The perinatal implications of angiogenic factors

Circulating s-Endoglin concentrations in non-obese patients with gestational diabetes mellitus

The aim of this study was to compare maternal concentrations of soluble Endodlin (s-Endoglin) in women with gestational diabetes (GDM) and women with normal glucose tolerance (NGT) in pregnancy. Also, the association of insulin resistance markers and s-Endoglin was investigated. Forty patients complicated by GDM and forty gestational age-matched healthy pregnant women with NGT were included in the present study. s-Endoglin level was higher in patients with GDM compared with the control group (p .01). Besides a positive correlation was found between s-Endoglin and fasting glucose (r = 0.206, p = .057), insulin (r = 0.302, p = .005), HbA1c (r = 0.376, p < .01), HOMA-IR values (r = 0.283, p = .008) in pregnant women included in the study. s-Endoglin, as an anti-angiogenic marker seemed to have a role in pathogenesis and significantly associated with insulin resistance markers in non-obese GDM, thus may play important roles in the regulation of glucose hemostasis.Impact StatementWhat is already known on this subject? In women with GDM, hyperglycaemia induced glycosylation products might cause oxidative stress that may be subsequently involved in the release of inflammatory mediators, inducing angiogenesisWhat the results of this study add? s-Endoglin has an anti-angiogenic effect and is a useful marker of endothelial injury, activation of inflammation, senescence and oxidative stress, we speculate that it may be involved in the pathogenesis of GDM.What the implications are of these findings for clinical practice and/or further research? s-Endoglin seemed to have a role in the regulation of glucose hemostasis. Further exploration of novel factors like s-endoglin in the pathogenesis of GDM, is essential and valuable to develop new therapeutic strategies for this complex disease and its complications.

First trimester 3D ultrasound placental volume for predicting preeclampsia and/or intrauterine growth restriction

The objective of the study was to determine the sensitivity of the placental volume for predicting preeclampsia and/or intrauterine growth restriction (IUGR) in the first trimester. A prospective observational study was conducted in pregnant women with a gestational age of 11 to 13⁺⁶ weeks. A 3 D transabdominal placental volume measurement was performed at the time of first-trimester aneuploidy screening. The predictive values of this test were calculated. The data from 360 pregnant women was analysed. Seventeen cases developed preeclampsia and/or IUGR. The 10^th percentile of placental volume was used as the cut-off level. The sensitivity, specificity, positive predictive value and negative predictive value of placental volume less than the 10^th percentile for prediction of preeclampsia and/or IUGR were 23.5%, 90.7%, 11.1% and 96%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value for prediction of early onset preeclampsia were 50%, 90.7%, 3.0% and 99.7%, respectively. This study demonstrated that the placental volume was lower in the cases with preeclampsia and/or IUGR. It was not an effective screening tool for preeclampsia and/or IUGR in the first trimester. IMPACT STATEMENT What is already known on this subject? Placental volume may reflect trophoblast invasion, but much earlier, in the first trimester. The estimation of a smaller early placental volume has been shown to be significantly associated with preeclampsia and IUGR. What do the results of this study add? The placental volume was lower in the cases with preeclampsia and/or IUGR. It was not an effective screening tool for preeclampsia and/or IUGR in the first trimester. But it might be used for predicting early onset preeclampsia. What are the implications of these findings for clinical practice and/or further research? Further research of placental volume in the first trimester for predicting an early onset preeclampsia should be conducted.

Early second trimester maternal serum markers in the prediction of gestational diabetes mellitus

AIMS/INTRODUCTION

To determine whether maternal serum markers in the early second trimester are useful for prediction of gestational diabetes mellitus (GDM).

MATERIALS AND METHODS

A total of 876 singleton pregnancies were recruited in the present study. Blood samples were collected during 16-20 gestational weeks. GDM women were diagnosed by an oral glucose tolerance test during 24-28 gestational weeks. A total of 56 women with GDM and 73 healthy pregnant women were selected. Maternal serum concentrations of placental protein 13 (PP13), pentraxin 3 (PTX3), soluble fms-like tyrosine kinase-1 (sFlt-1), myostatin and follistatin (FST) were detected at 16-20 weeks' gestation. All of these markers concentrations were expressed as multiples of the medians. The Mann-Whitney U-test was used for comparison of the multiples of the medians of different concentrations of these five serum markers between the GDM group and the control group. Receiver operating characteristic curve analysis was applied to assess the sensitivity and specificity of significant serum markers from a Mann-Whitney U-test comparison.

RESULTS

Compared with healthy pregnancies, the serum levels of PP13, PTX3, sFlt-1, myostatin and FST in the early second trimester were significantly increased in patients who had developed GDM late. In screening for GDM by PP13, PTX3, sFlt-1, myostatin and FST, the detection rates were 92.3, 94.9, 94.9, 92.5 and 92.3%, respectively at 80% specificity. PTX3 and sFlt-1 were the most sensitive markers.

CONCLUSIONS

Maternal serum markers including PP13, PTX3, sFlt-1, myostatin and FST increase in the early second trimester of women with GDM. These five markers, especially PTX3 and sFlt-1, could have the value of prediction for those patients who would develop GDM in the late second trimester.

Gestational glucocorticoid exposure disrupts glucose homeostasis that is accompanied by increased endoglin and DPP-4 activity instead of GSK-3 in rats

Gestational glucocorticoid (GC) treatment has been associated with cardiometabolic disorder (CMD) in offspring's in later life. Elevated dipeptidyl peptidase-4 (DPP-4) activity, endoglin and glycogen synthase kinase-3 (GSK-3) has also been implicated in the development of insulin resistance (IR) and/or vascular inflammation. We aimed to investigate the impact of GC exposure on glucose metabolism and the circulating levels of inflammatory biomarkers, DPP-4 activity and GSK-3 in pregnant rats. Pregnant Wistar rats received either vehicle or dexamethasone (DEX; 0.2 mg/kg; po) between gestational days 14 and 19. Gestational GC exposure resulted in impaired glucose homeostasis that is accompanied with elevated circulating levels of inflammatory biomarkers (endoglin, uric acid, and platelet/lymphocyte ratio), oxidative stress (malondialdehyde), blood viscosity, reduced NO level and increased DPP-4 activity. However, these effects were associated with atherogenic dyslipidemia and reduced GSK-3.We conclude that plasma endoglin, a marker of vascular inflammation, and plasma DPP-4 activity are increased in pregnant rats treated with GC during late gestation. Therefore, glucose deregulation associated with gestational GC exposure is through endoglin-/DPP-4-dependent but GSK-3-independent pathway.

Systematic review of maternal Placental Growth Factor levels in late pregnancy as a predictor of adverse intrapartum and perinatal outcomes

AIM

This systematic review evaluates the utility of maternal Placental Growth Factor (PlGF) when measured in late pregnancy (>20 weeks) as a predictor of adverse obstetric and perinatal outcomes.

METHODS

Pubmed and Embase were searched using the term "placental growth factor" in combination with relevant perinatal outcomes. Studies were included if they measured PlGF levels in pregnant women after 20 + 0 weeks gestation and reported relevant adverse obstetric or perinatal outcomes related to placental insufficiency (excluding pre-eclampsia).

RESULTS

Twenty-six studies were eligible for inclusion with 21 studies investigating the relationship between PlGF and small for gestational age (SGA) and 7 studies investigating PlGF for the prediction of other adverse perinatal outcomes. In all studies, maternal PlGF levels were significantly lower in the SGA group compared to controls. Other outcomes investigated included caesarean section (CS) for fetal compromise, low Apgar score, neonatal intensive care unit (NICU) admission, neonatal acidosis, stillbirth, and intrapartum fetal compromise. The results generally showed a significant association between low PlGF levels and CS for fetal compromise, NICU admission and stillbirth.

CONCLUSION

Low maternal PlGF levels in late pregnancy are strongly associated with SGA. Findings across studies were variable in relation to PlGF and the prediction of other adverse intrapartum and perinatal outcomes, however there was a consistent association between low PlGF levels and CS for fetal compromise, NICU admission and stillbirth. This review suggests that the use of PlGF for the prediction of adverse outcomes is promising. Its predictive value may potentially be enhanced if used in combination with other biomarkers or biophysical measures of fetal well-being.

Profile of CYP19A1 mRNA expression and aromatase activity during syncytialization of primary human villous trophoblast cells at term

Estrogen production by the human villous trophoblast is dependent on the biosynthetic enzyme aromatase (CYP19; CYP19A1) and is crucial for successful placental development and pregnancy outcome. Using villous cytotrophoblast cells (vCTs) freshly isolated from normal term placenta, we characterized the promoter-specific expression of CYP19A1 mRNA (derived from promoters I.1, I.4, I.8 or total transcript) and aromatase activity during villous trophoblast syncytialization. CYP19A1 mRNA levels and aromatase activity in vCTs reached a maximum after about 48 h of culture. The cAMP inducer forskolin (10 μM) and protein kinase C stimulant phorbol myristate acetate (1 μM) increased CYP19A1 mRNA levels by 1.8- and 1.6-fold, respectively, as well as inducing aromatase catalytic activity. Dexamethasone (100 nM) and vascular endothelial growth factor (5 ng/mL) decreased CYP19A1 mRNA levels, while having no effect on aromatase activity. Our results emphasize the importance of not solely studying CYP19A1 regulation and function at the mRNA level but also considering posttranslational mechanisms that alter the final catalytic activity of aromatase.

Longitudinal changes in maternal serum placental growth factor and soluble fms-like tyrosine kinase-1 in women at increased risk of pre-eclampsia

OBJECTIVES

To investigate longitudinal changes in maternal serum levels of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) in pregnant women who develop pre-eclampsia (PE) or gestational hypertension (GH).

METHODS

This was a prospective longitudinal study in women with singleton pregnancies identified by screening at 11 + 0 to 13 + 6 weeks' gestation as being at high-risk of PE. Blood samples were taken every 4 weeks until delivery. Values were compared in women who developed preterm PE (requiring delivery before 37 weeks' gestation), term PE or GH and those who remained normotensive.

RESULTS

A total of 1069 samples were analyzed in 234 women, including 172 who remained normotensive, 18 who developed GH, 22 who developed preterm PE and 22 who developed term PE. In the preterm PE group, compared to the normotensive group, sFlt-1 levels were significantly higher from 15 weeks' gestation onward and the difference increased with gestational age (P < 0.001). In the preterm PE group, compared to the normotensive group, PlGF levels were significantly lower from 11 weeks' gestation onward and the difference increased significantly with gestational age (P < 0.001). Similarly, in the term PE and GH groups, PlGF levels were lower from 13 and 27 weeks onward, respectively, and the differences increased significantly with gestational age (P < 0.001 for both groups). In the preterm PE group, compared to the normotensive group, the sFlt-1/PlGF ratio was significantly higher from 11 weeks onward and the difference increased significantly with gestational age (P < 0.001). A random slope model provided a significantly better fit to the data than did a single-level model for sFlt-1 (likelihood ratio (LR) = 516; degrees of freedom (df) = 3; P < 0.001), PlGF (LR = 542; df = 3; P < 0.001) and the sFlt-1/PlGF ratio (LR = 468; df = 3; P < 0.001).

CONCLUSION

Repeat measurements of the biochemical markers used in this study are likely to be better predictors of PE than are measurements at a single time point during pregnancy, as the differences between normotensive and hypertensive pregnancies increase with gestational age. In screening for preterm PE, maternal serum level of PlGF is a useful marker from the first trimester onward, while the level of sFlt-1 is likely to have a predictive value from the second trimester onward. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Six Novel Loci Associated with Circulating VEGF Levels Identified by a Meta-analysis of Genome-Wide Association Studies

Vascular endothelial growth factor (VEGF) is an angiogenic and neurotrophic factor, secreted by endothelial cells, known to impact various physiological and disease processes from cancer to cardiovascular disease and to be pharmacologically modifiable. We sought to identify novel loci associated with circulating VEGF levels through a genome-wide association meta-analysis combining data from European-ancestry individuals and using a dense variant map from 1000 genomes imputation panel. Six discovery cohorts including 13,312 samples were analyzed, followed by in-silico and de-novo replication studies including an additional 2,800 individuals. A total of 10 genome-wide significant variants were identified at 7 loci. Four were novel loci (5q14.3, 10q21.3, 16q24.2 and 18q22.3) and the leading variants at these loci were rs114694170 (MEF2C, P = 6.79x10^-13), rs74506613 (JMJD1C, P = 1.17x10^-19), rs4782371 (ZFPM1, P = 1.59x10^-9) and rs2639990 (ZADH2, P = 1.72x10^-8), respectively. We also identified two new independent variants (rs34528081, VEGFA, P = 1.52x10^-18; rs7043199, VLDLR-AS1, P = 5.12x10^-14) at the 3 previously identified loci and strengthened the evidence for the four previously identified SNPs (rs6921438, LOC100132354, P = 7.39x10^-1467; rs1740073, C6orf223, P = 2.34x10^-17; rs6993770, ZFPM2, P = 2.44x10^-60; rs2375981, KCNV2, P = 1.48x10^-100). These variants collectively explained up to 52% of the VEGF phenotypic variance. We explored biological links between genes in the associated loci using Ingenuity Pathway Analysis that emphasized their roles in embryonic development and function. Gene set enrichment analysis identified the ERK5 pathway as enriched in genes containing VEGF associated variants. eQTL analysis showed, in three of the identified regions, variants acting as both cis and trans eQTLs for multiple genes. Most of these genes, as well as some of those in the associated loci, were involved in platelet biogenesis and functionality, suggesting the importance of this process in regulation of VEGF levels. This work also provided new insights into the involvement of genes implicated in various angiogenesis related pathologies in determining circulating VEGF levels. The understanding of the molecular mechanisms by which the identified genes affect circulating VEGF levels could be important in the development of novel VEGF-related therapies for such diseases.

Vascular Endothelial Growth Factor (VEGF) is a protein with a fundamental role in development of vascular system. The protein, produced by many types of cells, is released in the blood. High levels of VEGF have been observed in different pathological conditions especially in cancer, cardiovascular, and inflammatory diseases. Therefore, identifying the genetic factors influencing VEGF levels is important for predicting and treating such pathologies. The number of genetic variants associated with VEGF levels has been limited. To identify new loci, we have performed a Genome Wide Association Study meta-analysis on a sample of more than 16,000 individuals from 10 cohorts, using a high-density genetic map. This analysis revealed 10 variants associated with VEGF circulating levels, 6 of these being novel associations. The 10 variants cumulatively explain more than 50% of the variability of VEGF serum levels. Our analyses have identified genes known to be involved in angiogenesis related diseases and genes implicated in platelet metabolism, suggesting the importance of links between this process and VEGF regulation. Overall, these data have improved our understanding of the genetic variation underlying circulating VEGF levels. This in turn could guide our response to the challenge posed by various VEGF-related pathologies.

Quantification of preeclampsia-related microRNAs in maternal serum

To identify the specific serum preeclampsia (PE)-related biomarkers, 10 microRNAs (miRNAs) were selected based on their reported aberrant (4 upregulated and 6 downregulated) expression in PE placenta. A total of 1,035 pregnant patients were enrolled. Finally, 32 pregnancies with PE and 32 healthy pregnancies were incorporated in the study. The expression of these 10 miRNAs in the different trimesters was determined by SYBR-Green reverse transcription-quantitative polymerase chain reaction. Compared with that in the healthy controls, the expression levels of miR-152, miR-183 and miR-210 in PE serum were higher in the second and third trimester, whereas the expression of miR-182 was only higher in the third trimester. The expression levels of 6 miRNAs (miR-1, miR-328, miR-363, miR-377, miR-500 and miR-584) that were downregulated in PE placenta showed no significant differences between pregnancies complicated by PE and healthy pregnancies throughout the 3 trimesters. Areas under the receiver operating characteristic [standard error (SE)] during the 20-24th gestational week for predicting PE were miR-152: 0.94 (SE, 0.026), miR-183: 0.97 (SE, 0.031) and miR-210: 0.93 (SE, 0.018). In conclusion, the expression levels of serum miR-152, miR-183 and miR-210 were elevated since the second trimester in pregnancies complicated with PE, indicating their potentials as serum biomarkers for forecasting PE.

Massive ascites in a patient with preeclampsia

Preeclampsia is a systemic endothelial disorder triggered by many factors originated by the human placenta. The presence of massive ascites (more than 2 L of serous liquid in peritoneal cavity) signifies rare and severe complication of preeclampsia. We present a case of 25-year-old primigravida admitted to hospital due to preeclampsia who immediately after delivery developed a clinical condition similar to hemorrhagic shock, but the explorative laparotomy revealed only massive ascites of 4.5 L serous liquid. We suggest that appearance of massive ascites in women with preeclampsia is the underestimated fact that surprises us frequently. Sometimes, its sudden onset can mimic life-threatening conditions, as happened with our patient. Cautious evaluation of peritoneal fluid quantity in women with preeclampsia could warn the obstetrician about the potential risks that demand more intensive and more frequent maternal and fetal surveillance.

Full-length human placental sFlt-1-e15a isoform induces distinct maternal phenotypes of preeclampsia in mice

OBJECTIVE

Most anti-angiogenic preeclampsia models in rodents utilized the overexpression of a truncated soluble fms-like tyrosine kinase-1 (sFlt-1) not expressed in any species. Other limitations of mouse preeclampsia models included stressful blood pressure measurements and the lack of postpartum monitoring. We aimed to 1) develop a mouse model of preeclampsia by administering the most abundant human placental sFlt-1 isoform (hsFlt-1-e15a) in preeclampsia; 2) determine blood pressures in non-stressed conditions; and 3) develop a survival surgery that enables the collection of fetuses and placentas and postpartum (PP) monitoring.

METHODS

Pregnancy status of CD-1 mice was evaluated with high-frequency ultrasound on gestational days (GD) 6 and 7. Telemetry catheters were implanted in the carotid artery on GD7, and their positions were verified by ultrasound on GD13. Mice were injected through tail-vein with adenoviruses expressing hsFlt-1-e15a (n = 11) or green fluorescent protein (GFP; n = 9) on GD8/GD11. Placentas and pups were delivered by cesarean section on GD18 allowing PP monitoring. Urine samples were collected with cystocentesis on GD6/GD7, GD13, GD18, and PPD8, and albumin/creatinine ratios were determined. GFP and hsFlt-1-e15a expression profiles were determined by qRT-PCR. Aortic ring assays were performed to assess the effect of hsFlt-1-e15a on endothelia.

RESULTS

Ultrasound predicted pregnancy on GD7 in 97% of cases. Cesarean section survival rate was 100%. Mean arterial blood pressure was higher in hsFlt-1-e15a-treated than in GFP-treated mice (∆MAP = 13.2 mmHg, p = 0.00107; GD18). Focal glomerular changes were found in hsFlt-1-e15a -treated mice, which had higher urine albumin/creatinine ratios than controls (109.3 ± 51.7 μg/mg vs. 19.3 ± 5.6 μg/mg, p = 4.4 x 10(-2); GD18). Aortic ring assays showed a 46% lesser microvessel outgrowth in hsFlt-1-e15a-treated than in GFP-treated mice (p = 1.2 x 10(-2)). Placental and fetal weights did not differ between the groups. One mouse with liver disease developed early-onset preeclampsia-like symptoms with intrauterine growth restriction (IUGR).

CONCLUSIONS

A mouse model of late-onset preeclampsia was developed with the overexpression of hsFlt-1-e15a, verifying the in vivo pathologic effects of this primate-specific, predominant placental sFlt-1 isoform. HsFlt-1-e15a induced early-onset preeclampsia-like symptoms associated with IUGR in a mouse with a liver disease. Our findings support that hsFlt-1-e15a is central to the terminal pathway of preeclampsia, and it can induce the full spectrum of symptoms in this obstetrical syndrome.

In vivo experiments reveal the good, the bad and the ugly faces of sFlt-1 in pregnancy

Objective

Soluble fms-like tyrosine kinase (sFlt)-1-e15a, a primate-specific sFlt-1-isoform most abundant in the human placenta in preeclampsia, can induce preeclampsia in mice. This study compared the effects of full-length human (h)sFlt-1-e15a with those of truncated mouse (m)sFlt-1(1-3) used in previous preeclampsia studies on pregnancy outcome and clinical symptoms in preeclampsia.

Methods

Mice were injected with adenoviruses or fiber-mutant adenoviruses overexpressing hsFlt-1-e15a, msFlt-1(1-3) or control GFP under the CMV or CYP19A1 promoters on gestational day 8 (GD8) and GD11. Placentas and pups were delivered by cesarean section, and dams were monitored postpartum. Blood pressure was telemetrically recorded. Urine samples were collected with cystocentesis and examined for albumin/creatinine ratios. Tissue specimens were evaluated for transgene as well as endogenous mFlt-1 and msFlt-1-i13 expression. H&E-, Jones- and PAS-stained kidney sections were histopathologically examined. Placental GFP expression and aortic ring assays were investigated with confocal microscopy.

Results

Mean arterial blood pressure (MAP) was elevated before delivery in hsFlt-1-e15a-treated mice compared to controls (GD18: ΔMAP = 7.8 mmHg, p = 0.009), while ΔMAP was 12.8 mmHg (GD18, p = 0.005) in msFlt-1(1-3)-treated mice. Urine albumin/creatinine ratio was higher in hsFlt-1-e15a-treated mice than in controls (GD18, p = 0.04; PPD8, p = 0.03), and msFlt-1(1-3)-treated mice had marked proteinuria postpartum (PPD8, p = 4×10⁻⁵). Focal glomerular changes were detected in hsFlt-1-e15a and msFlt-1(1-3)-treated mice. Aortic ring microvessel outgrowth was decreased in hsFlt-1-e15a (p = 0.007) and msFlt-1(1-3)-treated (p = 0.02) mice. Full-length msFlt-1-i13 expression was unique for the placenta. In hsFlt-1-e15a-treated mice, the number of pups (p = 0.046), total weight of living pups (p = 0.04) and maternal weights (p = 0.04) were higher than in controls. These differences were not observed in truncated msFlt-1(1-3)-treated mice.

Conclusions

Truncated msFlt-1(1-3) simulated the preeclampsia-promoting effects of full-length hsFlt-1. MsFlt-1(1-3) had strong effect on maternal endothelium but not on placentas and embryos. In contrast, hsFlt-1-e15a induced preeclampsia-like symptoms; however, it also increased litter size. In accord with the predominant placental expression of hsFlt-1-e15a and msFlt-1-i13, full-length sFlt-1 may have a role in the regulation of embryonic development. These observations point to the difference in the biological effects of full-length and truncated sFlt-1 and the changes in the effect of full-length sFlt-1 during pregnancy, and may have important implications in the management of preeclampsia.

Longitudinal changes in maternal soluble endoglin and angiopoietin-2 in women at risk for pre-eclampsia

OBJECTIVE

To investigate longitudinal changes in maternal plasma levels of soluble endoglin (sEng) and angiopoietin-2 (Ang-2) in pregnant women who develop pre-eclampsia (PE) and gestational hypertension (GH).

METHODS

This was a nested case-control study drawn from a larger prospective longitudinal study in singleton pregnancies identified by screening at 11 + 0 to 13 + 6 weeks' gestation as being at high-risk for PE. Blood samples were taken every 4 weeks until delivery. Values were compared in women who developed preterm PE (requiring delivery before 37 weeks), term PE, GH and those who remained normotensive.

RESULTS

A total of 471 samples were analyzed in 122 women, comprising 85 who remained normotensive, 12 who developed GH, 13 who developed term PE and 12 who developed preterm PE. In the normotensive group, there was an increase in log10 sEng levels with gestational age. In the preterm PE group, compared with the normotensive group, sEng was higher from 18 weeks onwards, and the difference increased significantly with gestational age (P < 0.001). In the GH and term PE groups, sEng did not differ significantly from that of the normotensive group (P = 0.583 and P = 0.890, respectively). The square root of Ang-2 decreased significantly with gestational age, but did not differ significantly among the different outcome groups (P = 0.571).

CONCLUSION

Maternal plasma sEng, but not Ang-2, may be a useful mid- and late-gestation biomarker for the development of PE.

Pre-eclampsia part 2: prediction, prevention and management

An antiangiogenic state might constitute a terminal pathway for the multiple aetiologies of pre-eclampsia, especially those resulting from placental abnormalities. The levels of angiogenic and antiangiogenic proteins in maternal blood change prior to a diagnosis of pre-eclampsia, correlate with disease severity and have prognostic value in identifying women who will develop maternal and/or perinatal complications. Potential interventions exist to ameliorate the imbalance of angiogenesis and, hence, might provide opportunities to improve maternal and/or perinatal outcomes in pre-eclampsia. Current strategies for managing pre-eclampsia consist of controlling hypertension, preventing seizures and timely delivery of the fetus. Prediction of pre-eclampsia in the first trimester is of great interest, as early administration of aspirin might reduce the risk of pre-eclampsia, albeit modestly. Combinations of biomarkers typically predict pre-eclampsia better than single biomarkers; however, the encouraging initial results of biomarker studies require external validation in other populations before they can be used to facilitate intervention in patients identified as at increased risk. Angiogenic and antiangiogenic factors might also be useful in triage of symptomatic patients with suspected pre-eclampsia, differentiating pre-eclampsia from exacerbations of pre-existing medical conditions and performing risk assessment in asymptomatic women. This Review article discusses the performance of predictive and prognostic biomarkers for pre-eclampsia, current strategies for preventing and managing the condition and its long-term consequences.

Concentrations of human chorionic gonadotrophin in very early pregnancy and subsequent pre-eclampsia: a cohort study

STUDY QUESTION

Are low serum concentrations of human chorionic gonadotrophin (hCG) in very early pregnancy associated with pre-eclampsia risk?

SUMMARY ANSWER

Low hCG concentrations in very early pregnancy are associated with increased risk of severe pre-eclampsia.

WHAT IS KNOWN ALREADY

Low maternal serum concentrations of hCG early in pregnancy may indicate impaired proliferation or invasion of trophoblast cells, and thus low hCG concentrations may serve as a marker for impaired placental development. Impaired placental development is assumed to be a cause of pre-eclampsia, but there is little prospective evidence to support this hypothesis.

STUDY DESIGN, SIZE, DURATION

We performed a prospective cohort study of pregnancies after IVF at Oslo University Hospital 1996-2010 with linkage to the Medical Birth Registry of Norway to obtain information on pre-eclampsia development.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included 2405 consecutive singleton pregnancies and examined the association of maternal serum hCG concentrations (measured using Elecsys, Roche) on Day 12 after embryo transfer with the risk of any pre-eclampsia and of mild and severe pre-eclampsia.

MAIN RESULTS AND THE ROLE OF CHANCE

HCG concentrations were inversely associated with pre-eclampsia risk in a dose-dependent manner (Ptrend 0.02). Compared with women with hCG ≥150 IU/l, women with hCG <50 IU/l were at 2-fold higher overall risk of pre-eclampsia [absolute risk 6.4 versus 2.8%; odds ratio (OR) 2.3, 95% confidence interval (CI) 1.2-4.7]. The inverse association was restricted to severe pre-eclampsia (Ptrend 0.01), thus, women with hCG <50 IU/l were at 4-fold higher risk of severe pre-eclampsia than women with hCG ≥150 IU/l (absolute risk 3.6 versus 0.9%; OR 4.2, 95% CI 1.4-12.2). For mild pre-eclampsia, there was no corresponding association (Ptrend 0.36).

LIMITATIONS, REASONS FOR CAUTION

Results for IVF pregnancies may not be generalizable to spontaneously conceived pregnancies.

WIDER IMPLICATIONS OF THE FINDINGS

Plausible causes of low maternal hCG concentrations very early in pregnancy include impaired placental development and delayed implantation. Thus, these results provide prospective evidence to support the hypothesis that impaired placental development may be associated with subsequent development of severe pre-eclampsia.

STUDY FUNDING/COMPETING INTEREST

The study was financially supported by the Research Council of Norway. None of the authors has any conflict of interest to declare.

Discordant clinical presentations of preeclampsia and intrauterine fetal growth restriction with similar pro- and anti-angiogenic profiles

OBJECTIVE

To evaluate the plasma levels of angiogenic factors in preeclampsia (PE) and intrauterine fetal growth restriction (IUGR) and their potential as biomarkers to distinguish normal from pathologic pregnancies.

METHODS

Case control study included singleton pregnancies in four categories: (i) normal (n = 29), (ii) PE (n = 15), (iii) PE and IUGR (n = 16) and (iv) IUGR (n = 24). The classification of IUGR included umbilical artery Doppler resistance. Maternal plasma placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), soluble kinase domain receptor (sKDR) and soluble endoglin (sEng) as well as fetal umbilical artery sFlt-1 levels were determined. Each individual marker and their ratios were assessed for their potential to distinguish normal pregnancy from pregnancies affected by PE and/or IUGR.

RESULTS

We found (i) elevated plasma sFlt-1, sEng and reduced PlGF, sKDR in PE and IUGR; (ii) similar angiogenic profiles in PE and IUGR and (iii) sEng and sFlt-1*sEng/PlGF performed best as biomarkers in identifying pathologic pregnancies.

CONCLUSIONS

PE and IUGR have similar angiogenic profiles, suggesting that angiogenic marker profiles lack specificity in identifying PE and that other factors are required for the development of PE instead of IUGR. sEng should be included in a biomarker profile for predicting PE or IUGR.

Maternal soluble fms-like tyrosine kinase-1, placental growth factor, plasminogen activator inhibitor-2, and folate concentrations and early fetal size: the Generation R study

OBJECTIVE

Fetal growth is dependent on adequate development of the placenta. Impaired angiogenesis and vasculogenesis in early pregnancy compromises placental and embryonic development. The proteins soluble fms-like tyrosine kinase (sFlt)-1, placental growth factor (PlGF), and plasminogen activator inhibitor (PAI)-2, and the B vitamin folate are determinants of placental development. This study aims to identify associations between these maternal biomarkers and early fetal size.

STUDY DESIGN

From a prospective birth cohort study in The Netherlands, 1491 pregnant women were selected for this study. At a mean gestational age (GA) of 12.4 weeks (SD 0.8) maternal venous blood samples were obtained to determine the concentrations of sFlt-1, PlGF, PAI-2, and folate. Early fetal size was assessed with measurement of the crown-to-rump length (CRL) at a mean of 12.4 weeks' GA (SD 0.8). Analyses were performed using multivariable linear regression analyses with the biomarkers (continuous, quintiles) as regressors and CRL as main outcome measure.

RESULTS

Linear trend analysis showed positive associations between maternal sFlt-1 (P < .001), PlGF (P = .042), PAI-2 (P < .001), and folate (P = .039) and CRL. These associations were independent of GA, maternal age, height, body mass index, ethnicity, fetal sex, parity, educational level, smoking, and folic acid supplement use (folate not adjusted).

CONCLUSION

sFlt-1, PlGF, PAI-2, and folate are positively associated with first-trimester fetal size.

Maternal plasma concentrations of angiogenic/antiangiogenic factors in the third trimester of pregnancy to identify the patient at risk for stillbirth at or near term and severe late preeclampsia

OBJECTIVE

To determine whether maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) at 30-34 weeks of gestation can identify patients at risk for stillbirth, late preeclampsia, and delivery of small-for-gestational-age (SGA) neonates.

STUDY DESIGN

A prospective cohort study included 1269 singleton pregnant women from whom blood samples were obtained at 30-34 weeks of gestation and who delivered at >34 weeks of gestation. Plasma concentrations of PlGF, sEng, and sVEGFR-1 were determined by enzyme-linked immunosorbent assay.

RESULTS

The prevalence of late (>34 weeks of gestation) preeclampsia, severe late preeclampsia, stillbirth, and SGA was 3.2% (n = 40), 1.8% (n = 23), 0.4% (n = 5), and 8.5% (n = 108), respectively. A plasma concentration of PlGF/sEng <0.3 MoM was associated with severe late preeclampsia (adjusted odds ratio, 16); the addition of PlGF/sEng to clinical risk factors increased the area under the receiver-operating characteristic curve from 0.76 to 0.88 (P = .03). The ratio of PlGF/sEng or PlGF/sVEGFR-1 in the third trimester outperformed those obtained in the first or second trimester and uterine artery Doppler velocimetry at 20-25 weeks of gestation for the prediction of severe late preeclampsia (comparison of areas under the receiver-operating characteristic curve; each P ≤ .02). Both PlGF/sEng and PlGF/sVEGFR-1 ratios achieved a sensitivity of 74% with a fixed false-positive rate of 15% for the identification of severe late preeclampsia. A plasma concentration of PlGF/sVEGFR-1 <0.12 MoM at 30-34 weeks of gestation had a sensitivity of 80%, a specificity of 94%, and a likelihood ratio of a positive test of 14 for the identification of subsequent stillbirth. Similar findings (sensitivity 80%; specificity 93%) were observed in a separate case-control study.

CONCLUSION

Risk assessment for stillbirth and severe late preeclampsia in the third trimester is possible with the determination of maternal plasma concentrations of angiogenic and antiangiogenic factors at 30-34 weeks of gestation.

Can maternal serum placental growth factor estimation in early second trimester predict the occurrence of early onset preeclampsia and/or early onset intrauterine growth restriction? A prospective cohort study

AIM

To determine whether maternal serum placental growth factor (PlGF) estimation in early second trimester (20-22 weeks of gestation) can predict the occurrence of early onset preeclampsia and/or early onset intrauterine growth restriction (IUGR).

MATERIAL AND METHODS

A prospective cohort study was conducted on 722 women with singleton pregnancies, screened from the antenatal clinic, and serum PlGF levels were estimated at 20-22 weeks of gestation. A cut-off value of <155 pg/mL for serum PlGF was determined by receiver operating characteristic (ROC) curve analysis for identifying pregnant women at risk of developing early onset preeclampsia and/or early onset IUGR. Preeclampsia and IUGR were classified as early onset when diagnosed by 32 weeks of gestation. Univariate logistic regression analysis was used to analyze the association between serum PlGF level <155 pg/mL and the two outcome measures (i.e. early onset preeclampsia and early onset IUGR) and odds ratio (OR) was computed. P-value < 0.05 was considered statistically significant.

RESULTS

Maternal serum PlGF level <155 pg/mL at 20-22 weeks of gestation had a strong association with early onset preeclampsia (OR 8.35; 95% CI 1.79-18.94; P = 0.007) and with early onset IUGR (OR 10.73; 95% CI 4.08-20.23; P = 0.000). The sensitivity of serum PlGF < 155 pg/mL for predicting early onset preeclampsia and early onset IUGR were 82 and 84, respectively.

CONCLUSION

Maternal serum PlGF level estimation in early second trimester (20-22 weeks of gestation) may be useful in predicting the occurrence of early onset preeclampsia and/or early onset IUGR.

Serum placental growth factor as a predictor of early onset preeclampsia in overweight/obese pregnant women

The purpose of this study was to analyze whether maternal serum placental growth factor (PlGF) could predict early onset preeclampsia (<32 weeks of gestation) in overweight/obese pregnant women, and whether it could do it more effectively than in normal/underweight pregnant women. A prospective cohort study was conducted on 1678 pregnant women with singleton pregnancies, who were grouped as underweight, normal, overweight, and obese on the basis of body mass index, followed by serum PlGF estimation at 20 to 22 weeks of gestation. A cut-off value of <144 pg/mL for PlGF was determined by Receiver Operating Characteristic curve analysis to identify risk of early onset preeclampsia. Univariate logistic regression analysis revealed significantly stronger association between PlGF <144 pg/mL and early onset preeclampsia in overweight/obese pregnant women (odds ratio 7.64; 95% confidence interval 5.34-10.12; P = .000) than in normal/underweight pregnant women (odds ratio 2.95; 95% confidence interval 1.74-4.26; P = .007). Weight and PlGF levels in study women had a significant negative correlation (r = 0.663; P = .002). Serum PlGF in early second trimester could be an effective predictor of early onset preeclampsia in overweight/obese pregnant women and may be more effective than in normal/underweight pregnant women.

The role of angiogenic, anti-angiogenic and vasoactive factors in pre-eclamptic African women: early- versus late-onset pre-eclampsia

Abstract

The pathogenesis and aetiology of pre-eclampsia (PE) is still unclear. We investigated the role of angiogenic, anti-angiogenic and vasoactive factors in black South African women with early- and late-onset PE. Serum soluble fms-like tyrosine kinase 1 (sFlt-1), soluble vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) levels were determined using the ELISA technique, and placental mRNA expression levels of sFlt-1, VEGF, PlGF and AT1 receptors were determined using real-time PCR.

Serum sFlt-1 levels were significantly elevated and PlGF significantly reduced in early-onset PE compared to the normotensive group. Placental VEGF mRNA expression levels were significantly reduced in the late-onset preeclamptic group compared with the normotensives. The placental mRNA expression of AT1 receptor in the late-onset pre-eclamptic group was relatively raised compared to the normotensives, suggesting hypersensitivity to pressor agents.

We believe that the excess of serum sFlt-1 and reduced VEGF and PlGF levels favour an anti-angiogenic state and endothelial dysfunction leading to PE, and that the aetiology and pathogenesis of early- and late-onset PE differ.

Angiogenic factors in maternal circulation and preeclampsia with or without fetal growth restriction

OBJECTIVE

To study associations of placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1) in maternal circulation with the risk of preeclampsia with and without fetal growth restriction.

DESIGN

Nested case-control study.

SETTING

A cohort of 29 948 pregnant women in Norway.

SAMPLE

Cases were identified through linkage to the Medical Birth Registry of Norway. We selected 69 preterm and 36 term preeclampsia cases with delivery of a small-for-gestational-age (SGA) infant, 83 preterm and 154 term preeclampsia cases without SGA delivery, and 384 normotensive controls.

METHODS

We measured PlGF and sFlt-1 in maternal serum samples from each trimester.

MAIN OUTCOME MEASURES

Odds ratios of preeclampsia subtypes by tertile categories of PlGF and sFlt-1.

RESULTS

Low (lowest third) PlGF and sFlt-1 levels in the first trimester, and low (lowest third) increase in PlGF and strong (highest third) increase in sFlt-1 from first to second trimester were associated with increased risk of preterm preeclampsia, both with and without SGA offspring. For term preeclampsia with SGA offspring, the associations were similar to the findings for preterm preeclampsia. For term preeclampsia without SGA offspring, low increase in PlGF from first to second trimester and high sFlt-1 in the third trimester were associated with increased risk.

CONCLUSIONS

Low PlGF and high sFlt-1 levels in maternal circulation are associated with subsequent development of preeclampsia, regardless of whether fetal growth is affected or not. For term preeclampsia without fetal growth restriction, the imbalance in angiogenic factors seems to appear later in pregnancy than for preterm preeclampsia.

The influence of overweight and obesity on maternal soluble fms-like tyrosine kinase 1 and its relationship with leptin during pregnancy

We studied obesity-related differences in the relation of maternal levels of leptin to levels of soluble fms-like tyrosine kinase 1 (sFlt1), an antiangiogenic protein that influences placentation and risk of adverse pregnancy outcomes. In a prospective cohort of 286 gravidas, we measured maternal serum levels of sFlt1 and leptin at 5 time points across pregnancy. Analyses stratified on prepregnancy body mass index (<25 vs ≥25) were done using mixed linear models. The mean leptin concentrations were significantly higher in overweight/obese compared to normal-weight women, while mean sFlt1 levels in second and third trimester were significantly higher in normal weight compared to overweight/obese women. The relationship between sFlt1 and leptin differed between the 2 strata. After controlling for maternal weight, a 1 ng/mL increase in leptin was associated with an 19.4 pg/mL increase in sFlt1 (P = .01) in normal-weight women, while leptin was not associated with sFlt1 (β = 1.1, P = .75) in overweight/obese women. Such differences suggest that metabolic differences in overweight/obese women compared to their normal weight peers may differentially impact the physiologic changes during pregnancy.

Umbilical artery chemokine CCL16 is associated with preterm preeclampsia and fetal growth restriction

BACKGROUND

Cytokines and growth factors synthesized by placental trophoblasts are suggested to induce endothelial and vascular smooth muscle cell apoptosis and affect angiogenesis.

OBJECTIVE

To investigate cord blood and placental immunoproteins in order to find new clues on pathogenetic factors of preterm preeclampsia.

METHODS

Cord blood samples were collected on 163 consecutive preterm deliveries prior to 32 gestational weeks. Placental function, clinical risk factors and 107 umbilical artery immunoproteins were analyzed. Classification and regression trees analysis was used to detect associations between the immunoproteins, clinical parameters and preterm preeclampsia. Placental expression of the immunoproteins and their receptors were subsequently investigated.

RESULTS

Preeclampsia complicated 34% of the pregnancies in this preterm cohort. Umbilical artery CCL16, CCL24, and CCL23 were associated with preeclampsia, CCL16 showing the strongest relationship with an OR (95% CI) of 24.5 (5.4-112.0). High umbilical artery CCL16 was also characteristic to fetuses with severe growth restriction (<3rd percentile). CCL16, CCL24 and their receptors, CCR1 and CCR3 were expressed in preeclamptic placentas.

CONCLUSIONS

High umbilical artery CCL16 is prominently detected in preterm preeclamptic pregnancies with severe growth restriction. A link to compensatory proangiogenic mechanisms has to be considered.

Localization of C-Fos-Induced Growth Factor (Figf) mRNA Expression in the Mouse Uterus during Implantation

The purpose of this study was to characterize the localization of Figf mRNA in the mouse uterus during embryo implantation. Strong Figf mRNA hybridization signals were seen in the primary decidual zone just after the onset of implantation from Days 4.5–6.5. On Day 7.5, this expression continued around the concept us, but in addition we observed high expression of Figf mRNA in the endothelial cells that line the forming vascular sinusoids in the lateral me some trial decidua. Interestingly, on Days 8.5 this high expression continued in the endothelial cells of sinusoids in the lateral me some trial decidual tissue but not in the decidual cells surrounding the concept us. As implantation and placental development finished, Figf mRNA expression remained in the endothelial cells of the sinusoids and spiral arterioles of the decidua basalis. Interestingly, Flt4 mRNA was localized to the endothelial cells lining the sinusoids that form during implantation. Since the endothelial cells of the me some trial sinusoids exhibit a high level of proliferation, we speculate that FIGF-FLT4 signaling may play a role in their formation and function during implantation. This work will provide a basis for further research on the potential role of FIGF-FLT4 signaling in endometrial angiogenesis during implantation in mice.

First trimester serum angiogenic/anti-angiogenic status in twin pregnancies: relationship with assisted reproduction technology

BACKGROUND

The risk of pre-eclampsia (PE) increases in twin pregnancies, especially when assisted reproduction technologies (ART) are used. The aim of this study was to assess angiogenic/anti-angiogenic factors in maternal serum in the first trimester of twin pregnancies and establish if the mode of conception influences angiogenic status.

METHODS

This prospective study enrolled women with twin (n = 61) and singleton (n = 50) pregnancies. Dichorionic twin pregnancies were divided into two groups according to their mode of conception. Singleton pregnancies were used as the control group. Soluble fms-like tyrosine kinase (sFlt-1), free placental growth factor (PlGF) and soluble endoglin (sEng) concentrations were measured in the first trimester maternal serum.

RESULTS

In the first trimester, women with twin pregnancies had higher serum concentrations of the anti-angiogenic factor sFlt-1 than that with singleton pregnancies (3924 ± 250 versus 2426 ± 162 pg/ml, respectively; P < 0.001). Maternal serum PlGF concentrations were lower in singleton pregnancies than those in twin pregnancies (37 ± 3.7 versus 59 ± 5.6, respectively; P < 0.001). Serum concentrations of sFlt-1 were higher in twin pregnancies conceived by ART than those in spontaneous twin pregnancies (4313 ± 389 versus 3522 ± 300 pg/ml, respectively; P < 0.05). No differences between groups were observed for sEng.

CONCLUSIONS

In the first trimester, twin pregnancies conceived using ART showed a heightened anti-angiogenic status that could explain the increased risk of PE in these cases.

Identification of cis- and trans-acting genetic variants explaining up to half the variation in circulating vascular endothelial growth factor levels

RATIONALE

Vascular endothelial growth factor (VEGF) affects angiogenesis, atherosclerosis, and cancer. Although the heritability of circulating VEGF levels is high, little is known about its genetic underpinnings.

OBJECTIVE

Our aim was to identify genetic variants associated with circulating VEGF levels, using an unbiased genome-wide approach, and to explore their functional significance with gene expression and pathway analysis.

METHODS AND RESULTS

We undertook a genome-wide association study of serum VEGF levels in 3527 participants of the Framingham Heart Study, with preplanned replication in 1727 participants from 2 independent samples, the STANISLAS Family Study and the Prospective Investigation of the Vasculature in Uppsala Seniors study. One hundred forty single nucleotide polymorphism (SNPs) reached genome-wide significance (P<5×10(-8)). We found evidence of replication for the most significant associations in both replication datasets. In a conditional genome-wide association study, 4 SNPs mapping to 3 chromosomal regions were independently associated with circulating VEGF levels: rs6921438 and rs4416670 (6p21.1, P=6.11×10(-506) and P=1.47×10(-12)), rs6993770 (8q23.1, P=2.50×10(-16)), and rs10738760 (9p24.2, P=1.96×10(-34)). A genetic score including these 4 SNPs explained 48% of the heritability of serum VEGF levels. Six of the SNPs that reached genome-wide significance in the genome-wide association study were significantly associated with VEGF messenger RNA levels in peripheral blood mononuclear cells. Ingenuity pathway analyses showed found plausible biological links between VEGF and 2 novel genes in these loci (ZFPM2 and VLDLR).

CONCLUSIONS

Genetic variants explaining up to half the heritability of serum VEGF levels were identified. These new insights provide important clues to the pathways regulating circulating VEGF levels.

miRNA expression profiling in formalin-fixed and paraffin-embedded placental tissue samples from pregnancies with severe preeclampsia

AIMS

Micro RNAs (miRNAs) are small, single-strand RNAs, playing an important role in post-transcriptional gene regulation. The placenta is considered to play a key role in pathogenesis of preeclampsia. The purpose of this study was to demonstrate deregulation of miRNAs in placentas with preeclampsia using formalin-fixed and paraffin-embedded (FFPE) tissues.

METHODS

Expression levels of 162 miRNAs were measured in FFPE placental tissues (5 with severe preeclampsia, 5 from a control group) using a quantitative qPCR based technique.

RESULTS

Six miRNAs were more than 2-fold over-expressed in severe preeclampsia: let-7b, miRNA-302*, miRNA-104, miRNA-128a, miRNA-182* and miRNA-133b. Gene ontology analyses were performed using the algorithms "TargetScanS", "microRNA", and "PicTar".

CONCLUSIONS

Two of the up-regulated miRNAs (miRNA-182* and miRNA-133b) are putative regulators of the transcript variants 1 and 2 of the BCL2-like gene, which controls apoptosis. miRNA-182* is also a probable angiogenesis regulator via angiogenin and VEGF-B. Apoptosis and angiogenesis are major mechanisms presumed to be involved in the pathogenesis of preeclampsia. Moreover, usability of qPCR technique based miRNA profiling for FFPE tissues was proofed. Hence FFPE tissue is the most widely used material for retrospective clinical studies, this method has a great property for future investigations in placenta research.

Angiogenic factors in maternal circulation and the risk of severe fetal growth restriction

Maternal angiogenic factors (placental growth factor, soluble fms-like tyrosine kinase 1 (Flt-1), and soluble endoglin) may be associated with fetal growth restriction, and the associations may differ according to stage of pregnancy. Among children born to pregnant women without preeclampsia in Norway between 1992 and 1994, 217 singletons with severe growth restriction (small for gestational age (SGA), <2.5th percentile) were compared with 378 singleton controls. For each angiogenic factor, SGA risk was related to concentrations in maternal serum collected in the first 2 trimesters, by using women with a serum concentration in the middle third at both samplings as reference. A low placental growth factor (lowest third) at both samplings was associated with high risk of SGA (odds ratio=3.8, 95% confidence interval: 1.6, 8.8). An increase from the lowest to the highest third of soluble Flt-1 was associated with high SGA risk (odds ratio=6.2, 95% confidence interval: 2.4, 16.1). Women with high soluble endoglin (highest third) at the second sampling had approximately a 3.5-fold increased risk of SGA. Low maternal soluble Flt-1 in early pregnancy followed by a strong subsequent increase in soluble Flt-1 and soluble endoglin was associated with a particularly high risk of severe fetal growth restriction.

Circulating angiogenic and antiangiogenic factors in women with eclampsia

OBJECTIVE

The objective of the study was to determine whether eclampsia has a different circulating profile of angiogenic (placental growth factor [PlGF]) and antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 [sVEGFR-1] and soluble endoglin [sEng]) from severe preeclampsia.

STUDY DESIGN

This cross-sectional study included pregnant women in the following groups: (1) normal pregnancy (n = 40); (2) severe preeclampsia (n = 40); and (3) eclampsia (n = 20). Maternal serum PlGF, sVEGFR-1, and sEng concentrations were determined using an enzyme-linked immunosorbent assay.

RESULTS

The study results included the following: (1) the median concentration of sVEGFR-1 and sEng was higher and of PlGF was lower in severe preeclampsia or eclampsia than in normal pregnancy (P < .001 for all); and (2) the median concentrations of these 3 analytes did not differ significantly between patients with severe preeclampsia and those with eclampsia.

CONCLUSION

Eclampsia is associated with higher maternal circulating concentrations of sVEGFR-1 and sEng and lower concentrations of PlGF than normal pregnancy but with similar concentrations to severe preeclampsia. These findings suggest that eclampsia shares a common pathogenic pathway as severe preeclampsia.