF for prediction of early-onset pre-eclampsia: STEPS (Study of Early Pre-eclampsia in Spain)

Reference Range Determination for the sFlt-1/PlGF Ratio in a Diverse Cohort of Pregnant Women in the United States

BACKGROUND

The serum soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) ratio is an established tool for predicting preeclampsia in many countries but is not widely adopted in the United States. This study aimed to determine reference ranges for the Elecsys® sFlt-1/PlGF ratio and the sFlt-1 and PlGF immunoassays (Roche Diagnostics International Ltd) in a diverse US population of healthy pregnant women.

METHODS

This was a prospective, noninterventional sample and data collection study performed between November 2022 and November 2023 at 9 collection sites and one measurement site in the United States. Evaluable women were ≥18 years old, apparently healthy, between 23 + 0 to 40 + 6 gestational weeks with a singleton pregnancy and had one serum sample collected. Reference ranges for 23 + 0 to 40 + 6 gestational weeks and 5 gestational windows within this range were determined using a nonparametric method.

RESULTS

Of 818 recruited women, 561 were evaluable for the analysis and were representative of the US population in terms of self-reported race, ethnicity, and maternal age. Reference ranges for the sFlt-1/PlGF ratio, as determined by the 2.5th and 97.5th percentiles (90% CIs), were 0.9 (0.7, 1.0) to 13.5 (11.6, 14.9) for a US intended use population at 23 + 0 to 34 + 6 gestational weeks (n = 380) and 0.9 (0.7, 1.1) to 40.8 (29.0, 47.2) for the entire evaluable population at 23 + 0 to 40 + 6 gestational weeks.

CONCLUSIONS

Reference ranges were determined for sFlt-1/PlGF and the sFlt-1 and PlGF immunoassays in a diverse, healthy US population of pregnant women at 23 + 0 to 40 + 6 gestational weeks.

A nomogram based on peripheral blood count between 12 and 18 weeks of gestation for predicting early-onset pre-eclampsia in pregnant women: a retrospective case-control study

BACKGROUND

Early-onset pre-eclampsia (PE), which delivered before 34 weeks of gestation, is associated with high maternal and pediatric morbidity and mortality. Several studies have examined predictive factors and models to identify individuals at risk for early-onset pre-eclampsia. However, implementing these methods often requires additional tests and increases the financial burden on pregnant women. Our study aimed to determine if early-onset PE development could be predicted using a simple, convenient, and easily accessible test: the peripheral blood count.

METHODS

In this study, we conducted a review of pregnant women who received routine prenatal visit and delivered in our hospital from April 2019 to April 2022. For each patient with PE, we matched them 1:1 with healthy pregnant women who were similar in terms of age, parity, and pre-gestational BMI. We gathered routine peripheral blood cell results between 12 and 18 weeks of gestation and utilized multivariate logistic regression to determine independent risk factors. Subsequently, a nomogram was created to forecast the likelihood of early-onset pre-eclampsia. Lastly, we assessed the model's predictive performance.

RESULTS

In our study, a total of 254 patients with PE were included, comprising of 41 patients with early-onset PE and 213 patients with late-onset PE, as well as 254 cases of normotensive pregnancy. The nomogram included four risk factors: mean corpuscular hemoglobin concentration (MCHC) ≥ 340.50 g/l, neutrophil-to-lymphocyte ratio (NLR) ≤ 4.40, platelet-to-lymphocyte ratio (PLR) ≤ 118.01, and platelet-to-mean platelet volume (PC/MPV) ≤ 17.81. Notably, the nomogram exhibited good diagnostic performance with an area under the curve (AUC) of 0.874, sensitivity of 95.1%, and specificity of 62.2%. Furthermore, the nomogram was validated through a decision curve analysis (DCA), which demonstrated a favorable positive net benefit, and the calibration curve showed a good fit and alignment with the ideal curve.

CONCLUSIONS

Our nomogram, based on four predictors derived from peripheral blood cells and related ratios, offers a practical screening tool for early-onset PE in pregnant women.

Prediction of Fetal Death in Preterm Preeclampsia Using Fetal Sex, Placental Growth Factor and Gestational Age

BACKGROUND/OBJECTIVES

Preeclampsia (PE) is a systemic disease that affects 4.6% of pregnancies. Despite the existence of a first-trimester screening for the prediction of preterm PE, no consensus exists regarding neither the right moment to end the pregnancy nor the appropriate variables to estimate the prognosis. The objective of this study was to obtain a prediction model for perinatal death in patients with preterm PE, useful for clinical practice.

METHODS

Singleton pregnant women with PE and preterm delivery were included in an observational retrospective study. Multiple maternal and fetal variables were collected, and several multivariable logistic regression analyses were applied to construct models to predict perinatal death, selecting the most accurate and reproducible according to the highest area under the curve (AUC) and the lowest Akaike Information Criteria (AIC).

RESULTS

A group of 148 pregnant women were included, and 18 perinatal deaths were registered. Univariable logistic regression selected as statistically significant variables the following: gestational age (GA) at admission, fetal sex, poor response to antihypertensive drugs, PlGF, umbilical artery (UA) pulsatility index (PI), cerebroplacental ratio (CPR), and absent/reversed ductus venosus (DV). The multivariable model, including all these parameters, presented an AUC of 0.95 and an AIC of 76.5. However, a model including only GA and fetal sex presented a similar accuracy with the highest simplicity (AUC 0.93, AIC 67.6). Finally, in fetuses with a similar GA, fetal death became dependent on PlGF and fetal sex, underlying the role of fetal sex in all circumstances.

CONCLUSIONS

Female fetal sex and low PlGF are notorious predictors of perinatal death in preterm PE, only surpassed by early GA at birth.

sFlt-1 impairs neurite growth and neuronal differentiation in SH-SY5Y cells and human neurons

Pre-eclampsia (PE) is a hypertensive disorder of pregnancy which is associated with increased risk of neurodevelopmental disorders in exposed offspring. The pathophysiological mechanisms mediating this relationship are currently unknown, and one potential candidate is the anti-angiogenic factor soluble Fms-like tyrosine kinase 1 (sFlt-1), which is highly elevated in PE. While sFlt-1 can impair angiogenesis via inhibition of VEGFA signalling, it is unclear whether it can directly affect neuronal development independently of its effects on the vasculature. To test this hypothesis, the current study differentiated the human neural progenitor cell (NPC) line ReNcell® VM into a mixed culture of mature neurons and glia, and exposed them to sFlt-1 during development. Outcomes measured were neurite growth, cytotoxicity, mRNA expression of nestin, MBP, GFAP, and βIII-tubulin, and neurosphere differentiation. sFlt-1 induced a significant reduction in neurite growth and this effect was timing- and dose-dependent up to 100 ng/ml, with no effect on cytotoxicity. sFlt-1 (100 ng/ml) also reduced βIII-tubulin mRNA and neuronal differentiation of neurospheres. Undifferentiated NPCs and mature neurons/glia expressed VEGFA and VEGFR-2, required for endogenous autocrine and paracrine VEGFA signalling, while sFlt-1 treatment prevented the neurogenic effects of exogenous VEGFA. Overall, these data provide the first experimental evidence for a direct effect of sFlt-1 on neurite growth and neuronal differentiation in human neurons through inhibition of VEGFA signalling, clarifying our understanding of the potential role of sFlt-1 as a mechanism by which PE can affect neuronal development.

Preeclampsia prediction model using demographic, clinical, and sonographic data in the second trimester of Japanese nulliparous women

AIM

This study aimed to clarify the factors influencing preeclampsia (PE) development in nulliparous Japanese women and to develop a PE prediction model using second trimester sonographic and clinical data readily available to obstetricians.

METHODS

This historical cohort study examined the obstetric records of nulliparous women who delivered at Yamanashi Prefectural Central Hospital from January 2019 to May 2023. A model was constructed to predict the PE development rate, with a focus on 796 nulliparous women. The assessed outcome was PE, excluding superimposed PE. Data on maternal age, assisted reproductive technology, mean arterial pressure, uterine artery notching, and umbilical artery resistance index were extracted. Multivariable logistic regression analysis was conducted on these five factors.

RESULTS

The incidence of PE was 4.3% (34/796). Multivariable analysis indicated significant odds ratios for the association of PE with mean arterial pressure (adjusted odds ratio: 1.06, 95% confidence interval: 1.03-1.10) and uterine artery notching (adjusted odds ratio: 6.28, 95% confidence interval: 2.82-14.0) in nulliparous women. The PE prediction formula was established as follows: Probability of PE development (%) = (odds/1 + odds) × 100, odds = ex and x = -11.3 + 0.039 × maternal age (years) + 0.91 × assisted reproductive technology + 0.061 × mean arterial pressure (mmHg) + 1.84 × uterine artery notching + 1.84 × umbilical artery resistance index. The sensitivity and specificity of this model were 58.8% and 84.5%, respectively (area under the curve: 0.79).

CONCLUSIONS

This study is the first to provide a prediction formula targeting the Japanese population. Our specialized model for nulliparous women could guide obstetricians to educate women regarding the precise prospect of PE development.

Longitudinal 8-Epi-Prostaglandin F2-Alpha and Angiogenic Profile Mediator Evaluation during Pregnancy in Women with Suspected or Confirmed Pre-eclampsia

Background: In this exploratory study, we aimed to evaluate the dynamics of angiogenic [soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), soluble Endoglin (sEng), and sFlt-1/PlGF, PlGF/sFlt-1, and sEng/PlGF ratios] and oxidative stress [8-epi-prostaglandin F2 alpha (8-epi-PGF2α) and 8-epi-PGF2α/PlGF ratio] mediator levels in women with suspected or confirmed pre-eclampsia (PE) at least two times during pregnancy. We also wanted to identify the possible correlations between 8-epi-PGF2α and angiogenic mediator levels at the time of inclusion of pregnant women. Methods: We included 40 pregnant women with suspected or confirmed PE, with a mean age of 29 years (range between 18 and 41 years) and gestational age between 18 and 28 weeks at inclusion in this study. The Enzyme-Linked Immunosorbent Assay (ELISA) method to measure the levels of serum angiogenic and oxidative stress mediators was used. Results: The evaluation of baseline sFlt-1/PlGF ratios using a cut-off of 38 suggested that 25 pregnant women had a sFlt-1/PlGF ratio of >38 (sFlt-1/PlGF ratio of >38 group) and 15 had a sFlt-1/PlGF ratio of ≤38 (sFlt-1/PlGF ratio of ≤38 group). The increases in sFlt-1/PlGF ratio in the sFlt-1/PlGF ratio of >38 group were caused by both an increase in sFlt-1 (2.04-fold) and a decrease in PlGF levels (2.55-fold). The 8-epi-PGF2α median levels were higher in the sFlt-1/PlGF ratio of >38 group (1.62-fold). During follow-up after pregnancy, we observed that the mean values of sFlt-1 and sEng and the median values of 8-epi-PGF2α and sFlt-1/PlGF, sEng/PlGF, and 8-epi-PGF2α/PlGF ratios increased directly proportional to gestational age for each measurement time until delivery in both groups. For five women who had a sFlt-1/PlGF ratio ≤38 at inclusion, sFlt-1/PlGF ratio was observed to increase to >38 later in pregnancy. We observed that, in the sFlt-1/PlGF ratio >38 group, baseline 8-epi-PGF2α levels better correlated with angiogenic mediator levels. Conclusions: Our study shows that 33.33% of pregnant women evaluated for suspected or confirmed PE with a sFlt-1/PlGF ratio of ≤38 displayed a rise in sFlt-1/PlGF ratio in subsequent weeks. In addition, together with angiogenic mediators, 8-epi-PGF2 α can be utilized as an independent predictor factor to help clinicians identify or predict which pregnant women will develop PE.

Serum protein profile analysis via label-free quantitation proteomics in patients with early-onset preeclampsia

BACKGROUND

Preeclampsia (PE) is a serious pregnancy complication, resulting in potentially life-threatening conditions for both mother and foetus. It is worth noting that early-onset PE has become a great challenge for clinicians due to its complex manifestation, rapid progression and serious complications. This study aims to investigate differential serum proteome profiles in patients with early-onset PE.

METHODS

Each serum sample was separated using a nanoliter flow rate Easy-nLC chromatography system. Then the samples were analysed by mass spectrometry. Bioinformatics analyses were conducted to analyse the functional categories or signal transduction pathways for differentially abundant proteins. Key proteins identified by mass spectrometry were verified by ELISA.

RESULTS

We found 30 and 34 proteins were upregulated and downregulated in early-onset PE patients (n = 3) vs controls (n = 3), respectively. Functional enrichment analysis revealed differentially expressed proteins related to the immune response and regulation of peptidase activity. ELISA confirmed that there were lower CSH1 levels and higher LPA concentrations in the serum samples of early-onset PE patients (n = 22) than in healthy controls (n = 19) (p < 0.05 for CSH1 and p < 0.001 for LPA).

CONCLUSIONS

This study revealed the critical features of serum proteins in early-onset PE patients. LPA and CSH1 may serve as biomarkers for early-onset PE diagnosis and therapy.

Maternal birth weight as an indicator of early-onset and late-onset hypertensive disorders of pregnancy: The Japan Environment and Children's study

OBJECTIVES

This study aimed to investigate the association between maternal birth weight (MBW) and hypertensive disorders of pregnancy (HDP) according to the gestational age when HDP develops.

STUDY DESIGN

A total of 77,345 subjects were included in this prospective birth cohort study. The association between MBW and HDP was investigated by a multinomial logistic regression model.

MAIN OUTCOME MEASURES

Early-onset HDP (EO-HDP), preterm late-onset HDP (preterm LO-HDP), and term late-onset HDP (term LO-HDP).

RESULTS

Lower MBW was associated with higher odds of preterm and term LO-HDP (p-values for trend < 0.0001 and = 0.0005, respectively). A linear association between MBW and EO-HDP was observed (p-values for trend = 0.0496). The shape of the association between MBW and preterm LO-HDP was a combination of the associations between MBW with EO-HDP or LO-HDP. The effect size of the association between MBW < 2,500 g and EO-HDP was lower than that of MBW < 2,500 g with preterm or term LO-HDP. The adjusted odds ratios for EO-HDP, preterm LO-HDP, and term LO-HDP in subjects with MBW < 2,500 g were 1.052 (95 % confidence interval [CI]: 0.665-1.664), 1.745 (95 % CI: 1.220-2.496), and 1.496 (95 % CI: 1.154-1.939), respectively.

CONCLUSIONS

MBW was associated with HDP, regardless of gestational age when HDP developed. Furthermore, the association of MBW < 2,500 g with preterm or term LO-HDP was stronger than that with EO-HDP.

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.

The Current Role of the sFlt-1/PlGF Ratio and the Uterine-Umbilical-Cerebral Doppler Ultrasound in Predicting and Monitoring Hypertensive Disorders of Pregnancy: An Update with a Review of the Literature

Regarding the hypertensive disorders of pregnancy, pre-eclampsia (PE) remains one of the leading causes of severe and life-threatening maternal and fetal complications. Screening of early-onset PE (<34 weeks of pregnancy), as well as late-onset PE (≥34 weeks), shows poor performance if based solely on clinical features. In recent years, biochemical markers from maternal blood-the pro-angiogenic protein placental growth factor (PlGF) and the antiangiogenic protein soluble FMS-like tyrosine kinase 1 (sFlt-1)-and Doppler velocimetry indices-primarily the mean uterine pulsatility index (PI), but also the uterine resistivity index (RI), the uterine systolic/diastolic ratio (S/D), uterine and umbilical peak systolic velocity (PSV), end-diastolic velocity (EDV), and uterine notching-have all shown improved screening performance. In this review, we summarize the current status of knowledge regarding the role of biochemical markers and Doppler velocimetry indices in early prediction of the onset and severity of PE and other placenta-related disorders, as well as their role in monitoring established PE and facilitating improved obstetrical surveillance of patients categorized as high-risk in order to prevent adverse outcomes. A sFlt-1/PlGF ratio ≤ 33 ruled out early-onset PE with 95% sensitivity and 94% specificity, whereas a sFlt-1/PlGF ≥88 predicted early-onset PE with 88.0% sensitivity and 99.5% specificity. Concerning the condition's late-onset form, sFlt-1/PlGF ≤ 33 displayed 89.6% sensitivity and 73.1% specificity in ruling out the condition, whereas sFlt-1/PlGF ≥ 110 predicted the condition with 58.2% sensitivity and 95.5% specificity. The cut-off values of the sFlt-1/PlGF ratio for the screening of PE were established in the PROGNOSIS study: a sFlt-1/PlGF ratio equal to or lower than 38 ruled out the onset of PE within one week, regardless of the pregnancy's gestational age. The negative predictive value in this study was 99.3%. In addition, sFlt-1/PlGF > 38 showed 66.2% sensitivity and 83.1% specificity in predicting the occurrence of PE within 4 weeks. Furthermore, 2018 ISUOG Practice Guidelines stated that a second-trimester mean uterine artery PI ≥ 1.44 increases the risk of later PE development. The implementation of a standard screening procedure based on the sFlt-1/PlGF ratio and uterine Doppler velocimetry may improve early detection of pre-eclampsia and other placenta-related disorders.

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.

Angiogenic imbalance in pre-eclampsia and fetal growth restriction: enhanced soluble fms-like tyrosine kinase-1 binding or diminished production of placental growth factor?

OBJECTIVES

To assess levels of total placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and free PlGF in women with pre-eclampsia (PE) with or without a small-for-gestational-age (SGA) neonate in order to establish whether low free PlGF levels associated with PE and SGA are due to enhanced sFlt-1 binding or decreased PlGF production.

METHODS

This was a secondary analysis of a prospective multicenter cohort study involving 407 pregnancies with suspected or confirmed PE, in which total PlGF levels were calculated from measured sFlt-1 and free PlGF levels. The control group included women who were suspected to have PE at a certain point in pregnancy but did not develop PE. The analysis was stratified according to whether PE was early- or late-onset (gestational age < 34 weeks vs ≥ 34 weeks) and according to the presence of SGA at birth, which was used as a proxy of fetal growth restriction in the absence of Doppler ultrasound and biometric data.

RESULTS

In early-onset PE, both women with and those without SGA had lower free (19 and 45 pg/mL) and total (44 and 100 pg/mL) PlGF levels compared with women without PE (free and total PlGF, 300 and 381 pg/mL, respectively). SGA alone did not affect free and total PlGF in this condition (free and total PlGF, 264 and 352 pg/mL, respectively). Observations in women with late-onset PE were similar, although the changes were more modest. Both SGA (gestational age < 34 weeks) and PE were individually associated with increased sFlt-1 and, in women with both PE and SGA, the upregulation of sFlt-1 occurred in a synergistic manner, thus resulting in the highest sFlt-1/free PlGF ratio in this group. This occurred in both early- and late-onset PE.

CONCLUSIONS

Particularly in pregnancies with early-onset PE and SGA, diminished PlGF production is an important cause of low free PlGF levels. Under such conditions, sFlt-1 lowering is unlikely to restore the angiogenic balance. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Clinical utility of sFlt-1 and PlGF in screening, prediction, diagnosis and monitoring of pre-eclampsia and fetal growth restriction

Pre-eclampsia (PE) is characterized by placental and maternal endothelial dysfunction, and associated with fetal growth restriction (FGR), placental abruption, preterm delivery and stillbirth. The angiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are altered in pregnancies complicated by placenta-related disorders. In this Review, we summarize the existing knowledge, examining the performance of maternal PlGF, sFlt-1 and the sFlt-1/PlGF ratio for screening PE, predicting development of PE in the short term, diagnosing PE, monitoring established PE and predicting other placenta-related disorders in singleton pregnancy. We also discuss the performance of PlGF and the sFlt-1/PlGF ratio for predicting PE in twin pregnancy. For first-trimester screening in singleton pregnancy, a more accurate way of identifying high-risk women than current practice is to combine maternal PlGF levels with clinical risk factors and ultrasound markers. Later in pregnancy, the sFlt-1/PlGF ratio has advantages over PlGF because it has a higher pooled sensitivity and specificity for diagnosing and monitoring PE. It has clinical value because it can rule out the development of PE in the 1-4-week period after the test. Once a diagnosis of PE is established, repeat measurement of sFlt-1 and PlGF can help monitor progression of the condition and may inform clinical decision-making regarding the optimal time for delivery. The sFlt-1/PlGF ratio is useful for predicting FGR and preterm delivery, but the association between stillbirth and the angiogenic factors is unclear. The sFlt-1/PlGF ratio can be used to predict PE in twin pregnancy, although different sFlt-1/PlGF ratio cut-offs from those for singleton pregnancy should be applied for optimal performance. In summary, PlGF, sFlt-1 and the sFlt-1/PlGF ratio are useful for screening, diagnosing, predicting and monitoring placenta-related disorders in singleton and twin pregnancy. We propose that tests for these angiogenic factors are integrated more fully into clinical practice.© 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Establishment and validation of a predictive model of preeclampsia based on transcriptional signatures of 43 genes in decidua basalis and peripheral blood

Preeclampsia (PE) has an increasing incidence worldwide, and there is no gold standard for prediction. Recent progress has shown that abnormal decidualization and impaired vascular remodeling are essential to PE pathogenesis. Therefore, it is of great significance to analyze the decidua basalis and blood changes of PE to explore new methods. Here, we performed weighted gene co-expression network analysis based on 9553 differentially expressed genes of decidua basalis data (GSE60438 includes 25 cases of PE and 23 non-cases) from Gene Expression Omnibus to screen relevant module-eigengenes (MEs). Among them, MEblue and MEgrey are the most correlated with PE, which contains 371 core genes. Subsequently, we applied the logistic least absolute shrinkage and selection operator regression, screened 43 genes most relevant to prediction from the intersections of the 371 genes and training set (GSE48424 includes 18 cases of PE and 18 non-cases) genes, and built a predictive model. The specificity and sensitivity are illustrated by receiver operating characteristic curves, and the stability was verified by two validation sets (GSE86200 includes 12 cases of PE and 48 non-cases, and GSE85307 includes 47 cases of PE and 110 non-cases). The results demonstrated that our predictive model shows good predictions, with an area under the curve of 0.991 for the training set, 0.874 and 0.986 for the validation sets. Finally, we found the 43 key marker genes in the model are closely associated with the clinically accepted predictive molecules, including FLT1, PIGF, ENG and VEGF. Therefore, this predictive model provides a potential approach for PE diagnosis and treatment.

The effect of genistein on IGF-1, PlGF, sFLT-1 and fetoplacental development

The mechanisms by which genistein, a phytoestrogen, affects fetoplacental development adversely are still poorly understood. It is reported that genistein ingestion modulates thyroid functions, leptin hormone, C-reactive protein, and thyroxin kinase activities. In this study, we evaluated changes in serum and placental insulin-like growth factor-I (IGF-1), placental growth factor (PIGF), and soluble fms-like tyrosine kinase-1 (sFLT-1) in pregnant rats exposed to genistein using ELISA. According to the treatments, Rats were divided into control, 2 mg genistein, and 4 mg genistein groups. Genistein groups were administered with the doses orally from gestational day (GD) one onwards until sacrifice, while the control group received an equal volume of distilled water the vehicle. At GD-12, GD-16, and GD-20, serum samples and placenta homogenates were prepared from maternal blood samples and the placenta and were analysed to determine the concentration of IGF-1, sFLT-1, and PIGF. Serum IGF-1 and PIGF were both increased in all genistein groups at GD-12 and GD-16, and at GD-20 in the 4 mg group. However, serum IGF-1and PIGF levels were decreased in the placenta from all genistein groups at GD-20. Placenta sFLT-1 levels increased at both GD-16 and GD-20 in genistein-treated rat serum. An initial decrease in placental sFLT-1 at GD-12 was followed by an increase at GD-16 and finally a decrease at GD-20 in all genistein-treated rats. The sFL-1/PlGF ratio in placenta samples of genistein-exposed rats was decreased at GD-16 and increased at GD-20, while the reverse was recorded in the serum sample at the same gestational periods. The fetoplacental growth disruption mechanism of genistein can be partly explained by its interference with placental growth factor signalling.

Screening high-risk population of persistent postpartum hypertension in women with preeclampsia using latent class cluster analysis

BACKGROUND

A significant proportion of women with preeclampsia (PE) exhibit persistent postpartum hypertension (PHTN) at 3 months postpartum associated with cardiovascular morbidity. This study aimed to screen patients with PE to identify the high-risk population with persistent PHTN.

METHODS

This retrospective cohort study enrolled 1,000 PE patients with complete parturient and postpartum blood pressure (BP) profiles at 3 months postpartum. The enrolled patients exhibited new-onset hypertension after 20 weeks of pregnancy, while those with PE superimposed upon chronic hypertension were excluded. Latent class cluster analysis (LCCA), a method of unsupervised learning in machine learning, was performed to ascertain maternal exposure clusters from eight variables and 35 subordinate risk factors. Logistic regression was applied to calculate odds ratios (OR) indicating the association between clusters and PHTN.

RESULTS

The 1,000 participants were classified into three exposure clusters (subpopulations with similar characteristics) according to persistent PHTN development: high-risk cluster (31.2%), medium-risk cluster (36.8%), and low-risk cluster (32.0%). Among the 1,000 PE patients, a total of 134 (13.4%) were diagnosed with persistent PHTN, while the percentages of persistent PHTN were24.68%, 10.05%, and 6.25% in the high-, medium-, and low-risk clusters, respectively. Persistent PHTN in the high-risk cluster was nearly five times higher (OR, 4.915; 95% confidence interval (CI), 2.92-8.27) and three times (OR, 2.931; 95% CI, 1.91-4.49) than in the low- and medium-risk clusters, respectively. Persistent PHTN did not differ between the medium- and low-risk clusters. Subjects in the high-risk cluster were older and showed higher BP, poorer prenatal organ function, more adverse pregnancy events, and greater medication requirement than the other two groups.

CONCLUSION

Patients with PE can be classified into high-, medium-, and low-risk clusters according to persistent PHTN severity; each cluster has cognizable clinical features. This study's findings stress the importance of controlling persistent PHTN to prevent future cardiovascular disease.

Association of sFlt-1 and C-reactive protein with outcomes in severe preeclampsia: A cohort study

ABSTRACT

To determine the association between soluble FMS-like tyrosine kinase-1 (sFlt-1) and high-sensitivity C-reactive protein (hs-CRP) with maternal and perinatal outcomes in patients with preeclampsia (PE) with severe features.A cohort study was conducted on 100 patients, 60 with PE with severe features, and 40 healthy women in the third trimester of pregnancy. Admission serum levels of sFlt-1 and hs-CRP and clinical and epidemiological parameters were evaluated to quantify the predictive ability of adverse maternal and perinatal outcomes using hierarchical multiple regression and receiver operating characteristic curves.Compared to controls, patients with PE and severe features had significantly higher levels of sFlt-1 but not hs-CRP. sFlt-1 and hs-CRP proved to be reasonable parameters for the prediction of composite adverse maternal outcomes. However, we found no correlation between these 2 biomarkers. PE integrated estimate of risk scores were correlated only with sFlt-1 levels. Regarding fetal outcomes, unlike hs-CRP, sFlt-1 was strongly associated with birth weight and Apgar score < 7 at 5 minutes. Following multivariate analysis, maternal age, previous hypertension, sFlt-1, and hs-CRP levels remained independently associated with composite adverse maternal outcomes.sFlt-1 levels were elevated in patients with PE and severe features. Both sFlt-1 and hs-CRP may predict composite adverse maternal outcomes but do not correlate with each other and differ in perinatal morbidity patterns. These data support the hypothesis that the varied outcomes in PE may result from different pathogenic pathways.

SARS- CoV-2 infection and oxidative stress in early-onset preeclampsia

SARS-CoV-2 causes coronavirus disease 2019 (COVID-19) also in pregnant women. Infection in pregnancy leads to maternal and placental functional alterations. Pregnant women with vascular defects such as preeclampsia show high susceptibility to SARS-CoV-2 infection by undefined mechanisms. Pregnant women infected with SARS-CoV-2 show higher rates of preterm birth and caesarean delivery, and their placentas show signs of vasculopathy and inflammation. It is still unclear whether the foetus is affected by the maternal infection with this virus and whether maternal infection associates with postnatal affections. The SARS-CoV-2 infection causes oxidative stress and activation of the immune system leading to cytokine storm and next tissue damage as seen in the lung. The angiotensin-converting-enzyme 2 expression is determinant for these alterations in the lung. Since this enzyme is expressed in the human placenta, SARS-CoV-2 could infect the placenta tissue, although reported to be of low frequency compared with maternal lung tissue. Early-onset preeclampsia (eoPE) shows higher expression of ADAM17 (a disintegrin and metalloproteinase 17) causing an imbalanced renin-angiotensin system and endothelial dysfunction. A similar mechanism seems to potentially account for SARS-CoV-2 infection. This review highlights the potentially common characteristics of pregnant women with eoPE with those with COVID-19. A better understanding of the mechanisms of SARS-CoV-2 infection and its impact on the placenta function is determinant since eoPE/COVID-19 association may result in maternal metabolic alterations that might lead to a potential worsening of the foetal programming of diseases in the neonate, young, and adult.

Gene Expression Network Analysis Identifies Potential Targets for Prevention of Preeclampsia

Objective

Preeclampsia (PE) is a pregnancy-specific multisystem disease as well as an important cause of maternal and perinatal death. This study aimed to analyze the placental transcriptional data and clinical information of PE patients available in the published database and predict the target genes for prevention of PE.

Methods

The clinical information and corresponding RNA data of PE patients were downloaded from the GEO database. Cluster analysis was performed to examine the correlation between different genotyping genes and clinical manifestations. Then, bioinformatic approaches including GO, KEGG, WGCNA, and GSEA were employed to functionally characterize candidate target genes involved in pathogenesis of PE.

Results

Two PE datasets GSE60438 and GSE75010 were obtained and combined, thereby providing the data of 205 samples in total (100 non-PE and 105 PE samples). After eliminating the batch effect, we grouped and analyzed the integrated data, and further performed GSEA analysis. It was found that the genes in group 1 and group 2 were different from those in normal samples. Moreover, WGCNA analysis revealed that genes in group 1 were up-regulated in turquoise module, including SASH1, PIK3CB and FLT-1, while genes in group 2 were up-regulated in the blue and brown modules. We further conducted GO and KEGG pathway enrichment analyses and found that the differential genes in turquoise module were mainly involved in biological processes such as small molecular catabolic process, while being highly enriched in pathways, including MAPK signaling pathway and Rap1 signaling pathway.

Conclusion

FLT-1 was conventionally used to predict PE risk, and sFLT-1 could also be used as an indicator to evaluate PE treatment effect. As a candidate biomarker for predicting PE, SASH1 may participate in proliferation, migration, invasion and epithelial mesenchymal transformation of human trophoblast cells by regulating MAPK pathway and Rap1 signaling pathway, thus affecting the progression of PE. The mechanism allowing PIK3CB to regulate PE development was not clear, while the gene could be another candidate biomarker for PE risk prediction. This is an exploratory study and our findings were still required verification in further studies.

Prediction of preeclampsia throughout gestation with maternal characteristics and biophysical and biochemical markers: a longitudinal study

BACKGROUND

The current approach to predict preeclampsia combines maternal risk factors and evidence from biophysical markers (mean arterial pressure, Doppler velocimetry of the uterine arteries) and maternal blood proteins (placental growth factor, soluble vascular endothelial growth factor receptor-1, pregnancy-associated plasma protein A). Such models require the transformation of biomarker data into multiples of the mean values by using population- and site-specific models. Previous studies have focused on a narrow window in gestation and have not included the maternal blood concentration of soluble endoglin, an important antiangiogenic factor up-regulated in preeclampsia.

OBJECTIVE

This study aimed (1) to develop models for the calculation of multiples of the mean values for mean arterial pressure and biochemical markers; (2) to build and assess the predictive models for preeclampsia based on maternal risk factors, the biophysical (mean arterial pressure) and biochemical (placental growth factor, soluble vascular endothelial growth factor receptor-1, and soluble endoglin) markers collected throughout pregnancy; and (3) to evaluate how prediction accuracy is affected by the presence of chronic hypertension and gestational age.

STUDY DESIGN

This longitudinal case-cohort study included 1150 pregnant women: women without preeclampsia with (n=49) and without chronic hypertension (n=871) and those who developed preeclampsia (n=166) or superimposed preeclampsia (n=64). Mean arterial pressure and immunoassay-based maternal plasma placental growth factor, soluble vascular endothelial growth factor receptor-1, and soluble endoglin concentrations were available throughout pregnancy (median of 5 observations per patient). A prior-risk model for preeclampsia was established by using Poisson regression based on maternal characteristics and obstetrical history. Next, multiple regression was used to fit biophysical and biochemical marker data as a function of maternal characteristics by using data collected at 8 to 15⁺⁶, 16 to 19⁺⁶, 20 to 23⁺⁶, 24 to 27⁺⁶, 28 to 31⁺⁶, and 32 to 36⁺⁶ week intervals, and observed values were converted into multiples of the mean values. Then, multivariable prediction models for preeclampsia were fit based on the biomarker multiples of the mean data and prior-risk estimates. Separate models were derived for overall, preterm, and term preeclampsia, which were evaluated by receiver operating characteristic curves and sensitivity at fixed false-positive rates.

RESULTS

(1) The inclusion of soluble endoglin in prediction models for all preeclampsia, together with the prior-risk estimates, mean arterial pressure, placental growth factor, and soluble vascular endothelial growth factor receptor-1, increased the sensitivity (at a fixed false-positive rate of 10%) for early prediction of superimposed preeclampsia, with the largest increase (from 44% to 54%) noted at 20 to 23⁺⁶ weeks (McNemar test, P<.05); (2) combined evidence from prior-risk estimates and biomarkers predicted preterm preeclampsia with a sensitivity (false-positive rate, 10%) of 55%, 48%, 62%, 72%, and 84% at 8 to 15⁺⁶, 16 to 19⁺⁶, 20 to 23⁺⁶, 24 to 27⁺⁶, and 28 to 31⁺⁶ week intervals, respectively; (3) the sensitivity for term preeclampsia (false-positive rate, 10%) was 36%, 36%, 41%, 43%, 39%, and 51% at 8 to 15⁺⁶, 16 to 19⁺⁶, 20 to 23⁺⁶, 24 to 27⁺⁶, 28 to 31⁺⁶, and 32 to 36⁺⁶ week intervals, respectively; (4) the detection rate for superimposed preeclampsia among women with chronic hypertension was similar to that in women without chronic hypertension, especially earlier in pregnancy, reaching at most 54% at 20 to 23⁺⁶ weeks (false-positive rate, 10%); and (5) prediction models performed comparably to the Fetal Medicine Foundation calculators when the same maternal risk factors and biomarkers (mean arterial pressure, placental growth factor, and soluble vascular endothelial growth factor receptor-1 multiples of the mean values) were used as input.

CONCLUSION

We introduced prediction models for preeclampsia throughout pregnancy. These models can be useful to identify women at risk during the first trimester who could benefit from aspirin treatment or later in pregnancy to inform patient management. Relative to prediction performance at 8 to 15⁺⁶ weeks, there was a substantial improvement in the detection rate for preterm and term preeclampsia by using data collected after 20 and 32 weeks' gestation, respectively. The inclusion of plasma soluble endoglin improves the early prediction of superimposed preeclampsia, which may be valuable when Doppler velocimetry of the uterine arteries is not available.

Prediction of pre-eclampsia-related complications in women with suspected or confirmed pre-eclampsia: development and internal validation of clinical prediction model

OBJECTIVE

A model that can predict reliably the risk of pre-eclampsia (PE)-related pregnancy complications does not exist. The aim of this study was to develop and validate internally a clinical prediction model to predict the risk of a composite outcome of PE-related maternal and fetal complications within 7, 14 and 30 days of testing in women with suspected or confirmed PE.

METHODS

The data for this study were derived from a prospective, multicenter, observational cohort study on women with a singleton pregnancy and suspected or confirmed PE at 20 to < 37 weeks' gestation. For the development of the prediction model, the possible contribution of clinical and standard laboratory variables, as well as the biomarkers soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF) and their ratio, in the prediction of a composite outcome of PE-related complications, consisting of maternal and fetal adverse events within 7, 14 and 30 days, was explored using multivariable competing-risks regression analysis. The discriminative ability of the model was assessed using the concordance (c-) statistic. A bootstrap validation procedure with 500 replications was used to correct the estimate of the prediction model performance for optimism and to compute a shrinkage factor for the regression coefficients to correct for overfitting.

RESULTS

Among 384 women with suspected or confirmed PE, 96 (25%) had an adverse PE-related outcome at any time after hospital admission. Important predictors of adverse PE-related outcome included sFlt-1/PlGF ratio, gestational age at the time of biomarker measurement and protein-to-creatinine ratio as continuous variables. The c-statistics (corrected for optimism) for developing a PE-related complication within 7, 14 and 30 days were 0.89, 0.88 and 0.87, respectively. There was limited overfitting, as indicated by a shrinkage factor of 0.91.

CONCLUSIONS

We propose a simple clinical prediction model with good discriminative performance to predict PE-related complications. Determination of its usefulness in clinical practice awaits further investigation and external validation. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Model for Early Prediction of Preeclampsia: A Nested Case Controlled Study in Indian Women

Purpose

Preeclampsia (PE) affects 5-7% of the pregnancies worldwide, and is one of the most dreaded disorders of pregnancy contributing to maternal and neonatal mortality. PE is mostly presented in the third trimester of pregnancy. Here, we used serum placental growth factor (PIGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) to develop a model for predicting PE in Indian women in early second trimester.

Methods

In this case-control study, a total 1452 healthy pregnant women were recruited. Blood samples were collected at the following gestational weeks (GWs), 12-20 (GW1), 21-28 (GW2) and 29-term (GW3), and post-delivery. Body mass index (BMI) was calculated by anthropometric measurements. Serum sFlt-1, PIGF and VEGF were analyzed by ELISA. A predictive model for PE was developed using multivariable logistic regression analysis.

Results

In PE cases, serum PlGF and VEGF levels were significantly lower at each GW, while serum sFlt-1 was lower only at GW1, relative to age-matched controls, (n = 132/group). Age-matched comparison between PE cases and controls indicated that sFlt-1 was associated with decreased PE outcome (Odds ratio. OR = 0.988, CI = 0.982-0.993), whereas sFlt-1/PlGF ratio (OR = 1.577, CI = 1.344-1.920) and BMI (OR = 1.334, CI = 1.187-1.520) were associated with increased PE outcome. Logistic regression was used to develop a predictive model for PE at GW1. Using testing dataset, model was externally validated which resulted in 88% accuracy in predicting PE cases at 0.5 probability cutoff.

Conclusion

Prediction model using sFlt-1, sFlt-1/PlGF ratio and BMI may be useful to predict PE as early as 12-20 weeks in women with optimal sensitivity and specificity.

The ROBINS-I and the NOS had similar reliability but differed in applicability: A random sampling observational studies of systematic reviews/meta-analysis

OBJECTIVE

There is a lack of evidence on the usage of the quality assessment tool-the Risk Of Bias In Nonrandomized Studies-of Interventions (ROBINS-I). This article aimed to measure the reliability, criterion validity, and feasibility of the ROBINS-I and the Newcastle-Ottawa Scale (NOS).

METHODS

A sample of systematic reviews or meta-analyses of observational studies were selected from Medline (2013-2017) and assessed by two reviewers using ROBINS-I and the NOS. We reported on reliability in terms of the first-order agreement coefficient (AC1) statistic. Correlation coefficient statistic was used to explore the criterion validity of the ROBINS-I. We compared the feasibility of the ROBINS-I and NOS by recording the time to complete an assessment and the instances where assessing was difficult.

RESULTS

Five systematic reviews containing 41 cohort studies were finally included. Interobserver agreement on the individual domain of the ROBINS-I as well as the NOS was substantial with a mean AC1 statistic of 0.67 (95% CI: 0.50-0.83) and 0.73 (95% CI: 0.65-0.81), respectively. The criterion validity of the ROBNS-I was moderate (K = 0.52) against NOS. The time in assessing a single study by ROBINS-I varied from 7 hours initially to 3 hours compared with 30 minutes for the NOS. Both reviewers rated "bias due to departure from the intended interventions" the most time-consuming domain in the ROBINS-I, items in the NOS were equal.

CONCLUSIONS

The ROBINS-I and the NOS seem to provide the same reliability but vary in applicability. The over-complicated feature of ROBINS-I may limit its usage and a simplified version is needed.

Gestational Age-Specific Reference Ranges for the sFlt-1/PlGF Immunoassay Ratio in Twin Pregnancies

OBJECTIVE

Establish reference ranges for the Elecsys® soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) immunoassay ratio in twin pregnancies.

METHODS

Data analyzed were from 3 prospective studies: Prediction of Short-Term Outcome in Pregnant Women with Suspected Preeclampsia (PE) (PROGNOSIS), Study of Early-onset PE in Spain (STEPS), and a multicenter case-control study. Median, 5th, and 95th percentiles for sFlt-1, PlGF, and the sFlt-1/PlGF ratios were determined for normal twin pregnancies for 7 gestational windows and compared with the previous data for singleton pregnancies.

RESULTS

The reference range analysis included 269 women with normal twin pregnancies. Before 29 weeks' gestation, median, 5th, and 95th percentiles for sFlt-1/PlGF ratios did not differ between twin and singleton pregnancies. From 29 weeks' gestation to delivery, median, 5th, and 95th percentiles for sFlt-1/PlGF ratios were substantially higher in twin versus singleton pregnancies. sFlt-1 values were higher in women with twin pregnancies across all gestational windows. PlGF values were similar or higher in twin versus singleton pregnancies; PlGF concentrations increased from 10 weeks + 0 days to 28 weeks + 6 days' gestation.

CONCLUSIONS

Reference ranges for the sFlt-1/PlGF ratio are similar in women with twin and singleton pregnancies until 29 weeks' gestation but appear higher in twin pregnancies thereafter.

Economic evaluation of the sFlt-1/PlGF ratio for the short-term prediction of preeclampsia in a Japanese cohort of the PROGNOSIS Asia study

The PRediction of short-term Outcomes in preGNant wOmen with Suspected preeclampsIa Study (PROGNOSIS) Asia validated the use of the soluble fms-like tyrosine 1/placental growth factor (sFlt-1/PlGF) ratio cutoff value of ≤38 to rule out the occurrence of preeclampsia in the short term in Asian women. We assessed the economic impact of the introduction of the sFlt-1/PlGF ratio test for predicting preeclampsia in Japan using data from the Japanese cohort of PROGNOSIS Asia. The cost analysis was developed with estimates in either a no-test scenario, with clinical decisions based on standard diagnostic procedures alone, or a test scenario, in which the sFlt-1/PlGF ratio test was used in addition to standard diagnostic procedures. For both scenarios, rates of hospitalization and other test characteristics were obtained from the results for the Japanese cohort in PROGNOSIS Asia. The total cost per patient was the main outcome of this cost analysis model. Introduction of the sFlt-1/PlGF ratio test using a cutoff value of 38 resulted in a reduced hospitalization rate compared with the rate in the no-test scenario (14.4% versus 8.7%). The reduction in the rate of hospitalizations led to an estimated 16 373 JPY reduction in healthcare costs per patient. The sFlt-1/PlGF ratio test is likely to reduce the unnecessary hospitalization of women at low risk of developing preeclampsia in the short term while also identifying high-risk individuals requiring appropriate management. Reducing unnecessary hospitalizations would result in significant cost savings in the Japanese healthcare system.

The impact of advanced maternal age on pregnancy and offspring health: A mechanistic role for placental angiogenic growth mediators

The birth rates among women of advanced maternal age (AMA) have risen over the last two decades; yet, pregnancies with AMA are considered high-risk and are associated with a significant increase in pregnancy complications. Although the mechanisms leading to pregnancy complications in women with AMA are not fully understood, it has been well established in the literature that offspring exposed to unfavorable environmental conditions in utero, such as gestational diabetes, preeclampsia, and/or intrauterine growth restriction during the early stages of development are subject to long-term health consequences. Additionally, angiogenic growth mediators, which drive vascular development of the placenta, are imbalanced in pregnancies with AMA. These same imbalances also occur in pregnancies complicated by preeclampsia, gestational diabetes, and obesity. This review discusses the impact of AMA on pregnancy and offspring health, and the potential mechanistic role of placental angiogenic growth mediators in the development of pregnancy complications at AMA.

Maternal Morbidity and Mortality: Are We Getting to the "Heart" of the Matter?

Cardiovascular disease (CVD), including hypertensive disorders of pregnancy (HDP) and peripartum cardiomyopathy, is a leading cause of pregnancy-related death in the United States. Women who are African American or American Indian/Alaskan Native, have HDP, are medically underserved, are older, or are obese have a major risk for the onset and/or progression of CVD during and after pregnancy. Paradoxically, women with no preexisting chronic conditions or risk factors also experience significant pregnancy-related cardiovascular (CV) complications. The question remains whether substantial physiologic stress on the CV system during pregnancy reflected in hemodynamic, hematological, and metabolic changes uncovers subclinical prepregnancy CVD in these otherwise healthy women. Equally important and similarly understudied is the concept that women's long-term CV health could be detrimentally affected by adverse pregnancy outcomes, such as preeclampsia, gestational hypertension, and diabetes, and preterm birth. Thus, a critical life span perspective in the assessment of women's CV risk factors is needed to help women and health care providers recognize and appreciate not only optimal CV health but also risk factors present before, during, and after pregnancy. In this review article, we highlight new advancements in understanding adverse, pregnancy-related CV conditions and will discuss promising strategies or interventions for their prevention, diagnosis, and treatment.

Prediction of adverse maternal outcomes of early severe preeclampsia

OBJECTIVES

Assess soluble FMS-like tyrosine kinase-1/placental growth factor ratio (sFlt-1/PlGF) diagnostic accuracy for predicting adverse maternal outcome in patients with early severe preeclampsia, and whether its predictive performance is superior to full preeclampsia integrated estimate of risk score (PIERS).

STUDY DESIGN

Prospective study enrolled patients with early severe preeclampsia (defined by American College of Obstetricians and Gynaecologists 2013 guidelines) admitted to the Clinic for Obstetrics and Gynaecology, Clinical Center of Serbia intensive care unit. Patients underwent delivery to terminate preeclampsia within 48 h of admission. PIERS was generated and blood samples taken at admission. Multiple pregnancies and gestational ages outside 24-34 weeks were excluded. sFlt-1 and PlGF serum concentrations were measured using Elecsys® assays and cobas e 601 analyser. Maternal complications were recorded for seven days post-delivery.

MAIN OUTCOME MEASURES

Diagnostic accuracy (sensitivity and specificity), and predictive performance (receiver operating characteristic area under curve [AUC]) vs. PIERS, of sFlt-1/PlGF for predicting adverse maternal outcome.

RESULTS

Of 89 patients enrolled, 61 were evaluable. Median frequency of adverse maternal outcomes within seven days of delivery was two. Median sFlt-1/PlGF and PIERS were 521·0 and 5·0%, respectively. sFlt-1/PlGF showed greater correlation with complication number than PIERS (Spearman's rho: 0·728 [p < 0·001] and 0·134 [p = 0·304], respectively). AUC for sFlt-1/PlGF and PIERS were 0·853 and 0·628, respectively. A 377·0 sFlt-1/PlGF cut-off was optimal for predicting complications (75·0% sensitivity; 92·3% specificity).

CONCLUSIONS

sFlt-1/PlGF correlated more closely with number of adverse maternal outcomes than PIERS, and was a superior predictor of maternal complications.

Oxidative stress and mitochondrial dysfunction in early-onset and late-onset preeclampsia

Preeclampsia is a pregnancy-specific syndrome with multisystem involvement which leads to foetal, neonatal, and maternal morbidity and mortality. This syndrome is characterized by the onset of clinical signs and symptoms and delivery before (early-onset preeclampsia, eoPE), or after (late-onset preeclampsia, loPE), the 34 weeks of gestation. Preeclampsia is a mitochondrial disorder where its differential involvement in eoPE and loPE is unclear. Mitochondria regulate cell metabolism and are a significant source of reactive oxygen species (ROS). The syncytiotrophoblast in eoPE and loPE show altered mitochondrial structure and function resulting in ROS overproduction, oxidative stress, and cell damage and death. Mitochondrial dysfunction in eoPE may result from altered expression of several molecules, including dynamin-related protein 1 and mitofusins, compared with loPE where these factors are either reduced or unaltered. Equally, mitochondrial fusion/fission dynamics seem differentially modulated in eoPE and loPE. It is unclear whether the electron transport chain and oxidative phosphorylation are differentially altered in these two subgroups of preeclampsia. However, the activity of complex IV (cytochrome c oxidase) and the expression of essential proteins involved in the electron transport chain are reduced, leading to lower oxidative phosphorylation and mitochondrial respiration in the preeclamptic placenta. Interventional studies in patients with preeclampsia using the coenzyme Q₁₀, a key molecule in the electron transport chain, suggest that agents that increase the antioxidative capacity of the placenta may be protective against preeclampsia development. In this review, the mitochondrial dysfunction in both eoPE and loPE is summarized. Therapeutic approaches are discussed in the context of contributing to the understanding of mitochondrial dysfunction in eoPE and loPE.

Prediction of Preeclampsia and Intrauterine Growth Restriction: Development of Machine Learning Models on a Prospective Cohort

BACKGROUND

Preeclampsia and intrauterine growth restriction are placental dysfunction-related disorders (PDDs) that require a referral decision be made within a certain time period. An appropriate prediction model should be developed for these diseases. However, previous models did not demonstrate robust performances and/or they were developed from datasets with highly imbalanced classes.

OBJECTIVE

In this study, we developed a predictive model of PDDs by machine learning that uses features at 24-37 weeks' gestation, including maternal characteristics, uterine artery (UtA) Doppler measures, soluble fms-like tyrosine kinase receptor-1 (sFlt-1), and placental growth factor (PlGF).

METHODS

A public dataset was taken from a prospective cohort study that included pregnant women with PDDs (66/95, 69%) and a control group (29/95, 31%). Preliminary selection of features was based on a statistical analysis using SAS 9.4 (SAS Institute). We used Weka (Waikato Environment for Knowledge Analysis) 3.8.3 (The University of Waikato, Hamilton, NZ) to automatically select the best model using its optimization algorithm. We also manually selected the best of 23 white-box models. Models, including those from recent studies, were also compared by interval estimation of evaluation metrics. We used the Matthew correlation coefficient (MCC) as the main metric. It is not overoptimistic to evaluate the performance of a prediction model developed from a dataset with a class imbalance. Repeated 10-fold cross-validation was applied.

RESULTS

The classification via regression model was chosen as the best model. Our model had a robust MCC (.93, 95% CI .87-1.00, vs .64, 95% CI .57-.71) and specificity (100%, 95% CI 100-100, vs 90%, 95% CI 90-90) compared to each metric of the best models from recent studies. The sensitivity of this model was not inferior (95%, 95% CI 91-100, vs 100%, 95% CI 92-100). The area under the receiver operating characteristic curve was also competitive (0.970, 95% CI 0.966-0.974, vs 0.987, 95% CI 0.980-0.994). Features in the best model were maternal weight, BMI, pulsatility index of the UtA, sFlt-1, and PlGF. The most important feature was the sFlt-1/PlGF ratio. This model used an M5P algorithm consisting of a decision tree and four linear models with different thresholds. Our study was also better than the best ones among recent studies in terms of the class balance and the size of the case class (66/95, 69%, vs 27/239, 11.3%).

CONCLUSIONS

Our model had a robust predictive performance. It was also developed to deal with the problem of a class imbalance. In the context of clinical management, this model may improve maternal mortality and neonatal morbidity and reduce health care costs.

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.

Correlation of Kryptor and Elecsys® immunoassay sFlt-1/PlGF ratio on early diagnosis of preeclampsia and fetal growth restriction: A case-control study

OBJECTIVES

The measurement of the soluble fms-like tyrosine kinase-1 to placental growth factor (sFlt-1/PlGF) ratio on automated platforms has improved the detection of preeclampsia and fetal growth restriction (PE/FGR). The cut-off points of >38 and ≥85 has been defined for "rule in" and "aid in diagnosis", respectively, using the Elecsys® platform. We aimed to compare the performance of these cut-offs between the Elecsys® and Kryptor platforms at 24-28 weeks.

STUDY DESIGN

Observational case-control study of singleton pregnancies at high risk for PE/FGR and sFlt-1/PlGF measurement at 24-28 weeks' gestation: 21 cases (9 early PE/FGR with delivery <32 weeks) were 1:1 matched for body mass index and parity with 21 controls. Correlations of the sFlt-1, PlGF and sFlt-1/PlGF values and diagnostic accuracy of the >38 and ≥85 cutoffs for early and late PE/FGR using Elecsys® and Kryptor assays were evaluated.

MAIN OUTCOME MEASURES

PE/FGR cases showed significantly higher median (IQR) sFlt-1/PlGF values at 24-28 weeks vs. controls, using both Elecsys® and Kryptor platforms: 55 (13-254) and 97 (13-530) vs. 4.1 (2.0-6.5) and 3.9 (1.8-7.7), respectively. The sFlt-1/PlGF correlation between both methods was excellent (r² = 0.95) although lower PlGF and higher sFlt-1/PlGF values were observed with Kryptor. The higher diagnostic accuracy was obtained for early PE/FGR with the ≥85 cutoff (95.2%; 95%CI: 83.8-99.4%) in both platforms.

CONCLUSION

sFlt-1/PlGF measurements correlates well between Elecsys® and Kryptor platforms, and the cutoffs of >38 and ≥85 exhibit high diagnostic accuracy for assessing early PE/FGR at 24-28 weeks with both methods.

Combining Biomarkers to Predict Pregnancy Complications and Redefine Preeclampsia: The Angiogenic-Placental Syndrome

Placental dysfunction underlies a spectrum of perinatal pathologies, including preeclampsia and fetal growth restriction. Angiogenesis-related factors, including sFlt-1 (soluble fms-like tyrosine kinase 1) and PlGF (placental growth factor), play an important role in placental dysfunction; altered levels are detectable several weeks before onset of pregnancy complications. In vitro diagnostic tests for these biomarkers can improve early diagnosis and facilitate prediction of maternal and fetal outcomes. We assessed evidence for combining angiogenic biomarkers with other biomarkers or clinical parameters to predict maternal/fetal outcomes in pregnant women with placental dysfunction. Pooled information on placental perfusion (ultrasonography, mean arterial pressure), clinical characteristics, and biomarker levels (PlGF) can improve first-trimester prediction and preeclampsia diagnosis. Angiogenic factors (sFlt-1/PlGF ratio; PlGF alone) with or without clinical characteristics can facilitate second-/third-trimester prediction of early-onset and late-onset preeclampsia. A combination of increased sFlt-1/PlGF ratio and ultrasound can rule out early fetal growth restriction. The sFlt-1/PlGF ratio is also a reliable tool for discriminating between pregnancy-related hypertensive disorders, including superimposed preeclampsia and gestational hypertension. Analysis of angiogenic factors with or without uterine Doppler substantially improves sensitivity and specificity for predicting adverse outcomes and iatrogenic preterm delivery. We propose to extend the American College of Obstetricians and Gynecologists definition of preeclampsia in the future to include the combination of new-onset hypertension and new-onset of altered angiogenic factors (sFlt-1/PlGF ratio or PlGF alone). In summary, altered angiogenic biomarkers indicate placental dysfunction, and their implementation into clinical practice will help reduce the considerable burden of morbidity and mortality associated with adverse pregnancy outcomes as a consequence of angiogenic-placental syndrome.

Mechanisms of Endothelial Dysfunction in Pre-eclampsia and Gestational Diabetes Mellitus: Windows Into Future Cardiometabolic Health?

Placental insufficiency and adipose tissue dysregulation are postulated to play key roles in the pathophysiology of both pre-eclampsia (PE) and gestational diabetes mellitus (GDM). A dysfunctional release of deleterious signaling motifs can offset an increase in circulating oxidative stressors, pro-inflammatory factors and various cytokines. It has been previously postulated that endothelial dysfunction, instigated by signaling from endocrine organs such as the placenta and adipose tissue, may be a key mediator of the vasculopathy that is evident in both adverse obstetric complications. These signaling pathways also have significant effects on long term maternal cardiometabolic health outcomes, specifically cardiovascular disease, hypertension, and type II diabetes. Recent studies have noted that both PE and GDM are strongly associated with lower maternal flow-mediated dilation, however the exact pathways which link endothelial dysfunction to clinical outcomes in these complications remains in question. The current diagnostic regimen for both PE and GDM lacks specificity and consistency in relation to clinical guidelines. Furthermore, current therapeutic options rely largely on clinical symptom control such as antihypertensives and insulin therapy, rather than that of early intervention or prophylaxis. A better understanding of the pathogenic origin of these obstetric complications will allow for more targeted therapeutic interventions. In this review we will explore the complex signaling relationship between the placenta and adipose tissue in PE and GDM and investigate how these intricate pathways affect maternal endothelial function and, hence, play a role in acute pathophysiology and the development of future chronic maternal health outcomes.

Intraplacental Villous Artery Doppler as an Independent Predictor for Placenta-Mediated Disease and Its Comparison with Uterine Artery Doppler and/or Placental Biochemical Markers in Predictive Models: A Prospective Cohort Study

OBJECTIVES

To validate intraplacental villous artery (IPVA) Doppler as a predictor for placenta-mediated diseases (PMDs), to compare its predictive value with uterine artery (UtA) Doppler and placental biochemical markers, and to assess its value in predictive PMD models.

METHODS

IPVA and UtA indices (pulsatility index [PI] and resistance index [RI]) were recorded at 18-24 weeks of gestation in a cohort of 117 women. The predictive values of IPVA, UtA, and placental biochemical markers were analyzed and compared between the PMD group (the women who developed preeclampsia or intrauterine growth restriction) and the non-PMD group (the women who remained healthy throughout pregnancy and 3 months postpartum) using the receiver-operating characteristic curves. Logistic regression was used to compare predictive models for PMDs based on IPVA, UtA, and/or biochemical markers.

RESULTS

31 (26.5%) women developed PMD (17 preeclampsia and 14 intrauterine growth restriction). IPVA PI was significantly higher in the PMD group than in the non-PMD group (p = 0.001). UtA PI and RI values remained nonsignificant between both groups (p = 0.066 and 0.104, respectively). IPVA PI from the 3 main branches of the placenta, and specifically the central main stem villi, showed a strong association with PMDs in comparison to UtA (p = 0.03 and 0.001 vs. 0.29). Model prediction including IPVA and UtA PI with or without placental biomarkers did not add any further significance to IPVA PI alone (p = 0.03, 0.41, and 0.36).

CONCLUSIONS

IPVA PI appears superior to UtA PI or RI and placental biomarkers in PMD prediction. Model prediction for PMDs including IPVA, UtA Doppler, and biochemical markers did not enhance prediction values compared to IPVA Doppler alone.

sFlt-1/PlGF Ratio as a Predictive Marker in Women with Suspected Preeclampsia: An Economic Evaluation from a Swiss Perspective

In Switzerland, 2.3% of pregnant women develop preeclampsia. Quantification of the soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) ratio has shown a diagnostic value in the second and third trimesters of pregnancy, in particular in ruling out preeclampsia within one week. We estimated the economic impact of implementing sFlt-1/PlGF ratio evaluation, in addition to the standard of care (SOC), for women with suspected preeclampsia from a Swiss healthcare system's perspective. A decision tree model was developed to estimate direct medical costs of diagnosis and management of a simulated cohort of Swiss pregnant women with suspected preeclampsia (median week of gestation: 32) until delivery. The model compared SOC vs. SOC plus sFlt-1/PlGF ratio, using clinical inputs from a large multicenter study (PROGNOSIS). Resource use data and unit costs were obtained from hospital records and public sources. The assumed cost for sFlt-1/PlGF evaluation was €141. Input parameters were validated by clinical experts in Switzerland. The model utilized a simulated cohort of 6084 pregnant women with suspected preeclampsia (representing 7% of all births in Switzerland in 2015, n = 86,919). In a SOC scenario, 36% of women were hospitalized, of whom 27% developed preeclampsia and remained hospitalized until birth. In a sFlt-1/PlGF test scenario, 76% of women had a sFlt-1/PlGF ratio of ≤38 (2% hospitalized), 11% had a sFlt-1/PlGF ratio of >38-<85 (55% hospitalized), and 13% had a sFlt-1/PlGF ratio of ≥85 (65% hospitalized). Total average costs/pregnant woman (including birth) were €10,925 vs. €10,579 (sFlt-1/PlGF), and total costs were €66,469,362 vs. €64,363,060 (sFlt-1/PlGF). Implementation of sFlt-1/PlGF evaluation would potentially achieve annual savings of €2,105,064 (€346/patient), mainly due to reduction in unnecessary hospitalization. sFlt-1/PlGF evaluation appears economically promising in predicting short-term absence of preeclampsia in Swiss practice. Improved diagnostic accuracy and reduction in unnecessary hospitalization could lead to significant cost savings in the Swiss healthcare system.

Pre-eclampsia: pathophysiology and clinical implications

Pre-eclampsia is a common disorder that particularly affects first pregnancies. The clinical presentation is highly variable but hypertension and proteinuria are usually seen. These systemic signs arise from soluble factors released from the placenta as a result of a response to stress of syncytiotrophoblast. There are two sub-types: early and late onset pre-eclampsia, with others almost certainly yet to be identified. Early onset pre-eclampsia arises owing to defective placentation, whilst late onset pre-eclampsia may center around interactions between normal senescence of the placenta and a maternal genetic predisposition to cardiovascular and metabolic disease. The causes, placental and maternal, vary among individuals. Recent research has focused on placental-uterine interactions in early pregnancy. The aim now is to translate these findings into new ways to predict, prevent, and treat pre-eclampsia.

Management of pregnancy blood pressure increase in the emergency room: role of PlGF-based biochemical markers and relative economic impact

INTRODUCTION

To evaluate the clinical and economic impact of healthcare management of pregnant women with blood pressure increase (BPI) accessing emergency room (ER) and the utility of the introduction of a PlGF-based test in clinical practice.

MATERIALS AND METHODS

This retrospective cohort study included women with single pregnancies who performed at least 1 ER access for BPI after the 20th gestational week in 2016. BPI was subsequently classified as significant if associated with preeclampsia (PE) or Fetal Growth Restriction (FGR) and not significant otherwise. Two experts evaluated potential changes in patients' management with the introduction of a PlGF-based test. The direct healthcare cost was estimated.

RESULTS

We enrolled 107 patients, of which 30% showed significant BPI (17 PE cases, 13 FGR, and 2 both pathologies). Anamnestic, clinical, and laboratory evaluations were not effective in differentiating between significant and not significant BPI (p-values: .8320, .2856, and .2297, respectively). The introduction of a PlGF-based test would have reduced overtreatment and undertreatment. The test would have avoided 18% of all hospitalizations, 35% of hospitalizations for BPI, 43% of outpatient referrals, and 13% of ER accesses. The number of avoidable accesses was higher in women with not significant BPI. Overall, the mean total cost (from first ER access until delivery) was €2634 per woman and €401 would have been avoidable.

CONCLUSION

The clinical integration of PlGF-based tests is advantageous in diagnostic, prognostic and economic terms, as an objective marker of placental dysfunction.

The prediction of early preeclampsia: Results from a longitudinal proteomics study

OBJECTIVES

To identify maternal plasma protein markers for early preeclampsia (delivery <34 weeks of gestation) and to determine whether the prediction performance is affected by disease severity and presence of placental lesions consistent with maternal vascular malperfusion (MVM) among cases.

STUDY DESIGN

This longitudinal case-control study included 90 patients with a normal pregnancy and 33 patients with early preeclampsia. Two to six maternal plasma samples were collected throughout gestation from each woman. The abundance of 1,125 proteins was measured using high-affinity aptamer-based proteomic assays, and data were modeled using linear mixed-effects models. After data transformation into multiples of the mean values for gestational age, parsimonious linear discriminant analysis risk models were fit for each gestational-age interval (8-16, 16.1-22, 22.1-28, 28.1-32 weeks). Proteomic profiles of early preeclampsia cases were also compared to those of a combined set of controls and late preeclampsia cases (n = 76) reported previously. Prediction performance was estimated via bootstrap.

RESULTS

We found that 1) multi-protein models at 16.1-22 weeks of gestation predicted early preeclampsia with a sensitivity of 71% at a false-positive rate (FPR) of 10%. High abundance of matrix metalloproteinase-7 and glycoprotein IIbIIIa complex were the most reliable predictors at this gestational age; 2) at 22.1-28 weeks of gestation, lower abundance of placental growth factor (PlGF) and vascular endothelial growth factor A, isoform 121 (VEGF-121), as well as elevated sialic acid binding immunoglobulin-like lectin 6 (siglec-6) and activin-A, were the best predictors of the subsequent development of early preeclampsia (81% sensitivity, FPR = 10%); 3) at 28.1-32 weeks of gestation, the sensitivity of multi-protein models was 85% (FPR = 10%) with the best predictors being activated leukocyte cell adhesion molecule, siglec-6, and VEGF-121; 4) the increase in siglec-6, activin-A, and VEGF-121 at 22.1-28 weeks of gestation differentiated women who subsequently developed early preeclampsia from those who had a normal pregnancy or developed late preeclampsia (sensitivity 77%, FPR = 10%); 5) the sensitivity of risk models was higher for early preeclampsia with placental MVM lesions than for the entire early preeclampsia group (90% versus 71% at 16.1-22 weeks; 87% versus 81% at 22.1-28 weeks; and 90% versus 85% at 28.1-32 weeks, all FPR = 10%); and 6) the sensitivity of prediction models was higher for severe early preeclampsia than for the entire early preeclampsia group (84% versus 71% at 16.1-22 weeks).

CONCLUSION

We have presented herein a catalogue of proteome changes in maternal plasma proteome that precede the diagnosis of preeclampsia and can distinguish among early and late phenotypes. The sensitivity of maternal plasma protein models for early preeclampsia is higher in women with underlying vascular placental disease and in those with a severe phenotype.

Midpregnancy prediction of pre-eclampsia using serum biomarkers sFlt-1 and PlGF

OBJECTIVES

Pre-eclampsia remains a significant cause of morbidity and mortality. Placental biomarkers soluble Fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) have been investigated previously for their ability to predict pre-eclampsia. We compared the performance of these biomarkers for midpregnancy pre-eclampsia prediction using three different immunoassay platforms.

STUDY DESIGN

Prospective study including singleton pregnancies 19-22 weeks' gestation. Maternal bloods were collected at recruitment. Screening performances using receiver operating characteristic (ROC) curves for PlGF and sFlt-1/PlGF ratio raw data and MoM values in isolation were evaluated for three immunoassay platforms using selected cut-off values.

MAIN OUTCOME MEASURES

Pre-eclampsia was defined as early-onset (<34 weeks' at delivery) and preterm (<37 weeks' at delivery).

RESULTS

For prediction of preterm pre-eclampsia, PlGF MoM and sFlt-1/PlGF ratio MoM performed similarly, with areas under the curve (AUC), detection rates (DR) and false positive rates (FPR) for PlGF MoM and sFlt-1/PlGF ratio MoM being 0.77-0.79 and 0.71-0.74, 62.5% for both and 9.7-14.9 and 10.7-17.7, respectively. For the prediction of early-onset pre-eclampsia, sFlt-1/PlGF ratio raw data and MoM values performed similarly, with AUC, DR and FPR being 0.92-0.97 and 0.93-0.96, 100% for both, and 4.13-16.9 and 9.4-12.2, respectively.

CONCLUSIONS

For midpregnancy prediction of preterm pre-eclampsia, PlGF MoM for all three platforms and sFlt-1/PlGF ratio MoM for the two platforms that tested sFlt-1 performed similarly. For midpregnancy prediction of early-onset pre-eclampsia at midpregnancy, sFlt-1/PlGF ratio raw data and MoM values using the early-onset cut-off for the two platforms that tested sFlt-1 gave similar performance from a clinical perspective.

Diagnostic Accuracy of Different Soluble fms-Like Tyrosine Kinase 1 and Placental Growth Factor Cut-Off Values in the Assessment of Preterm and Term Preeclampsia: A Gestational Age Matched Case-Control Study

Introduction: The objective was to investigate the diagnostic accuracy of different thresholds of the soluble vascular endothelial growth factor receptor-1 (sFlt-1) and the placental growth factor (PlGF) in preterm (≤37 weeks) and term (>37 weeks) preeclampsia (PE). Materials and Methods: A nested case-control study was performed from a high-risk Swiss cohort. Only blood samples on the day of PE diagnosis were included. The primary outcome was to verify the diagnosis using the recently proposed cut-off values for PE (sFlt-1:PlGF ratio of ≥85 in ≤ 34 weeks or ≥110 in >34 weeks), and the gestational age dependent centiles. Results: Thirty-four women with preterm PE were matched with 64 controls and 25 women with term PE with 45 controls. The test performance of the sFlt-1:PlGF ratio in preterm PE was very good (AUROCC of 0.95). The sFlt-1:PlGF ratio could adequately predict adverse fetal or neonatal outcome. In term PE, sFlt-1 alone showed a slightly better diagnostic accuracy with an AUROCC of 0.84. Almost all women with a sFlt-1:PlGF ratio above threshold delivered during the following week. Discussion: In pregnant women with high risk of developing PE, the sFlt-1:PlGF ratio and sFlt-1 levels help clinicians to confirm the diagnosis of imminent preterm PE and can additionally be used to rule out PE at term.

ELABELA plasma concentrations are increased in women with late-onset preeclampsia

Objective: ELABELA is a newly discovered peptide hormone that appears to be implicated in the mechanisms leading to preeclampsia, independently of angiogenic factors. The aim of the current study was to investigate whether women with early- or late-onset preeclampsia have altered ELABELA plasma concentrations compared to gestational-age-matched normal pregnant women.Methods: This retrospective cross-sectional study focused on the maternal plasma samples collected from 232 women with a singleton pregnancy who were allocated into the following groups: (1) early-onset preeclampsia (<34 weeks of gestation, N = 56); (2) late-onset preeclampsia (≥34 weeks of gestation, N = 57); and (3) gestational-age-matched controls with a normal pregnancy [(<34 weeks of gestation, N = 59); (≥34 weeks of gestation, N = 60)]. ELABELA plasma concentrations were determined using a validated enzyme immunoassay.Results: (1) ELABELA plasma concentrations are higher in patients with late-onset preeclampsia compared with those from gestational-age-matched controls with a normal pregnancy [median: 7.99 ng/mL (IQR, 5.3-13.95 ng/mL) versus median: 4.17 ng/mL (IQR, 3-11.19 ng/mL), p =.001]; (2) ELABELA plasma concentrations in patients with early-onset preeclampsia do not differ from those of normal pregnant women [median: 6.09 ng/mL (IQR, 2.8-10.66 ng/mL) versus median: 4.02 ng/mL (IQR, 3.26-7.49), p = .32]; and (3) ELABELA plasma concentrations are higher in patients with late-onset preeclampsia compared to those with early-onset preeclampsia [median: 7.99 ng/mL (IQR, 5.3-13.95 ng/mL) versus median: 6.09 ng/mL (IQR, 2.8-10.66 ng/mL), p = .01].Conclusion: ELABELA plasma concentrations are higher in patients with late-onset preeclampsia than in those with a normal pregnancy. However, women with early-onset preeclampsia have similar ELABELA plasma concentrations to those with a normal pregnancy. These findings provide insight into the ELABELA axis during the human syndrome of preeclampsia. In addition, these data support the concept that different pathophysiologic mechanisms are implicated in early- and late-onset preeclampsia.

Evaluation of sFlt-1/PlGF Ratio for Predicting and Improving Clinical Management of Pre-eclampsia: Experience in a Specialized Perinatal Care Center

Background

Management of pregnant women at high risk of pre-eclampsia (PE) requires frequent monitoring, with referral to specialized perinatal care centers. Reliable tests are necessary to improve prediction of PE and related complications and to assess disease severity and progression. An imbalance in two biomarkers, soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF), is involved in PE pathogenesis. The sFlt-1 to PlGF ratio is increased in pregnant women before the onset of PE. An elevated ratio is highly predictive of PE, whereas the diagnosis of PE can be ruled out within one week for low ratios. The main objective of this study was to assess whether a low sFlt-1/PlGF ratio, below a cutoff of 38, can predict the absence of PE within one week.

Methods

We performed a prospective, monocentric, observational study to evaluate serum sFlt-1/PlGF ratio (Roche Diagnostics Cobas e411 system) for predicting -PE in a group of 67 high-risk pregnant women (20–37 gestation weeks).

Results

Among the 67 patients included, 53 had a sFlt-1/PlGF ratio lower than 38; none developed subsequent PE leading to a negative predictive value of 100%. Eight patients developed clinical PE. The positive predictive value was 21% at one week and 18% at four weeks, in accordance with previous studies.

Conclusions

The serum sFlt-1/PlGF ratio showed highly predictive performances for ruling out PE. Using these biomarkers in routine management of PE may improve clinical care and avoid inappropriate hospitalization, which has a significant economic impact.

Soluble fms-like tyrosine kinase-1 and placental growth factor kinetics during and after pregnancy in women with suspected or confirmed pre-eclampsia

OBJECTIVES

To assess the evolution of the soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) ratio in women with suspected or confirmed pre-eclampsia (PE), and to investigate the changes in sFlt-1 and PlGF levels in pre-eclamptic women after delivery.

METHODS

This was an exploratory study in which secondary analysis was performed on a prospective cohort study that enrolled women with a singleton pregnancy and suspected or confirmed PE from 18 weeks' gestation, carried out between December 2013 and April 2016 at the Department of Obstetrics of the Erasmus Medical Center in Rotterdam. sFlt-1 and PlGF were determined using Roche Diagnostics Elecsys assays in two groups of patients. In the first group, patients with suspected or confirmed PE had sFlt-1 and PlGF levels measured at least twice during their pregnancy. Changes in these biomarkers over the course of pregnancy were compared for patients in this group with a baseline sFlt-1/PlGF ratio of ≤ 38 and for those with a ratio > 38. In the second group, sFlt-1 and PlGF levels of women with PE or HELLP syndrome were measured before and after delivery. For this group, pre- and postpartum sFlt-1 and PlGF levels were compared and half-lives were calculated.

RESULTS

Women with suspected or confirmed PE for whom sFlt-1 and PlGF levels were measured at least twice during pregnancy (n = 46) had a median gestational age at inclusion of 26 weeks (range, 18-40 weeks). In 27 of the 30 patients with sFlt-1/PlGF ratio ≤ 38 at baseline, thereby ruling out PE, the sFlt-1/PlGF ratio remained stable for up to 100 days. In the remaining three patients with a ratio ≤ 38 and in most of the 16 patients with a ratio > 38, the ratio increased further. For women diagnosed with PE or HELLP syndrome for whom sFlt-1 and PlGF levels were measured before and after delivery (n = 26), median gestational age at inclusion was 29 weeks (range, 16-37 weeks) and median time between antepartum measurement and delivery was 2 days (range, 1-17 days). In this group, after delivery, sFlt-1 dropped to < 1% of its pre-delivery value, with a half-life of 1.4 ± 0.3 days, while PlGF dropped to ∼30% of its pre-delivery value, with a half-life of 3.7 ± 4.3 days.

CONCLUSIONS

Based on this small cohort, up to 10% of pregnant women admitted with suspected or confirmed PE presenting with a sFlt-1/PlGF ratio of ≤ 38 display a rise in sFlt-1/PlGF ratio in subsequent weeks, implying that repeat determination of the sFlt-1/PlGF ratio is required to exclude definitively a diagnosis of PE. Furthermore, the rapid and pronounced decline in sFlt-1 levels after delivery in patients with PE/HELLP syndrome suggests that sFlt-1, in contrast to PlGF, is almost entirely derived from the placenta. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Ophthalmic artery Doppler for prediction of pre-eclampsia: systematic review and meta-analysis

OBJECTIVE

To determine the accuracy of ophthalmic artery Doppler in pregnancy for the prediction of pre-eclampsia (PE).

METHODS

MEDLINE, EMBASE, CINAHL and The Cochrane Library were searched for relevant citations without language restrictions. Two reviewers independently selected studies that evaluated the accuracy of ophthalmic artery Doppler to predict the development of PE and extracted data to construct 2 × 2 tables. Individual patient data were obtained from the authors if available. A bivariate random-effects model was used for the quantitative synthesis of data. Logistic regression analysis was employed to generate receiver-operating characteristics (ROC) curves and obtain optimal cut-offs for each investigated parameter, and a bivariate analysis was employed using predetermined cut-offs to obtain sensitivity and specificity values and generate summary ROC curves.

RESULTS

A total of 87 citations matched the search criteria of which three studies, involving 1119 pregnancies, were included in the analysis. All included studies had clear description of the index and reference tests, avoidance of verification bias and adequate follow-up. Individual patient data were obtained for all three included studies. First diastolic peak velocity of ophthalmic artery Doppler at a cut-off of 23.3 cm/s showed modest sensitivity (61.0%; 95% CI, 44.2-76.1%) and specificity (73.2%; 95% CI, 66.9-78.7%) for the prediction of early-onset PE (area under the ROC curve (AUC), 0.68; 95% CI, 0.61-0.76). The first diastolic peak velocity had a much lower sensitivity (39.0%; 95% CI, 20.6-61.0%), a similar specificity (73.2%; 95% CI, 66.9-78.7%) and a lower AUC (0.58; CI, 0.52-0.65) for the prediction of late-onset PE. The pulsatility index of the ophthalmic artery did not show a clinically useful sensitivity or specificity at any cut-off for early- or late-onset PE. Peak ratio above 0.65 showed a similar diagnostic accuracy to that of the first diastolic peak velocity with an AUC of 0.67 (95% CI, 0.58-0.77) for early-onset PE and 0.57 (95% CI, 0.51-0.63) for late-onset disease.

CONCLUSIONS

Ophthalmic artery Doppler is a simple, accurate and objective technique with a standalone predictive value for the development of early-onset PE equivalent to that of uterine artery Doppler evaluation. The relationship between ophthalmic Doppler indices and PE cannot be a consequence of trophoblast invasion and may be related to maternal hemodynamic adaptation to pregnancy. The findings of this review justify efforts to elucidate the effectiveness and underlying mechanism whereby two seemingly unrelated maternal vessels can be used for the prediction of a disease considered a 'placental disorder'. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.