Prediction of pre-eclampsia by uterine artery Doppler ultrasonography and maternal serum pregnancy-associated plasma protein-A, free beta-human chorionic gonadotropin, activin A and inhibin A at 22 + 0 to 24 + 6 weeks' gestation

Placental elastography in second trimester preeclampsia prediction: A prospective study

OBJECTIVE

The aim of the study was to evaluate the diagnostic potential of placental shear wave elastography in predicting preeclampsia at 16 to 20 weeks of gestation.

MATERIALS AND METHODS

A total of 230 pregnant women between 16 and 20 weeks of gestation were observed for the study. These women underwent shear wave elastography ElastPQ (Philips Healthcare, Bothell, Washington, USA) of the placenta. The mean value of placental shear modulus was obtained for each participant. These participants were followed up for the development of preeclampsia and were divided into two groups; group A included those who developed preeclampsia and group B included those who remained normotensive until delivery. The elasticity values of the two groups were compared, and the ROC curve was drawn to obtain the best cut-off value that would predict the onset of preeclampsia.

RESULTS

Placental shear modulus varied from 1.03 kPa to 7.4 kPa at 16 to 20 weeks of gestation with an average of 2.74 ± 0.87 kPa. There was a statistically significant difference in the mean value of elasticity between two groups, being 4.61 kPa in group A and 2.51 kPa in group B. Maximum diagnostic accuracy was obtained at 2.9667 kPa with area under the curve 0.970, sensitivity 92%, specificity 91.71%, positive predictive value 57.5% and negative predictive value 98.9%.

CONCLUSION

Stiffness of placenta, quantitatively measured by SWE at 16 to 20 weeks of gestation, is higher in the women who develop preeclampsia and hence may be used for predicting preeclampsia.

Sustained Elevated Circulating Activin A Impairs Global Longitudinal Strain in Pregnant Rats: A Potential Mechanism for Preeclampsia-Related Cardiac Dysfunction

Mediators of cardiac injury in preeclampsia are not well understood. Preeclamptic women have decreased cardiac global longitudinal strain (GLS), a sensitive measure of systolic function that indicates fibrosis and tissue injury. GLS is worse in preeclampsia compared to gestational hypertension, despite comparable blood pressure, suggesting that placental factors may be involved. We previously showed that Activin A, a pro-fibrotic factor produced in excess by the placenta in preeclampsia, predicts impaired GLS postpartum. Here, we hypothesized that chronic excess levels of Activin A during pregnancy induces cardiac dysfunction. Rats were assigned to sham or activin A infusion (1.25–6 µg/day) on a gestational day (GD) 14 (n = 6–10/group). All animals underwent blood pressure measurement and comprehensive echocardiography followed by euthanasia and the collection of tissue samples on GD 19. Increased circulating activin A (sham: 0.59 ± 0.05 ng/mL, 6 µg/day: 2.8 ± 0.41 ng/mL, p < 0.01) was associated with impaired GLS (Sham: −22.1 ± 0.8%, 6 µg/day: −14.7 ± 1.14%, p < 0.01). Activin A infusion (6 µg/day) increased beta-myosin heavy chain expression in heart tissue, indicating cardiac injury. In summary, our findings indicate that increasing levels of activin A during pregnancy induces cardiac dysfunction and supports the concept that activin A may serve as a possible mediator of PE-induced cardiac dysfunction.

Uterine artery Doppler for the prediction of outcome in pregnancies complicated by hypertensive disorders of pregnancy

OBJECTIVES

To evaluate, in pregnancies complicated by hypertensive disorders of pregnancy (HDP), the predictive role of uterine artery (UtA) Doppler for pregnancy outcome compared to the definition of preeclampsia (PE) established by ISSHP recommendations.

STUDY DESIGN

Retrospective cohort study including singleton pregnancies diagnosed with HDP, who underwent UtA Doppler assessment at admission in 2011-2017. The study population was classified considering the presence or absence of PE and according to the presence or absence of abnormal UtA Doppler (mean pulsatility index > 95th percentile).

MAIN OUTCOME MEASURES

Pregnancy outcome, maternal and fetal complications, evaluated as composite outcomes (CO), and duration of pregnancy (from admission to delivery).

RESULTS

A total of 311 mother-infant couples was included.The diagnostic ability of the two classifications was analysed comparing the relative likelihood ratio in the Biggerstaff graph. ISSHP definition turned out to be more efficient in detecting maternal adverse CO in comparison to UtA Doppler, relative positive likelihood ratio 1.50 (1.35-1.66) and 1.31 (1.07-1.60). UtA Doppler classification resulted more efficient in predicting adverse neonatal CO than PE definition, relative positive likelihood ratio 2.21 (1.77-2.75) and 1.61 (1.37-1.90). UtA Doppler was significantly associated with delivery at earlier gestational ages both for patients affected by PE and for women affected by HDP without superimposed PE (respectively p = 0.009 and p = 0.037).

CONCLUSIONS

UtA Doppler at HDP diagnosis is a useful bedside marker of fetal/neonatal complications, and is associated with pregnancy duration.

Predictive Performance of Serum β-hCG MoM Levels for Preeclampsia Screening: A Meta-Analysis

OBJECTIVE

The aim of the present study was to investigate the predictive value of using the multiple of the median (MoM) of β-human chorionic gonadotropin (β-hCG) levels in patients with preeclampsia (PE) and healthy pregnant women.

METHODS

Electronic databases including PubMed, EBSCO, Ovid, Web of Science, China National Knowledge Infrastructure (CNKI), SinoMed, Wangfang and the Weipu Journal were searched up to May 31, 2020. Two reviewers independently selected the articles and extracted data on study characteristics, quality and results. A random-effects model was employed, and standardized mean difference and 95% confidence intervals were calculated. Twenty-one case-control studies were analyzed in the present meta-analysis, including a total of 2,266 cases and 25,872 healthy controls.

RESULTS

Women who were diagnosed with PE were found to have higher early second-trimester levels of serum β-hCG MoM compared with healthy controls, although the levels in the first trimester were not significantly different. Ethnicity subgroup analysis demonstrated that the MoM of β-hCG serum levels was significantly higher in PE patients in both Asian and Caucasian populations during the early second trimester.

CONCLUSION

The MoM of β-hCG serum levels was found to be a valuable clinical indicator for predicting PE in the early second trimester, but had little predictive value in the first trimester. However, further assessment of the predictive capacity of β-hCG within larger, diverse populations is required.

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.

Integrated Systems Biology Approach Identifies Novel Maternal and Placental Pathways of Preeclampsia

Preeclampsia is a disease of the mother, fetus, and placenta, and the gaps in our understanding of the complex interactions among their respective disease pathways preclude successful treatment and prevention. The placenta has a key role in the pathogenesis of the terminal pathway characterized by exaggerated maternal systemic inflammation, generalized endothelial damage, hypertension, and proteinuria. This sine qua non of preeclampsia may be triggered by distinct underlying mechanisms that occur at early stages of pregnancy and induce different phenotypes. To gain insights into these molecular pathways, we employed a systems biology approach and integrated different "omics," clinical, placental, and functional data from patients with distinct phenotypes of preeclampsia. First trimester maternal blood proteomics uncovered an altered abundance of proteins of the renin-angiotensin and immune systems, complement, and coagulation cascades in patients with term or preterm preeclampsia. Moreover, first trimester maternal blood from preterm preeclamptic patients in vitro dysregulated trophoblastic gene expression. Placental transcriptomics of women with preterm preeclampsia identified distinct gene modules associated with maternal or fetal disease. Placental "virtual" liquid biopsy showed that the dysregulation of these disease gene modules originates during the first trimester. In vitro experiments on hub transcription factors of these gene modules demonstrated that DNA hypermethylation in the regulatory region of ZNF554 leads to gene down-regulation and impaired trophoblast invasion, while BCL6 and ARNT2 up-regulation sensitizes the trophoblast to ischemia, hallmarks of preterm preeclampsia. In summary, our data suggest that there are distinct maternal and placental disease pathways, and their interaction influences the clinical presentation of preeclampsia. The activation of maternal disease pathways can be detected in all phenotypes of preeclampsia earlier and upstream of placental dysfunction, not only downstream as described before, and distinct placental disease pathways are superimposed on these maternal pathways. This is a paradigm shift, which, in agreement with epidemiological studies, warrants for the central pathologic role of preexisting maternal diseases or perturbed maternal-fetal-placental immune interactions in preeclampsia. The description of these novel pathways in the "molecular phase" of preeclampsia and the identification of their hub molecules may enable timely molecular characterization of patients with distinct preeclampsia phenotypes.

High-throughput deep screening and identification of four peripheral leucocyte microRNAs as novel potential combination biomarkers for preeclampsia

OBJECTIVE

To identify the specific microRNA (miRNA) biomarkers of preeclampsia (PE), the miRNA profiles analysis were performed.

STUDY DESIGN

The blood samples were obtained from five PE patients and five normal healthy pregnant women. The small RNA profiles were analyzed to identify miRNA expression levels and find out miRNAs that may associate with PE. The quantitative reverse transcriptase-PCR (qRT-PCR) assay was used to validate differentially expressed peripheral leucocyte miRNAs in a new cohort.

RESULT

The data analysis showed that 10 peripheral leucocyte miRNAs were significantly differently expressed in severe PE patients. Four differently expressed miRNAs were successfully validated using qRT-PCR method.

CONCLUSION

We successfully constructed a model with high accuracy to predict PE. A combination of four peripheral leucocyte miRNAs has great potential to serve as diagnostic biomarkers of PE.

Apelin in Normal Pregnancy and Pregnancies Complicated by Placental Insufficiency

INTRODUCTION

Apelin is a potent inotropic agent and causes endothelium-mediated vasodilation. Its cardiovascular profile suggests a role in the regulation of gestational hemodynamics.

METHODS

We longitudinally assessed maternal serum apelin levels and hemodynamics (cardiac output and total peripheral resistance) between 20 and 34 weeks gestation in 18 women at high risk of placental dysfunction. Placental apelin staining was assessed by immunohistochemistry in placentas from uncomplicated pregnancies (n = 6), preterm deliveries (n = 6), preeclampsia (PET, n = 8), and isolated intrauterine growth restriction (IUGR, n = 8). Placental apelin gene expression was assessed by quantitative polymerase chain reaction.

RESULTS

In the high-risk cohort, 4 fetuses developed isolated IUGR and 6 women developed PET. We obtained a median of 5 (range 2-9) hemodynamic and apelin measurements per woman. Apelin levels throughout gestation were best fitted by a quadratic curve. Apelin levels between 20 and 26 weeks gestation correlated with total peripheral resistance (r = .57, P = .01) and showed a trend toward an inverse correlation with stroke volume (r = -.42, P = .08). Apelin serum levels were 30% lower in pregnancies complicated by IUGR than in uncomplicated pregnancies or in women with preeclampsia (P = .009). Placental apelin gene expression was similar in IUGR, PET, preterm, and term normal placentas. Apelin staining was seen both in syncytiotrophoblast and stroma of the placental villi. In IUGR placentas, apelin staining was strongly decreased in both compartments compared to normals. Preeclamptic placentas showed an intermediate staining.

CONCLUSIONS

Apelin levels mirror the cardiovascular changes seen in pregnancy. Serum and placental apelin levels are decreased in IUGR.

Evaluation of Serum Pregnancy Associated Plasma Protein-A & Plasma D-Dimer in Acute Coronary Syndrome

INTRODUCTION

Acute coronary syndrome (ACS), a spectrum comprising unstable angina pectoris, ST Elevated Myocardial Infarction (STEMI) & Non ST Elevated Myocardial Infarction (NSTEMI) is the major cause of presentation in Emergency Department today. Though ECG and cardiac enzymes are used for diagnosis, they mislead the diagnosis sometimes and delay in treatment initiation. This leads us to search certain new parameters which reflect the pathophysiology of ACS. Markers of plaque stability like Pregnancy Associated Plasma Protein-A and D-Dimer, a marker of ongoing thrombosis are found to be better markers in early diagnosis.

AIM

To evaluate the diagnostic competence of PAPP-A and D-Dimer in acute coronary syndrome over CK-MB and to compare with the inflammatory marker High Sensitive C-Reactive Protein (hs-CRP) which is associated with atherosclerosis.

MATERIALS AND METHODS

Fifty patients presenting with acute onset of chest pain to Emergency Department with or without ECG changes served as cases and 50 healthy people served as controls. Serum PAPP-A is measured by Enzyme Linked Immunosorbent Assay (ELISA), D-Dimer and hs-CRP by using Latex Turbidimetry method.

RESULTS

A statistical significant difference of PAPP-A and D-Dimer was noted between the ACS and controls (p < 0.001) whereas CK-MB shows no much difference (p 0.09). Statistically significant positive correlation is noted between parameters.

CONCLUSION

PAPP-A marker of plaque instability and D-Dimer marker of ongoing thrombosis are raised in acute coronary syndrome and thus can be considered as one of the marker in ACS for diagnosis.

Preeclampsia - What is to blame? The placenta, maternal cardiovascular system or both?

Preeclampsia (PE) is a pregnancy-specific syndrome, complicating 2%-8% of pregnancies. PE is a major cause of maternal mortality throughout the world with 60000 maternal deaths attributed to hypertensive disorders of pregnancy. PE also results in fetal morbidity due to prematurity and fetal growth restriction. The precise aetiology of PE remains an enigma with multiple theories including a combination of environmental, immunological and genetic factors. The conventional and leading hypotheses for the initial insult in PE is inadequate trophoblast invasion which is thought to result in incomplete remodelling of uterine spiral arteries leading to placental ischaemia, hypoxia and thus oxidative stress. The significant heterogeneity observed in pre-eclampsia cannot be solely explained by the placental model alone. Herein we critically evaluate the clinical (risk factors, placental blood flow and biomarkers) and pathological (genetic, molecular, histological) correlates for PE. Furthermore, we discuss the role played by the (dysfunctional) maternal cardiovascular system in the aetiology of PE. We review the evidence that demonstrates a role for both the placenta and the cardiovascular system in early- and late-onset PE and highlight some of the key differences between these two distinct disease entities.

Early prediction of hypertension during pregnancy in a low-resource setting

OBJECTIVE

To evaluate the role of maternal factors, biomarkers, and uterine-artery Doppler in the prediction of hypertension during pregnancy.

METHODS

A prospective cohort study was performed between December 2012 and November 2014. All singleton pregnancies between 11 weeks and 13 weeks, 6 days of pregnancy were included. Patients had their body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters), mean arterial pressure, uterine-artery Doppler pulsatility index, and pregnancy-associated plasma protein A (PAPP-A) and free β-human chorionic gonadotropin levels recorded. Any patients diagnosed with hypertension during follow-up were assigned to the case cohort; all other patients were assigned to the control group.

RESULTS

Hypertension during pregnancy was observed in 198 (9.7%) of 2042 patients that attended follow-up. The mean BMI, mean arterial pressure, uterine-artery Doppler pulsatility index, and the PAPP-A level at study enrollment were all significantly correlated with the later development of hypertension (P<0.001 for all variables). The combined sensitivity, specificity, positive predictive value, and negative predictive value of using the investigated parameters to predict hypertension was 76%, 80%, 31%, and 93%, respectively.

CONCLUSION

Patient BMI, mean arterial pressure, PAPP-A, and pulsatility index were found to be effective predictors of hypertension during pregnancy. Combining these predictors may be beneficial in selecting individuals for close monitoring and early intervention during pregnancy.

Diagnosis and Treatment of Hypertensive Pregnancy Disorders. Guideline of DGGG (S1-Level, AWMF Registry No. 015/018, December 2013)

Purpose: Official guideline published and coordinated by the German Society of Gynecology and Obstetrics (DGGG). Hypertensive pregnancy disorders contribute significantly to perinatal as well as maternal morbidity and mortality worldwide. Also in Germany these diseases are a major course for hospitalization during pregnancy, iatrogenic preterm birth and long-term cardiovascular morbidity. Methods: This S1-guideline is the work of an interdisciplinary group of experts from a range of different professions who were commissioned by DGGG to carry out a systematic literature search of positioning injuries. Members of the participating scientific societies develop a consensus in an informal procedure. Afterwards the directorate of the scientific society approves the consensus. Recommendations: This guideline summarizes the state-of-art for classification, risk stratification, diagnostic, treatment of hypertensive pregnancy disorders.

Predictive Value of Free β-hCG Multiple of the Median for Women with Preeclampsia

BACKGROUND

Preeclampsia (PE) is relatively common and is unpredictable in its onset and progression.

AIMS

We investigated the clinical value of using the multiple of the median (MoM) of free β-human chorionic gonadotropin (β-hCG) concentrations in women with normal pregnancy and PE.

METHODS

This study was based on a dataset available from published studies, and the relevant studies were retrieved from multiple electronic databases. Data were extracted from case-control studies; a random-effects model was employed, and standardized mean difference and 95% confidence intervals were calculated. Twelve case-control studies (eleven English-based articles and one Chinese-based article) were analyzed in the current meta-analysis and included 702 patients with PE and 8,233 women with normal pregnancies.

RESULTS

Statistical analysis revealed a higher MoM of β-hCG serum levels in patients with PE. Ethnicity subgroup analysis showed that the MoM of serum β-hCG levels was significantly higher in women with PE in both Asian and Caucasian populations.

CONCLUSION

The MoM of β-hCG serum levels was significantly increased in women with PE compared to women with normal pregnancies. Screening for serum β-hCG MoM levels will be helpful in the early identification of pregnancies at risk of developing PE. © 2015 S. Karger AG, Basel.

Pulsatility index in combination with biomarkers or mean arterial pressure for the prediction of pre-eclampsia: Systematic literature review and meta-analysis

INTRODUCTION

Our objective was to perform a meta-analysis examining the sensitivity of pulsatility index (PI) and various biomarkers and PI and mean arterial pressure (MAP) for the prediction of pre-eclampsia.

MATERIAL AND METHODS

PubMed, CENTRAL, and Embase databases were searched from inception until 8 May 2014 using combinations of the search terms: pre-eclampsia, ultrasonography, pregnancy, biomarker, mean arterial pressure, placental protein 13, pregnancy-associated plasma protein-A, placental growth factor, activin A, inhibin A, pulsatility index. The pooled sensitivity of PI + biomarkers and PI + MAP were calculated, and reported with corresponding 95% confidence intervals (CIs).

RESULTS

Fifteen studies were included in the meta-analysis. The pooled sensitivity of all biomarkers for the prediction of pre-eclampsia was 0.669 (95% CI 0.610-0.723), for the prediction of early-onset pre-eclampsia was 0.830 (95% CI 0.794-0.861), and for the prediction of late-onset pre-eclampsia was 0.564 (95% CI 0.499-0.627). Similarly, the predictive ability of PI + MAP for early-onset pre-eclampsia was good (sensitivity 0.894), while that for late-onset was poor (sensitivity 0.570).

CONCLUSION

The combination of PI and different biomarkers or MAP exhibits a good predictive ability for early-onset pre-eclampsia, and poor predictive ability for late-onset pre-eclampsia.

Inhibin at 90: from discovery to clinical application, a historical review

When it was initially discovered in 1923, inhibin was characterized as a hypophysiotropic hormone that acts on pituitary cells to regulate pituitary hormone secretion. Ninety years later, what we know about inhibin stretches far beyond its well-established capacity to inhibit activin signaling and suppress pituitary FSH production. Inhibin is one of the major reproductive hormones involved in the regulation of folliculogenesis and steroidogenesis. Although the physiological role of inhibin as an activin antagonist in other organ systems is not as well defined as it is in the pituitary-gonadal axis, inhibin also modulates biological processes in other organs through paracrine, autocrine, and/or endocrine mechanisms. Inhibin and components of its signaling pathway are expressed in many organs. Diagnostically, inhibin is used for prenatal screening of Down syndrome as part of the quadruple test and as a biochemical marker in the assessment of ovarian reserve. In this review, we provide a comprehensive summary of our current understanding of the biological role of inhibin, its relationship with activin, its signaling mechanisms, and its potential value as a diagnostic marker for reproductive function and pregnancy-associated conditions.

Uterine artery Doppler, birth weight and timing of onset of pre-eclampsia: providing insights into the dual etiology of late-onset pre-eclampsia

OBJECTIVE

To investigate the relationship between uterine artery Doppler ultrasound indices and birth weight in women with early-, intermediate- and late-onset pre-eclampsia as compared with women with uneventful pregnancy outcome.

METHODS

In a retrospective, observational cohort study, uterine artery Doppler assessment was carried out at 18+0 to 23+6 weeks' gestation in 26,893 women attending for routine antenatal care in a tertiary care center. The mean resistance index (RI) and its relationship to the outcome of pregnancy and birth-weight centiles were evaluated.

RESULTS

Uterine artery RI showed a significant, negative correlation with birth weight (r= -0.20, P<0.0001). Patients with early-onset pre-eclampsia had an increased prevalence of high uterine artery mean RI, above the 90(th) centile, corresponding to an increased proportion of small-for-gestational age (SGA) neonates with a birth weight below the 10(th) centile. In late-onset pre-eclampsia, however, there was an unexpectedly higher proportion of large-for-gestational-age (LGA) neonates with a birth weight above the 90(th) centile without a concurrent increase in the prevalence of low uterine artery mean RI below the 10(th) centile.

CONCLUSIONS

The finding of a bimodal skewed distribution of birth weight, with neonates exhibiting a higher prevalence of both LGA and SGA with late-onset pre-eclampsia, indicates that there are two types of late-onset pre-eclampsia. These findings explain the poor performance of mid-trimester uterine artery Doppler in predicting pre-eclampsia at term and provide insights into the placental origins of the early and late forms of pre-eclampsia.

Pregnancy-associated plasma protein A (PAPP-A) and preeclampsia

Pregnancy-associated plasma protein A (PAPP-A) is a key regulator of insulin-like growth factor bioavailability essential for normal fetal development. In maternal blood, this protein increases with gestational age and then rapidly decreases after delivery. It is routinely used for Down syndrome screening in the first trimester of pregnancy, and its decrease compared to a normal pregnancy indicates an increased risk for both chromosomal anomalies and adverse pregnancy outcomes. It belongs to a group of biomarkers that predict later preeclampsia development, primarily early onset preeclampsia; however, it should be combined with a Doppler ultrasonography of the uterine artery (pulsatile index) and other biochemical and maternal factors to achieve a higher detection rate with an acceptable false positivity rate. Some studies have demonstrated an even more pronounced decrease of PAPP-A in the early second trimester of pregnancy in women who subsequently develop preeclampsia compared with women who do not develop preeclampsia. Conversely, during the last trimester of pregnancy, its concentration increases even more in patients with preeclampsia than in patients without. It is also detectable at very low levels in nonpregnant individuals, and a higher concentration indicates an adverse effect in patients with acute coronary syndromes or stable atherosclerotic disease and in patients with end-stage renal disease who are being treated with hemodialysis.

Clinical applications of biomarkers in preeclampsia

Preeclampsia remains a significant cause of maternal morbidity and mortality worldwide. Prediction, diagnosis and management continue to be challenging but advances in the understanding of the pathophysiological processes underlying the disease has enabled identification of multiple biomarkers, some of which aid prediction of those at risk. Even in isolation, some of these biomarkers have demonstrated sufficient test performance for incorporation into clinical practice. A combination of the most promising biomarkers and clinical factors may improve risk prediction, and aid diagnosis and subsequent management through development of integrated clinical risk models. This article aims to review the literature relating to biomarkers in preeclampsia and summarize the possible clinical applications of these findings.

Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy

OBJECTIVE

This guideline summarizes the quality of the evidence to date and provides a reasonable approach to the diagnosis, evaluation and treatment of the hypertensive disorders of pregnancy (HDP).

EVIDENCE

The literature reviewed included the previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines from 2008 and their reference lists, and an update from 2006. Medline, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Registry of Controlled Trials (CCRCT) and Database of Abstracts and Reviews of Effects (DARE) were searched for literature published between January 2006 and March 2012. Articles were restricted to those published in French or English. Recommendations were evaluated using the criteria of the Canadian Task Force on Preventive Health Care and GRADE.

The activins and their binding protein, follistatin-Diagnostic and therapeutic targets in inflammatory disease and fibrosis

The activins, as members of the transforming growth factor-β superfamily, are pleiotrophic regulators of cell development and function, including cells of the myeloid and lymphoid lineages. Clinical and animal studies have shown that activin levels increase in both acute and chronic inflammation, and are frequently indicators of disease severity. Moreover, inhibition of activin action can reduce inflammation, damage, fibrosis and morbidity/mortality in various disease models. Consequently, activin A and, more recently, activin B are emerging as important diagnostic tools and therapeutic targets in inflammatory and fibrotic diseases. Activin antagonists such as follistatin, an endogenous activin-binding protein, offer considerable promise as therapies in conditions as diverse as sepsis, liver fibrosis, acute lung injury, asthma, wound healing and ischaemia-reperfusion injury.

The obstetric syndromes: clinical relevance of placental hormones

Preterm delivery, preeclampsia and intrauterine growth restriction are the major diseases of pregnancy. A key role in their pathogenesis is played by the placenta, which is the source of hormones and other important regulatory molecules providing the metabolic and endocrine homeostasis of the fetal-placental unit. Since obstetric syndromes are characterized by important maternal and neonatal morbidity and mortality worldwide, numerous efforts have been made over the years to prevent and treat them. Due to their complex pathogenesis, however, the therapy is poor and not very effective. Therefore, great emphasis is currently given to the prevention of these diseases through the identification of biochemical and biophysical markers, among which placental factors play a crucial role. The increasing knowledge of the role of placental molecules can indeed lead to the development of new therapeutic and diagnostic tools.

Placental protein 13 (PP13): a new biological target shifting individualized risk assessment to personalized drug design combating pre-eclampsia

BACKGROUND

Pre-eclampsia affects 2-7% of all pregnant women and is a major cause of maternal and fetal morbidity and mortality. The etiology of pre-eclampsia is still unknown but it is well documented that impaired placentation is a major contributor to its development. One of the placenta-specific proteins is placental protein 13 (PP13). Lower first trimester levels of maternal serum PP13 and its encoding placental mRNA are associated with the development of both early and late-onset severe pre-eclampsia. In cases where this protein is mutated, the frequency of pre-eclampsia is higher.

METHODS

19 out of 68 studies on PP13, published between January 2006 and September 2012, were used to evaluate the value of maternal blood PP13 as a marker of pre-eclampsia.

RESULTS

A meta-analysis presented in this review shows that low serum levels of PP13 in the first trimester of pregnancy can predict the development of pre-eclampsia later in pregnancy. Although some functions of this protein have been assessed in in vitro experiments, the in vivo functions of PP13 are still unknown, especially when circulating in the maternal bloodstream. A recent pilot study has shown that in gravid rats PP13 causes significant vasodilatation, reduced blood pressure and increased maternal uterine artery remodeling.

CONCLUSION

Reviewing these effects of PP13, the authors propose the use of PP13 as a new drug candidate. Replenishing PP13 in those women with low serum levels early in pregnancy may help prepare their vasculature for pregnancy. This novel pharmacological approach to combat pre-eclampsia is presented as a new direction to transfer from individualized risk to personalized prevention.

Hypertensive disorders of pregnancy: preventative-, immediate- and long-term management

The hypertensive disorders of pregnancy are common and continue to be significant contributors to maternal and perinatal mortality and morbidity, both globally and in the UK. This review aims to describe the recent developments in the understanding of the pathophysiology of the disease processes, potential strategies for identification of women at high risk, and current and future therapeutic strategies for the treatment and prevention of hypertension in pregnancy. Women who experience adverse pregnancy outcomes are also at increased risk of premature cardiovascular disease, and potential therapeutic strategies to minimize their risk profile are discussed.

Preeclampsia: a bioinformatics approach through protein-protein interaction networks analysis

Background

In this study we explored preeclampsia through a bioinformatics approach. We create a comprehensive genes/proteins dataset by the analysis of both public proteomic data and text mining of public scientific literature. From this dataset the associated protein-protein interaction network has been obtained. Several indexes of centrality have been explored for hubs detection as well as the enrichment statistical analysis of metabolic pathway and disease.

Results

We confirmed the well known relationship between preeclampsia and cardiovascular diseases but also identified statistically significant relationships with respect to cancer and aging. Moreover, significant metabolic pathways such as apoptosis, cancer and cytokine-cytokine receptor interaction have also been identified by enrichment analysis. We obtained FLT1, VEGFA, FN1, F2 and PGF genes with the highest scores by hubs analysis; however, we also found other genes as PDIA3, LYN, SH2B2 and NDRG1 with high scores.

Conclusions

The applied methodology not only led to the identification of well known genes related to preeclampsia but also to propose new candidates poorly explored or completely unknown in the pathogenesis of preeclampsia, which eventually need to be validated experimentally. Moreover, new possible connections were detected between preeclampsia and other diseases that could open new areas of research. More must be done in this area to resolve the identification of unknown interactions of proteins/genes and also for a better integration of metabolic pathways and diseases.

The value of early second trimester PAPP-A and ADAM12 in screening for pre-eclampsia

OBJECTIVE

To estimate the pre-eclampsia screening performance of PAPP-A (pregnancy-associated plasma protein-A) and ADAM12 (A Disintegrin And Metalloprotease 12) in the early second trimester of pregnancy.

METHODS

Stored frozen serum samples from a previously published nested case-control study comprising 77 women who developed pre-eclampsia and 224 unaffected controls were thawed and assayed for PAPP-A and ADAM12. Levels were converted into multiple of the unaffected median (MoM) values.

RESULTS

Neither PAPP-A or ADAM12 were significantly different in women who developed pre-eclamspia compared with unaffected controls (PAPP-A: 0.97 MoM [95% confidence interval 0.73 to 1.25], ADAM12: 1.01 MoM [0.91 to 1.13]).

CONCLUSION

Our results do not support the use of PAPP-A or ADAM12 in early second trimester antenatal screening for pre-eclampsia.

Angiogenic growth factors in the diagnosis and prediction of pre-eclampsia

The pathogenesis of pre-eclampsia is still not completely known; however, in the recent decade, there have been tremendous research efforts leading to impressive results highlighting the role of a disturbed angiogenic balance as one of the key features of the disease. Numerous studies have shown the key role of the placenta in the pathogenesis of pre-eclampsia. A shift in the sFlt-1 (soluble Fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio is associated with the disease. Although pre-eclampsia seems to be a clearly defined disease, clinical presentation, and particularly the dynamics of the clinical course, can vary enormously. The only available tools to diagnose pre-eclampsia are blood pressure measurement and urine protein sampling. However, these tools have a low sensitivity and specificity regarding the prediction of the course of the disease or maternal and perinatal outcomes. The only cure for the disease is delivery, although a timely diagnosis helps in decreasing maternal and fetal morbidity and mortality. The sFlt1/PlGF ratio is able to give additional valuable information on the status and progression of the disease and is apt to be implemented in the diagnostic algorithm of pre-eclampsia. In the present review, we aim to provide an overview of the vast literature on angiogenesis and anti-angiogenesis factors in pre-eclampsia that have been published over the last decade. We introduce work from basic research groups who have focused on the pathophysiological basis of the disease. Furthermore, we review studies with a clinical focus in which the sFlt-1/PlGF ratio has been analysed along with other candidates for routine clinical assessment of pre-eclampsia.

Screening for pre-eclampsia: a systematic review of tests combining uterine artery Doppler with other markers

AIMS

To perform a systematic review of screening for pre-eclampsia (PE) with the combination of uterine artery Doppler (UAD), maternal history, mean arterial pressure and/or maternal serum markers.

METHODS

We identified eligible studies through a search of Medline, and, for each included study, we assessed the risk of bias and extracted relevant data. We reported the performance of screening tests according to the target population (low- or high-risk), the trimester of screening (first and/or second) and the subset of PE screened for (early and late).

RESULTS

Several tests provided moderate or convincing prediction of early PE, but screening for late PE was poor. Although UAD is more accurate in the second trimester, we found encouraging results for first-trimester screening when it was combined with other markers. Performance of screening was consistently lower in populations with risk factors for PE in the maternal history.

CONCLUSIONS

We present encouraging results for the prediction of early PE, even in the first trimester of pregnancy. The different performance of tests in screening for early vs. late PE, and of low- vs. high-risk populations, supports the concept that PE is a heterogeneous disease.

Uterine artery Doppler and adverse pregnancy outcome in women with extreme levels of fetoplacental proteins used for Down syndrome screening

OBJECTIVE

To evaluate the use of second-trimester uterine artery (UtA) Doppler to predict adverse pregnancy outcome in women with extreme levels of fetoplacental proteins used for Down syndrome screening.

METHODS

At a single institution, women screened for Down syndrome were offered second-trimester UtA Doppler examination if they had one of the following on analysis of maternal serum: pregnancy-associated plasma protein-A ≤ 0.28 multiples of the median (MoM) (1% of screened population), inhibin ≥ 3.0 MoM (2%), human chorionic gonadotropin ≥ 4.0 MoM (2%), alpha-fetoprotein (AFP) ≥ 2.5 MoM (2%), estriol ≤ 0.5 MoM (1%). Abnormal UtA Doppler was defined as bilateral or unilateral notching or mean pulsatility index ≥ 1.45.

RESULTS

Of 240 women studied, 92 (38.3%) had an adverse pregnancy outcome: small for gestational age (either < 10(th) customized centile (SGA(10) ) or < 5(th) customized centile (SGA(5) )), low birth weight (LBW, < 2.5 kg), preterm delivery (< 37 + 0 weeks of gestation), fetal loss (late miscarriage or stillbirth), placental abruption and gestational hypertension. Of 167 women screened with all five hormones, those with two or more extreme levels (n = 18, 10.8%) were significantly at risk of adverse pregnancy outcome compared with those with only one marker (61.1% vs. 35.6%, P = 0.04). UtA Doppler was abnormal in 20% (32 of 159 women screened) and increased the risk of adverse pregnancy outcome (RR 2.5, 65.6% vs. 26.0%, P < 0.001). SGA(10) , SGA(5) and LBW were significantly more common in women with abnormal UtA Doppler (RR 2.98, 56.2% vs. 18.9%, P < 0.001, RR 4.6, 43.7% vs. 9.4%, P < 0.001 and RR 4.4, 31.2% vs. 7.1%, P < 0.001, respectively). Women with normal Doppler examination still had a 26% risk of adverse pregnancy outcome.

CONCLUSIONS

In women with extreme levels of feto-placental proteins used for Down syndrome screening, an abnormal second-trimester UtA Doppler examination confers a high risk of adverse pregnancy outcome and SGA in particular, but a normal examination does not rule out an adverse pregnancy outcome.

Predicting the risk of pre-eclampsia between 11 and 13 weeks' gestation by combining maternal characteristics and serum analytes, PAPP-A and free β-hCG

OBJECTIVE

To determine if a simplified model for predicting pre-eclampsia (PEC) can be developed by combining first-trimester serum analytes, pregnancy-associated plasma protein A (PAPP-A) and free beta human chorionic gonadotrophin (β-hCG), and maternal characteristics.

METHODS

A retrospective cohort study of patients seen for first-trimester aneuploidy screening from 2003 to 2009. The 5th, 10th, 90th, and 95th percentiles for the analyte multiples of the medians (MoMs) for our population were determined and evaluated for association with PEC. Univariate and backward stepwise logistic regression analyses were performed and the area under the receiver operating characteristic (ROC) curves [area under curve (AUC)] used to determine the best models for predicting PEC.

RESULTS

Among 4020 women meeting the inclusion criteria, outcome data was available for 3716 (93%). There were 293 cases of PEC. The final model identified a history of pre-gestational diabetes [aOR 2.6, 95% confidence interval (CI) 1.7-3.9], chronic hypertension (cHTN) (aOR 2.6, 95% CI 1.7-3.9), maternal body mass index (BMI) > 25 (aOR 2.5, 95% CI 1.9-3.4), African American race (aOR 1.8, 95% CI 1.3-2.6), and PAPP-A MoM < 10th percentile (aOR 1.6, 95% CI 1.1-2.4) to be significant predictors of PEC (AUC = 0.70, 95% CI 0.65-0.72).

CONCLUSION

Low first-trimester PAPP-A levels are associated with the development of PEC; however, the model was only modestly efficient in its predictive ability.

The role of serum markers and uterine artery Doppler in identifying at-risk pregnancies

Measures of placental dysfunction, including maternal serum analytes and Doppler studies, have been linked to adverse pregnancy outcomes, although the predictive ability of any single one is poor. Improved knowledge of the multifactorial nature of many of the adverse outcomes of pregnancy has sparked interest in the use of multi-parameter models that combine maternal serum analytes with measures of placental structure and blood flow. The combination of various first-trimester and second-trimester analytes and uterine artery Doppler screening show promise as potential screening tools, but large prospective studies are needed to further define their role in clinical practice.

First-trimester serum analytes, biophysical tests and the association with pathological morphometry in the placenta of pregnancies with preeclampsia and fetal growth restriction

OBJECTIVE

We test the hypothesis that first-trimester serum analytes, 4-D power Doppler placental vascular indices and uterine artery Doppler (UAD) predicts abnormal placental morphometry in pregnancies with preeclampsia (PE) and fetal growth restriction (FGR).

STUDY DESIGN

Maternal serum analytes (PAPP-A, hCG, ADAM12s, and PP13), bilateral UADs, and placental vascular indices were measured at 11-14 weeks in a nested-case control study within a prospective cohort of women followed from the first-trimester to delivery. Vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were obtained from 4-D power Doppler histograms. Serum analytes were measured using immunofluorometric assays and values converted to multiples of the median (MoM) for gestational age. Morphometric analysis was performed on placentas from pregnancies complicated by PE (n = 13), gestational hypertension (HBP, n = 7) and FGR (defined as fetal weight <10th percentile with abnormal umbilical artery Doppler: n = 7); and 20 uncomplicated pregnancies. Two pregnancies had both FGR and PE. Each placenta was weighed and random samples taken, and fixed in formalin within 1 h of delivery. Hematoxylin & Eosin stained slides were analyzed by design-based stereology to quantify linear dimensions, surface areas and volumes of placental components. Paired t-test and ANOVA with adjustments for multiple comparisons were used.

RESULTS

The surface areas of terminal and intermediate villi as well as the volume of terminal villi were significantly smaller in placentas from pregnancies complicated by FGR and PE. Compared with the control group the mean PAPP-A (MoM) was lower in the pregnancies with abnormal placenta morphometry (1.1 ± 0.5 versus 0.7 ± 0.5, P = 0.03). The morphometric indices were lower in those pregnancies with low PAPP-A and IUGR compared with preeclampsia.

CONCLUSION

First-trimester PAPP-A levels are associated with abnormal placental morphometry at delivery in pregnancies with PE and IUGR. These findings may explain the association between adverse pregnancy outcomes and first-trimester PAPP-A.

Decreased placental expression of hPGH, IGF-I and IGFBP-1 in pregnancies complicated by fetal growth restriction

OBJECTIVE

The human Placental Growth Hormone (hPGH) and the Insulin-like Growth Factor (IGF) system are implicated in fetal development. This study aimed to evaluate the expression of hPGH, IGF-I, IGFBP-1 and IGFBP-3 genes in placentas from pregnancies complicated by fetal growth restriction (FGR).

DESIGN

The study group was comprised of term placentas from 47 FGR-complicated pregnancies of no recognizable cause. Thirty-seven placentas from normal pregnancies with appropriate for gestational age birth weight were used as controls. The expression status of the genes was evaluated by quantitative real-time PCR.

RESULTS

hPGH, IGF-I and IGFBP-1 exhibited significantly lower expression compared to the controls (p=0.003, p=0.049 and p=0.001, respectively). Numerically, lower IGFBP-3 expression was also demonstrated in the FGR-affected group, without however reaching statistical significance (p=0.129). Significant co-expression patterns were detected among the study genes in both the FGR and normal pregnancies.

CONCLUSION

Decreased placental expression levels of hPGH, IGF-I and IGFBP-1 were demonstrated in pregnancies with FGR. Whether these alterations are a causative factor of FGR or accompany other pathogenetic mechanisms requires further investigation.

The synthesis and secretion of inhibins

Inhibin A and B, dimeric glycoproteins comprising an α- and β((A/B))-subunit, negatively regulate follicle stimulating hormone (FSH) synthesis by the pituitary. The expression of α- and β-subunits within Sertoli cells of the testis and granulosa cells of the ovary is controlled by a range of transcription factors, including CREB, SP-1, Smads, and GATA factors. The inhibin α- and β-subunits are synthesized as precursor molecules consisting of an N-terminal propeptide and a C-terminal mature domain. Recently, we showed that hydrophobic residues within the propeptides of the α- and β-subunits interact noncovalently with their mature domains, maintaining the molecules in a conformation competent for dimerization. Dimeric precursors are cleaved by proprotein convertases and mature inhibins are secreted from the cell noncovalently associated with their propeptides. Propeptides may increase the half-life of inhibin A and B in circulation, but they are readily displaced in the presence of the high-affinity receptors, betaglycan, and ActRII.

Circulating predictive biomarkers in preeclampsia

The aim of the paper was to review promising prediction biomarkers for preeclampsia. The methods included review of abstracts on PubMed, using "preeclampsia", "biomarker", "prediction" as key words, followed by review of primary papers investigating blood based biomarkers. Angiogenic factors, such as PlGf and sFlt1, and PP13 seem presently to have the best predictive test values for preeclampsia, but sensitivity and specificity is still too low to prove useful in a population screening setting. Biomarker testing should still be part of research protocols. Biomarkers could provide useful in selecting high-risk women for prophylactic trials as well as identifying pregnancies that could profit from closer follow-up.

Risk factors and prediction of preeclampsia

Inadequate trophoblast invasion of the spiral arteries in early pregnancy, an increased inflammatory response and changes in the immune answer to paternal antigens are considered aetiological factors in preeclampsia. Searching for factors related to these angiogenic, anti-angiogenic, immunologic and inflammatory mechanisms may provide methods to determine which patient will develop preeclampsia predating the onset of the clinical manifestations of the disease. Screening for preeclampsia in the first trimester has had Limited success. Currently, maternal characteristics, clinical history, maternal serum biochemistry and uterine artery Doppler sonography before 14 weeks are being investigated. Preeclampsia in a previous pregnancy is still the strongest predictor. In the second trimester, uterine artery Doppler has a detection rate around 60% but also a high false positive rate of 25%. First trimester uterine artery Doppler studies have high sensitivity but poor specificity with a high false positive rate. Combination of first trimester uterine artery Doppler with patient characteristics and maternal serum biochemistry, specifically placental protein 13 holds promise but further evaluation is needed. Maternal serum markers including inhibin A, activin A, soluble FMS-Like tyrosine kinase 1, endoglin, pregnancy associated plasma protein A and others, when used alone have proved poor predictors of preeclampsia. Most studies have been performed by a limited group of researchers in a population with a high risk and no validation studies of any method in other populations are available. Results are difficult to compare due to differences in methodology, and differences in the end point studied.There are still no good methods of preventing preeclampsia once a high risk has been determined.

Hereditary thrombophilia and recurrence of ischemic placental disease

OBJECTIVE

We sought to evaluate whether testing for hereditary thrombophilia alone or in combination with second-trimester uterine artery Doppler (UAD) is useful in predicting recurrent complications in patients with previous preeclampsia, placental abruption, or stillbirth.

STUDY DESIGN

Between 2001 and 2005, 110 consecutive women were included in the study and received 100 mg of aspirin daily. Adjustment was made for several maternal confounding factors using a logistic regression model.

RESULTS

After multivariable logistic regression analyses, only abnormal UAD assessment was significantly associated with recurrent complications (odds ratio, 11.2; 95% confidence interval, 3.8-32.6) Combining the results of UAD and the presence of laboratory markers of thrombophilia failed to improve the accuracy of UAD to predict recurrent complications.

CONCLUSION

Hereditary thrombophilia testing is not useful in predicting recurrent complications in subsequent pregnancy.

Combining biochemical and ultrasonographic markers in predicting preeclampsia: a systematic review

BACKGROUND

Early identification of pregnant women at risk for preeclampsia is a priority to implement preventive measures. Some biochemical and ultrasonographic parameters have shown promising predictive performance, but so far there is no clinically validated screening procedure.

CONTENT

Using a series of keywords, we reviewed electronic databases (Medline, Embase, all records to May 2009) reporting the performance of biological and ultrasonographic markers to predict preeclampsia, both single markers and combinations of markers. We analyzed the data according to gestational age and risk levels of the studied populations. We evaluated the methodological quality of included publications using QUADAS (quality assessment of diagnostic accuracy studies). We identified 37 relevant studies that assessed 71 different combinations of biochemical and ultrasonographic markers. Most studies were performed during the second trimester on small-scale high-risk populations with few cases of preeclampsia. Combinations of markers generally led to an increase in sensitivity and/or specificity compared with single markers. In low-risk populations, combinations including placental protein 13 (PP13), pregnancy-associated plasma protein A (PAPP-A), a disintegrin and metalloprotease-12 (ADAM12), activin A, or inhibin A measured in first or early second trimester and uterine artery Doppler in second trimester appear promising (sensitivity 60%-80%, specificity >80%). In high-risk populations, the combination of PP13 and pulsatility index in first trimester showed 90% sensitivity and 90% specificity in a single study limited to severe preeclampsia.

SUMMARY

Combinations of biochemical and ultrasonographic markers improved the performance of early prediction of preeclampsia. From a perspective of integrative medicine, large population-based studies evaluating algorithms combining multiple markers are needed, if screening approaches are to be eventually implemented.