Serum Levels of Macrophage Colony Stimulating, Vascular Endothelial, and Placenta Growth Factor in Relation to Later Clinical Onset of Pre-Eclampsia and a Small-for-Gestational Age Birth

Human placenta-based genome-wide mRNA sequencing to identify TEK/IGF1/CSF1/ANGPT2 as crucial segments in the pathogenesis of pre-eclampsia

Pre-eclampsia is a pregnancy-specific disease commonly occurring in late pregnancy and has always been threatening maternal and fetal lives, yet the etiology and pathogenesis of pre-eclampsia are still uncertain. To depict the overall changes of genes at the genome-wide level and identify potential biomarkers for early diagnosis of pre-eclampsia, we conducted this study by collecting placenta samples donated by six pregnancy women, among whom three healthy women were included as controls and three women were diagnosed with pre-eclampsia. The placental sample tissues were then subjected to high-throughput sequencing. Furthermore, we proceeded with bioinformatics analysis and formulated the hypothesis of pre-eclampsia development and verified the potential targets of pre-eclampsia by immunohistochemistry. Demographically, we found that the baseline characteristics of study subjects were highly homogeneous except for gestational weeks and blood pressure, where the blood pressure was higher and gestational weeks were shorter in the pre-eclampsia group (systolic blood pressure 123.33 ± 4.62 vs. 148.67 ± 3.79 mmHg, p = 0.046; diastolic blood pressure 79.00 ± 5.20 vs. 88.33 ± 2.89 mmHg, p = 0.068; gestational weeks 39.33 ± 1.03 vs. 35.76 ± 2.41, p = 0.050). Specific pathological changes were identified, shown as syncytial knots, fibrinoid necrosis, perivillous fibrin deposition, and vasculitis. For high-throughput sequencing, a total of 1,891 dysregulated genes were determined, of which 960 genes were downregulated and 931 genes were upregulated. The bioinformatics analysis indicated that these genes, with different molecular functions in different parts of cells, were primarily responsible for endothelium development and vascular process in the circulatory system, and more than 10 signaling pathways were involved. By focusing on the PI3K-Akt signaling pathway, Rap1 signaling pathway, and disease enrichment analysis item pre-eclampsia, TEK, CSF1, IGF1, and ANGPT2 were identified to promote the development of pre-eclampsia. After confirming the placental expression of these genes at the protein level, we proposed the pathogenesis of pre-eclampsia as follows: the downregulation of TEK, CSF1, IGF1, and ANGPT2 may inhibit trophoblast proliferation and affect the remodeling of spiral arteries, causing maternal and fetal malperfusion and impeding nutrient exchange, thereby leading to clinical manifestations of pre-eclampsia.

Interventions for placental insufficiency and fetal growth restriction

Pregnancy complications adversely impact both mother and/or fetus throughout the lifespan. Fetal growth restriction (FGR) occurs when a fetus fails to reach their intrauterine potential for growth, it is the second highest leading cause of infant mortality, and leads to increased risk of developing non-communicable diseases in later life due 'fetal programming'. Abnormal placental development, growth and/or function underlies approximately 75% of FGR cases and there is currently no treatment save delivery, often prematurely. We previously demonstrated in a murine model of FGR that nanoparticle mediated, intra-placental human IGF-1 gene therapy maintains normal fetal growth. Multiple models of FGR currently exist reflecting the etiologies of human FGR and have been used by us and others to investigate the development of in utero therapeutics as discussed here. In addition to the in vivo models discussed herein, utilizing human models including in vitro (Choriocarcinoma cell lines and primary trophoblasts) and ex vivo (term villous fragments and placenta cotyledon perfusion) we have demonstrated robust nanoparticle uptake, transgene expression, nutrient transporter regulation without transfer to the fetus. For translational gene therapy application in the human placenta, there are multiple avenues that require investigation including syncytial uptake from the maternal circulation, transgene expression, functionality and longevity of treatment, impact of treatment on the mother and developing fetus. The potential impact of treating the placenta during gestation is high, wide-ranging across pregnancy complications, and may offer reduced risk of developing associated cardio-metabolic diseases in later life impacting at both an individual and societal level.

Association of endocannabinoids with pain in endometriosis

ABSTRACT

Endocannabinoid (eCB) levels fluctuate in inflammatory conditions and as such may take part in endometriosis-associated pain or even in endometriosis pathogenesis. In this case-control (23 cases and 19 controls) study, targeted lipids were measured in the serum and peritoneal fluid collected during laparoscopy. Endometriosis was confirmed histologically. Dysmenorrhea, abdominal pain, and dyspareunia were assessed using the Numeric Rating Scale for pain. Steroids, eCBs, and related lipids were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Tumor necrosis factor alpha, IL-8, PAPP-A, PP14, RANTES, OPG, MIDKINE, MCP-1, VEGF, leptin, and defensins were quantified by ELISA. We found that eCB levels were significantly influenced by both noncyclic and cyclic abdominal pain. Specifically, women suffering from noncyclic abdominal pain were characterized by a higher 2-AG level in the peritoneal fluid throughout the menstrual cycle, whereas women suffering from dysmenorrhea had higher 2-AG levels and lower AEA levels during the proliferative phase alone. In addition, 2-AG positively correlated with prostaglandin E2 (PGE2), and the ratio AEA/2-AG positively correlated with defensins, suggesting a possible link between endocannabinoids system and inflammatory pain. The results of the current study indicate that the eCB system may play a role in endometriosis-associated pain, but additional studies are needed to investigate the causal relationship.

Identification of miR-210-5p in human placentae from pregnancies complicated by preeclampsia and intrauterine growth restriction, and its potential role in the pregnancy complications

Preeclampsia (PE) and intrauterine growth restriction (IUGR) are pregnancy complications resulting from abnormal placental development. As epigenetic regulators, microRNAs can regulate placental development and contribute to the disease pathophysiology by influencing the expression of genes involved in placental development or disease. Our previous study revealed an increase in miR-210-5p expression in placentae from patients with early-onset pregnancy complications and identified candidate gene targets for miR-210-5p. The purpose of this study was to: (i) validate candidate gene targets predicted for miR-210-5p from microRNA-RNA expression data, and (ii) overexpress miR-210-5p in a trophoblast cell line (HTR-8/SVneo) to assess impact on trophoblast cell functions. Integration of the miRNA and RNA sequencing expression data revealed 8 candidate gene targets for miR-210-5p in patients with PE only or PE + IUGR. Luciferase reporter assays identified two gene targets for miR-210-5p, CSF1 and ITGAM. Real-time PCR confirmed the decreased expression of CSF1 and ITGAM in patients with PE + IUGR. Immunohistochemistry of placentae from late second trimester identified CSF1 and ITGAM in intermediate trophoblast cells in the decidua. Expression levels of CSF1 and ITGAM were reduced in HTR-8/SVneo cells following increased miR-210-5p expression. Concomitantly, HTR-8/SVneo cells demonstrate an average 45% reduction in cell migration. These findings suggest that miR-210-5p may contribute to dysfunction of intermediate trophoblasts and potentially contribute to the disease process of these pregnancy complications.

Biochemical tests of placental function versus ultrasound assessment of fetal size for stillbirth and small-for-gestational-age infants

BACKGROUND

Stillbirth affects 2.6 million pregnancies worldwide each year. Whilst the majority of cases occur in low- and middle-income countries, stillbirth remains an important clinical issue for high-income countries (HICs) - with both the UK and the USA reporting rates above the mean for HICs. In HICs, the most frequently reported association with stillbirth is placental dysfunction. Placental dysfunction may be evident clinically as fetal growth restriction (FGR) and small-for-dates infants. It can be caused by placental abruption or hypertensive disorders of pregnancy and many other disorders and factorsPlacental abnormalities are noted in 11% to 65% of stillbirths. Identification of FGA is difficult in utero. Small-for-gestational age (SGA), as assessed after birth, is the most commonly used surrogate measure for this outcome. The degree of SGA is associated with the likelihood of FGR; 30% of infants with a birthweight < 10th centile are thought to be FGR, while 70% of infants with a birthweight < 3rd centile are thought to be FGR. Critically, SGA is the most significant antenatal risk factor for a stillborn infant. Correct identification of SGA infants is associated with a reduction in the perinatal mortality rate. However, currently used tests, such as measurement of symphysis-fundal height, have a low reported sensitivity and specificity for the identification of SGA infants.

OBJECTIVES

The primary objective was to assess and compare the diagnostic accuracy of ultrasound assessment of fetal growth by estimated fetal weight (EFW) and placental biomarkers alone and in any combination used after 24 weeks of pregnancy in the identification of placental dysfunction as evidenced by either stillbirth, or birth of a SGA infant. Secondary objectives were to investigate the effect of clinical and methodological factors on test performance.

SEARCH METHODS

We developed full search strategies with no language or date restrictions. The following sources were searched: MEDLINE, MEDLINE In Process and Embase via Ovid, Cochrane (Wiley) CENTRAL, Science Citation Index (Web of Science), CINAHL (EBSCO) with search strategies adapted for each database as required; ISRCTN Registry, UK Clinical Trials Gateway, WHO International Clinical Trials Portal and ClinicalTrials.gov for ongoing studies; specialist abstract and conference proceeding resources (British Library's ZETOC and Web of Science Conference Proceedings Citation Index). Search last conducted in Ocober 2016.

SELECTION CRITERIA

We included studies of pregnant women of any age with a gestation of at least 24 weeks if relevant outcomes of pregnancy (live birth/stillbirth; SGA infant) were assessed. Studies were included irrespective of whether pregnant women were deemed to be low or high risk for complications or were of mixed populations (low and high risk). Pregnancies complicated by fetal abnormalities and multi-fetal pregnancies were excluded as they have a higher risk of stillbirth from non-placental causes. With regard to biochemical tests, we included assays performed using any technique and at any threshold used to determine test positivity.

DATA COLLECTION AND ANALYSIS

We extracted the numbers of true positive, false positive, false negative, and true negative test results from each study. We assessed risk of bias and applicability using the QUADAS-2 tool. Meta-analyses were performed using the hierarchical summary ROC model to estimate and compare test accuracy.

MAIN RESULTS

We included 91 studies that evaluated seven tests - blood tests for human placental lactogen (hPL), oestriol, placental growth factor (PlGF) and uric acid, ultrasound EFW and placental grading and urinary oestriol - in a total of 175,426 pregnant women, in which 15,471 pregnancies ended in the birth of a small baby and 740 pregnancies which ended in stillbirth. The quality of included studies was variable with most domains at low risk of bias although 59% of studies were deemed to be of unclear risk of bias for the reference standard domain. Fifty-three per cent of studies were of high concern for applicability due to inclusion of only high- or low-risk women.Using all available data for SGA (86 studies; 159,490 pregnancies involving 15,471 SGA infants), there was evidence of a difference in accuracy (P < 0.0001) between the seven tests for detecting pregnancies that are SGA at birth. Ultrasound EFW was the most accurate test for detecting SGA at birth with a diagnostic odds ratio (DOR) of 21.3 (95% CI 13.1 to 34.6); hPL was the most accurate biochemical test with a DOR of 4.78 (95% CI 3.21 to 7.13). In a hypothetical cohort of 1000 pregnant women, at the median specificity of 0.88 and median prevalence of 19%, EFW, hPL, oestriol, urinary oestriol, uric acid, PlGF and placental grading will miss 50 (95% CI 32 to 68), 116 (97 to 133), 124 (108 to 137), 127 (95 to 152), 139 (118 to 154), 144 (118 to 161), and 144 (122 to 161) SGA infants, respectively. For the detection of pregnancies ending in stillbirth (21 studies; 100,687 pregnancies involving 740 stillbirths), in an indirect comparison of the four biochemical tests, PlGF was the most accurate test with a DOR of 49.2 (95% CI 12.7 to 191). In a hypothetical cohort of 1000 pregnant women, at the median specificity of 0.78 and median prevalence of 1.7%, PlGF, hPL, urinary oestriol and uric acid will miss 2 (95% CI 0 to 4), 4 (2 to 8), 6 (6 to 7) and 8 (3 to 13) stillbirths, respectively. No studies assessed the accuracy of ultrasound EFW for detection of pregnancy ending in stillbirth.

AUTHORS' CONCLUSIONS

Biochemical markers of placental dysfunction used alone have insufficient accuracy to identify pregnancies ending in SGA or stillbirth. Studies combining U and placental biomarkers are needed to determine whether this approach improves diagnostic accuracy over the use of ultrasound estimation of fetal size or biochemical markers of placental dysfunction used alone. Many of the studies included in this review were carried out between 1974 and 2016. Studies of placental substances were mostly carried out before 1991 and after 2013; earlier studies may not reflect developments in test technology.

Perinatal and long-term effects of maternal uterine artery adenoviral VEGF-A165 gene therapy in the growth-restricted guinea pig fetus

Uterine artery application of adenoviral vascular endothelial growth factor A₁₆₅ (Ad.VEGF-A₁₆₅) gene therapy increases uterine blood flow and fetal growth in experimental animals with fetal growth restriction (FGR). Whether Ad.VEGF-A₁₆₅ reduces lifelong cardiovascular disease risk imposed by FGR remains unknown. Here, pregnant guinea pigs fed 70% normal food intake to induce FGR received Ad.VEGF-A₁₆₅ (1×10¹⁰ viral particles, n = 15) or vehicle ( n = 10), delivered to the external surface of the uterine arteries, in midpregnancy. Ad libitum-fed controls received vehicle only ( n = 14). Litter size, gestation length, and perinatal mortality were similar in control, untreated FGR, and FGR+Ad.VEGF-A₁₆₅ animals. When compared with controls, birth weight was lower in male but higher in female pups following maternal nutrient restriction, whereas both male and female FGR+Ad.VEGF-A₁₆₅ pups were heavier than untreated FGR pups ( P < 0.05, ANOVA). Postnatal weight gain was 10-20% greater in female FGR+Ad.VEGF-A₁₆₅ than in untreated FGR pups, depending on age, although neither group differed from controls. Maternal nutrient restriction reduced heart weight in adult female offspring irrespective of Ad.VEGF-A₁₆₅ treatment but did not alter ventricular wall thickness. In males, postnatal weight gain and heart morphology were not affected by maternal treatment. Neither systolic, diastolic, mean arterial pressure, adrenal weight, nor basal or challenged plasma cortisol were affected by maternal undernutrition or Ad.VEGF-A₁₆₅ in either sex. Therefore, increased fetal growth conferred by maternal uterine artery Ad.VEGF-A₁₆₅ is sustained postnatally in FGR female guinea pigs. In this study, we did not find evidence for an effect of maternal nutrient restriction or Ad.VEGF-A₁₆₅ therapy on adult offspring blood pressure.

Predicting delivery of a small-for-gestational-age infant and adverse perinatal outcome in women with suspected pre-eclampsia

OBJECTIVE

To evaluate the test performance of 47 biomarkers and ultrasound parameters for the prediction of delivery of a small-for-gestational-age (SGA) infant and adverse perinatal outcome in women presenting with suspected pre-eclampsia.

METHODS

This was a prospective, multicenter observational study in which 47 biomarkers and ultrasound parameters were measured in 397 women with a singleton pregnancy presenting with suspected preterm pre-eclampsia between 20 + 0 and 36 + 6 weeks' gestation, with the objective of evaluating them as predictors of subsequent delivery of a SGA infant and adverse perinatal outcome. Women with confirmed pre-eclampsia at enrollment were excluded. Factor analysis and stepwise logistic regression were performed in two prespecified groups stratified according to gestational age at enrollment. The primary outcome was delivery of a SGA infant with a birth weight < 3^rd customized centile (SGA-3), and secondary outcomes were a SGA infant with a birth weight < 10^th customized centile and adverse perinatal outcome.

RESULTS

In 274 women presenting at 20 + 0 to 34 + 6 weeks' gestation, 96 (35%) delivered a SGA-3 infant. For prediction of SGA-3, low maternal placental growth factor (PlGF) concentration had a sensitivity of 93% (95% CI, 84-98%) and negative predictive value (NPV) of 90% (95% CI, 76-97%) compared with a sensitivity of 71% (95% CI, 58-82%) and a NPV of 79% (95% CI, 68-87%) for ultrasound parameters (estimated fetal weight or abdominal circumference < 10^th centile). No individual biomarker evaluated had a better performance than did PlGF, and marker combinations made only small improvements to the test performance. Similar results were found in 123 women presenting between 35 + 0 and 36 + 6 weeks' gestation.

CONCLUSION

In women presenting with suspected preterm pre-eclampsia, measurement of PlGF offers a useful adjunct for identifying those at high risk of delivering a SGA infant, allowing appropriate surveillance and timely intervention. © 2017 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Placental growth factor (alone or in combination with soluble fms-like tyrosine kinase 1) as an aid to the assessment of women with suspected pre-eclampsia: systematic review and economic analysis

BACKGROUND

Pre-eclampsia (PE) prediction based on blood pressure, presence of protein in the urine, symptoms and laboratory test abnormalities can result in false-positive diagnoses. This may lead to unnecessary antenatal admissions and preterm delivery. Blood tests that measure placental growth factor (PlGF) or the ratio of soluble fms-like tyrosine kinase 1 (sFlt-1) to PlGF could aid prediction of PE if either were added to routine clinical assessment or used as a replacement for proteinuria testing.

OBJECTIVES

To evaluate the diagnostic accuracy and cost-effectiveness of PlGF-based tests for patients referred to secondary care with suspected PE in weeks 20-37 of pregnancy.

DESIGN

Systematic reviews and an economic analysis.

DATA SOURCES

Bibliographic databases including MEDLINE, EMBASE, Web of Science and The Cochrane Library and Database of Abstracts of Reviews of Effects were searched up to July 2015 for English-language references. Conferences, websites, systematic reviews and confidential company submissions were also accessed.

REVIEW METHODS

Systematic reviews of test accuracy and economic studies were conducted to inform an economic analysis. Test accuracy studies were required to include women with suspected PE and report quantitatively the accuracy of PlGF-based tests; their risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria. The economic studies review had broad eligibility criteria to capture any types of economic analysis; critical appraisal employed standard checklists consistent with National Institute for Health and Care Excellence criteria. Study selection, critical appraisal and data extraction in both reviews were performed by two reviewers.

ECONOMIC ANALYSIS

An independent economic analysis was conducted based on a decision tree model, using the best evidence available. The model evaluates costs (2014, GBP) from a NHS and Personal Social Services perspective. Given the short analysis time horizon, no discounting was undertaken.

RESULTS

Four studies were included in the systematic review of test accuracy: two on Alere's Triage^® PlGF test (Alere, Inc., San Diego, CA, USA) for predicting PE requiring delivery within a specified time and two on Roche Diagnostics' Elecsys^® sFlt-1 to PlGF ratio test (Roche Diagnostics GmbH, Mannheim, Germany) for predicting PE within a specified time. Three studies were included in the systematic review of economic studies, and two confidential company economic analyses were assessed separately. Study heterogeneity precluded meta-analyses of test accuracy or cost-analysis outcomes, so narrative syntheses were conducted to inform the independent economic model. The model predicts that, when supplementing routine clinical assessment for rule-out and rule-in of PE, the two tests would be cost-saving in weeks 20-35 of gestation, and marginally cost-saving in weeks 35-37, but with minuscule impact on quality of life. Length of neonatal intensive care unit stay was the most influential parameter in sensitivity analyses. All other sensitivity analyses had negligible effects on results.

LIMITATIONS

No head-to-head comparisons of the tests were identified. No studies investigated accuracy of PlGF-based tests when used as a replacement for proteinuria testing. Test accuracy studies were found to be at high risk of clinical review bias.

CONCLUSIONS

The Triage and Elecsys tests would save money if added to routine clinical assessment for PE. The magnitude of savings is uncertain, but the tests remain cost-saving under worst-case assumptions. Further research is required to clarify how the test results would be interpreted and applied in clinical practice.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015017670.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Screening for fetal growth restriction using fetal biometry combined with maternal biomarkers

Fetal growth restriction is a major determinant of perinatal morbidity and mortality. Screening for fetal growth restriction is a key element of prenatal care but it is recognized to be problematic. Screening using clinical risk assessment and targeting ultrasound to high-risk women is the standard of care in the United States and United Kingdom, but the approach is known to have low sensitivity. Systematic reviews of randomized controlled trials do not demonstrate any benefit from universal ultrasound screening for fetal growth restriction in the third trimester, but the evidence base is not strong. Implementation of universal ultrasound screening in low-risk women in France failed to reduce the risk of complications among small-for-gestational-age infants but did appear to cause iatrogenic harm to false positives. One strategy to making progress is to improve screening by developing more sensitive and specific tests with the key goal of differentiating between healthy small fetuses and those that are small through fetal growth restriction. As abnormal placentation is thought to be the major cause of fetal growth restriction, one approach is to combine fetal biometry with an indicator of placental dysfunction. In the past, these indicators were generally ultrasonic measurements, such as Doppler flow velocimetry of the uteroplacental circulation. However, another promising approach is to combine ultrasonic suspicion of small-for-gestational-age infant with a blood test indicating placental dysfunction. Thus far, much of the research on maternal serum biomarkers for fetal growth restriction has involved the secondary analysis of tests performed for other indications, such as fetal aneuploidies. An exemplar of this is pregnancy-associated plasma protein A. This blood test is performed primarily to assess the risk of Down syndrome, but women with low first-trimester levels are now serially scanned in later pregnancy due to associations with placental causes of stillbirth, including fetal growth restriction. The development of "omic" technologies presents a huge opportunity to identify novel biomarkers for fetal growth restriction. The hope is that when such markers are measured alongside ultrasonic fetal biometry, the combination would have strong predictive power for fetal growth restriction and its related complications. However, a series of important methodological considerations in assessing the diagnostic effectiveness of new tests will have to be addressed. The challenge thereafter will be to identify novel disease-modifying interventions, which are the essential partner to an effective screening test to achieve clinically effective population-based screening.

EVERREST prospective study: a 6-year prospective study to define the clinical and biological characteristics of pregnancies affected by severe early onset fetal growth restriction

BACKGROUND

Fetal growth restriction (FGR) is a serious obstetric condition for which there is currently no treatment. The EVERREST Prospective Study has been designed to characterise the natural history of pregnancies affected by severe early onset FGR and establish a well phenotyped bio-bank. The findings will provide up-to-date information for clinicians and patients and inform the design and conduct of the EVERREST Clinical Trial: a phase I/IIa trial to assess the safety and efficacy of maternal vascular endothelial growth factor (VEGF) gene therapy in severe early onset FGR. Data and samples from the EVERREST Prospective Study will be used to identify ultrasound and/or biochemical markers of prognosis in pregnancies with an estimated fetal weight (EFW) <3rd centile between 20+0 and 26+6 weeks of gestation.

METHODS

This is a 6 year European multicentre prospective cohort study, recruiting women with a singleton pregnancy where the EFW is <3rd centile for gestational age and <600 g at 20+0 to 26+6 weeks of gestation. Detailed data are collected on: maternal history; antenatal, peripartum, and postnatal maternal complications; health economic impact; psychological impact; neonatal condition, progress and complications; and infant growth and neurodevelopment to 2 years of corrected age in surviving infants. Standardised longitudinal ultrasound measurements are performed, including: fetal biometry; uterine artery, umbilical artery, middle cerebral artery, and ductus venosus Doppler velocimetry; and uterine artery and umbilical vein volume blood flow. Samples of maternal blood and urine, amniotic fluid (if amniocentesis performed), placenta, umbilical cord blood, and placental bed (if caesarean delivery performed) are collected for bio-banking. An initial analysis of maternal blood samples at enrolment is planned to identify biochemical markers that are predictors for fetal or neonatal death.

DISCUSSION

The findings of the EVERREST Prospective Study will support the development of a novel therapy for severe early onset FGR by describing in detail the natural history of the disease and by identifying women whose pregnancies have the poorest outcomes, in whom a therapy might be most advantageous. The findings will also enable better counselling of couples with affected pregnancies, and provide a valuable resource for future research into the causes of FGR.

TRIAL REGISTRATION

NCT02097667 registered 31^st October 2013.

EVERREST prospective study: a 6-year prospective study to define the clinical and biological characteristics of pregnancies affected by severe early onset fetal growth restriction

Background

Fetal growth restriction (FGR) is a serious obstetric condition for which there is currently no treatment. The EVERREST Prospective Study has been designed to characterise the natural history of pregnancies affected by severe early onset FGR and establish a well phenotyped bio-bank. The findings will provide up-to-date information for clinicians and patients and inform the design and conduct of the EVERREST Clinical Trial: a phase I/IIa trial to assess the safety and efficacy of maternal vascular endothelial growth factor (VEGF) gene therapy in severe early onset FGR. Data and samples from the EVERREST Prospective Study will be used to identify ultrasound and/or biochemical markers of prognosis in pregnancies with an estimated fetal weight (EFW) <3rd centile between 20+0 and 26+6 weeks of gestation.

Methods

This is a 6 year European multicentre prospective cohort study, recruiting women with a singleton pregnancy where the EFW is <3rd centile for gestational age and <600 g at 20+0 to 26+6 weeks of gestation. Detailed data are collected on: maternal history; antenatal, peripartum, and postnatal maternal complications; health economic impact; psychological impact; neonatal condition, progress and complications; and infant growth and neurodevelopment to 2 years of corrected age in surviving infants. Standardised longitudinal ultrasound measurements are performed, including: fetal biometry; uterine artery, umbilical artery, middle cerebral artery, and ductus venosus Doppler velocimetry; and uterine artery and umbilical vein volume blood flow. Samples of maternal blood and urine, amniotic fluid (if amniocentesis performed), placenta, umbilical cord blood, and placental bed (if caesarean delivery performed) are collected for bio-banking. An initial analysis of maternal blood samples at enrolment is planned to identify biochemical markers that are predictors for fetal or neonatal death.

Discussion

The findings of the EVERREST Prospective Study will support the development of a novel therapy for severe early onset FGR by describing in detail the natural history of the disease and by identifying women whose pregnancies have the poorest outcomes, in whom a therapy might be most advantageous. The findings will also enable better counselling of couples with affected pregnancies, and provide a valuable resource for future research into the causes of FGR.

Trial registration

NCT02097667 registered 31^st October 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-017-1226-7) contains supplementary material, which is available to authorized users.

Maternal Therapy with Ad.VEGF-A165 Increases Fetal Weight at Term in a Guinea-Pig Model of Fetal Growth Restriction

In a model of growth-restricted sheep pregnancy, it was previously demonstrated that transient uterine artery VEGF overexpression can improve fetal growth. This approach was tested in guinea-pig pregnancies, where placental physiology is more similar to humans. Fetal growth restriction (FGR) was attained through peri-conceptual nutrient restriction in virgin guinea pigs. Ad.VEGF-A₁₆₅ or Ad.LacZ (1 × 10¹⁰vp) was applied at mid-gestation via laparotomy, delivered externally to the uterine circulation with thermosensitive gel. At short-term (3-8 days post surgery) or at term gestation, pups were weighed, and tissues were sampled for vector spread analysis, VEGF expression, and its downstream effects. Fetal weight at term was increased (88.01 ± 13.36 g; n = 26) in Ad.VEGF-A₁₆₅-treated animals compared with Ad.LacZ-treated animals (85.52 ± 13.00 g; n = 19; p = 0.028). The brain, liver, and lung weight and crown rump length were significantly larger in short-term analyses, as well as VEGF expression in transduced tissues. At term, molecular analyses confirmed the presence of VEGF transgene in target tissues but not in fetal samples. Tissue histology analysis and blood biochemistry/hematological examination were comparable with controls. Uterine artery relaxation in Ad.VEGF-A₁₆₅-treated dams was higher compared with Ad.LacZ-treated dams. Maternal uterine artery Ad.VEGF-A₁₆₅ increases fetal growth velocity and term fetal weight in growth-restricted guinea-pig pregnancy.

Assessment of angiogenesis modulators in pregnant women with pre-eclampsia: a case-control study

PURPOSE

This study aimed to evaluate the serum concentration of factors associated with placental angiogenesis in pre-eclamptic and normotensive pregnant women.

METHODS

This was a prospective, cross-sectional, case-control study in which the pro-angiogenic factors PlGF, VEGF and IL-10, and the anti-angiogenic factors IL-6, IL-17 and TNF-α of 55 pregnant women (31 with pre-eclampsia-PE and 24 normotensive), with gestational age ≥20 weeks, were measured in maternal blood through the enzyme-linked immunosorbent assay (ELISA). The Mann-Whitney and Kruskal-Wallis tests were used for comparison between groups.

RESULTS

Serum PIGF was reduced in the group of pregnant women with PE when compared with the normotensive women (493.2 ± 55.1 pg/mL vs. 4.4 ± 26.5 pg/mL; p < 0.001). There was no significant difference in PlGF levels in the pre-eclamptic pregnant women in relation to gestational age or proteinuria levels (p > 0.05). The serum levels of VEGF, IL-17, IL-10 and TNF-α were lower in the pregnant women with PE when compared with their normotensive peers, while the IL-6 levels were higher; however, this difference was not statistically significant (p > 0.05).

CONCLUSION

Serum PlGF levels were reduced in the pregnant women with PE and were unrelated to disease severity. Serum levels of VEGF, IL-17, IL-10 and TNF-α were reduced in the pre-eclamptic pregnant women when compared with their normotensive peers, without statistically significant differences.

Angiogenic and inflammatory biomarkers in midpregnancy and small-for-gestational-age outcomes in Tanzania

OBJECTIVE

We sought to investigate the relationship between a panel of angiogenic and inflammatory biomarkers measured in midpregnancy and small-for-gestational-age (SGA) outcomes in sub-Saharan Africa.

STUDY DESIGN

Concentrations of 18 angiogenic and inflammatory biomarkers were determined in 432 pregnant women in Dar es Salaam, Tanzania, who participated in a trial examining the effect of multivitamins on pregnancy outcomes. Infants falling below the 10th percentile of birthweight for gestational age relative to the applied growth standards were considered SGA. Multivariate binomial regression models with the log link function were used to determine the relative risk of SGA associated with increasing quartiles of each biomarker. Restricted cubic splines were used to test for nonlinearity of these associations.

RESULTS

A total of 60 participants (13.9%) gave birth to SGA infants. Compared to those in the first quartile, the risk of SGA was reduced among those in the fourth quartiles of vascular endothelial growth factor-A (adjusted risk ratio [RR], 0.38; 95% confidence interval [CI], 0.19-0.74), placental growth factor (adjusted RR, 0.28; 95% CI, 0.12-0.61), soluble fms-like tyrosine kinase-1 (adjusted RR, 0.48; 95% CI, 0.23-1.01), monocyte chemoattractant protein-1 (adjusted RR, 0.48; 95% CI, 0.25-0.92), and leptin (adjusted RR, 0.46; 95% CI, 0.22-0.96).

CONCLUSION

Our findings provide evidence of altered angiogenic and inflammatory mediators, at midpregnancy, in women who went on to deliver SGA infants.

The importance of early life in childhood obesity and related diseases: a report from the 2014 Gravida Strategic Summit

Obesity and its related non-communicable diseases (NCDs), such as type 2 diabetes, heart disease and cancer, impose huge burdens on society, particularly the healthcare system. Until recently, public health and policy were primarily focused on secondary prevention and treatment of NCDs. However, epidemiological and experimental evidence indicates that early-life exposures influence the risk of childhood obesity and related diseases later in life, and has now focused attention on the health of both mother and child. During pregnancy and the early neonatal period, individuals respond to their environment by establishing anatomical, physiological and biochemical trajectories that shape their future health. This period of developmental plasticity provides an early window of opportunity to mitigate the environmental insults that may increase an individual’s sensitivity to, or risk of, developing obesity or related diseases later in life. Although much investigation has already occurred in the area of Developmental Origins of Health and Disease research, the science itself is still in its infancy. It remains for researchers to tackle the important outstanding questions and translate their knowledge into workable solutions for the public good. The challenge, however, is to decide which areas to focus on. With these opportunities and challenges in mind, the 2014 Gravida Summit convened to examine how its early-life research program can determine which areas of research into mechanisms, biomarkers and interventions could contribute to the international research strategy to fight childhood obesity and its related diseases.

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.

Novel biomarkers for predicting intrauterine growth restriction: a systematic review and meta-analysis

BACKGROUND

Several biomarkers for predicting intrauterine growth restriction (IUGR) have been proposed in recent years. However, the predictive performance of these biomarkers has not been systematically evaluated.

OBJECTIVE

To determine the predictive accuracy of novel biomarkers for IUGR in women with singleton gestations.

SEARCH STRATEGY

Electronic databases, reference list checking and conference proceedings.

SELECTION CRITERIA

Observational studies that evaluated the accuracy of novel biomarkers proposed for predicting IUGR.

DATA COLLECTION AND ANALYSIS

Data were extracted on characteristics, quality and predictive accuracy from each study to construct 2×2 tables. Summary receiver operating characteristic curves, sensitivities, specificities and likelihood ratios (LRs) were generated.

MAIN RESULTS

A total of 53 studies, including 39,974 women and evaluating 37 novel biomarkers, fulfilled the inclusion criteria. Overall, the predictive accuracy of angiogenic factors for IUGR was minimal (median pooled positive and negative LRs of 1.7, range 1.0-19.8; and 0.8, range 0.0-1.0, respectively). Two small case-control studies reported high predictive values for placental growth factor and angiopoietin-2 only when IUGR was defined as birthweight centile with clinical or pathological evidence of fetal growth restriction. Biomarkers related to endothelial function/oxidative stress, placental protein/hormone, and others such as serum levels of vitamin D, urinary albumin:creatinine ratio, thyroid function tests and metabolomic profile had low predictive accuracy.

CONCLUSIONS

None of the novel biomarkers evaluated in this review are sufficiently accurate to recommend their use as predictors of IUGR in routine clinical practice. However, the use of biomarkers in combination with biophysical parameters and maternal characteristics could be more useful and merits further research.

Accuracy of circulating placental growth factor, vascular endothelial growth factor, soluble fms-like tyrosine kinase 1 and soluble endoglin in the prediction of pre-eclampsia: a systematic review and meta-analysis

BACKGROUND

Biomarkers have been proposed for identification of women at increased risk of developing pre-eclampsia.

OBJECTIVES

To investigate the capacity of circulating placental growth factor (PlGF), vascular endothelial growth factor (VEGF), soluble fms-like tyrosine kinase-1 (sFLT1) and soluble endoglin (sENG) to predict pre-eclampsia.

SEARCH STRATEGY

Medline and Embase through October 2010 and reference lists of reviews, without constraints.

SELECTION CRITERIA

We included original publications on testing of PlGF, VEGF, sFLT1 and sENG in serum or plasma of pregnant women at <30 weeks of gestation and before clinical onset of pre-eclampsia.

DATA COLLECTION AND ANALYSIS

Two reviewers independently identified eligible studies, extracted descriptive and test accuracy data and assessed methodological quality. Summary estimates of discriminatory performance were obtained.

MAIN RESULTS

We included 34 studies. Concentrations of PlGF (27 studies) and VEGF (three studies) were lower in women who developed pre-eclampsia: standardised mean differences (SMD) -0.56 (95% CI -0.77 to -0.35) and -1.25 (95% CI -2.73 to 0.23). Concentrations of sFLT1 (19 studies) and sENG (ten studies) were higher: SMD 0.48 (95% CI 0.21-0.75) and SMD 0.54 (95% CI 0.24-0.84). The summary diagnostic odds ratios were: PlGF 9.0 (95% CI 5.6-14.5), sFLT1 6.6 (95% CI 3.1-13.7), sENG 4.2 (95% CI 2.4-7.2), which correspond to sensitivities of 32%, 26% and 18%, respectively, for a 5% false-positive rate.

AUTHOR'S CONCLUSIONS

PlGF, sFLT1 and sENG showed modest but significantly different concentrations before 30 weeks of gestation in women who developed pre-eclampsia. Test accuracies of all four markers, however, are too poor for accurate prediction of pre-eclampsia in clinical practice.

An unexpected tail of VEGF and PlGF in pre-eclampsia

PET (pre-eclamptic toxaemia), characterized by pregnancy-related hypertension and proteinuria, due to widespread endothelial dysfunction, is a primary cause of maternal morbidity. Altered circulating factors, particularly the VEGF (vascular endothelial growth factor) family of proteins and their receptors, are thought to be key contributors to this disease. Plasma from patients with PET induces numerous cellular and physiological changes in endothelial cells, indicating the presence of a circulating imbalance of the normal plasma constituents. These have been narrowed down to macromolecules of the VEGF family of proteins and receptors. It has been shown that responses of endothelial cells in intact vessels to plasma from patients with pre-eclampsia is VEGF-dependent. It has recently been shown that this may be specific to the VEGF₁₆₅b isoform, and blocked by addition of recombinant human PlGF (placental growth factor). Taken together with results that show that sVEGFR1 (soluble VEGF receptor 1) levels are insufficient to bind VEGF-A in human plasma from patients with pre-eclampsia, and that other circulating macromolecules bind, but do not inactivate, VEGF-A, this suggests that novel hypotheses involving altered bioavailability of VEGF isoforms resulting from reduced or bound PlGF, or increased sVEGFR1 increasing biological activity of circulating plasma, could be tested. This suggests that knowing how to alter the balance of VEGF family members could prevent endothelial activation, and potentially some symptoms, of pre-eclampsia.

Coordinate regulation of tissue macrophage and dendritic cell population dynamics by CSF-1

CSF-1 drives the homeostatic expansion of macrophages within the growing myometrium of pregnant mice by stimulating in situ proliferation and inducing monocyte precursor recruitment from the blood.

Tissue macrophages (Mϕs) and dendritic cells (DCs) play essential roles in tissue homeostasis and immunity. How these cells are maintained at their characteristic densities in different tissues has remained unclear. Aided by a novel flow cytometric technique for assessing relative rates of blood-borne precursor recruitment, we examined Mϕ and DC population dynamics in the pregnant mouse uterus, where rapid tissue growth facilitated a dissection of underlying regulatory mechanisms. We demonstrate how Mϕ dynamics, and thus Mϕ tissue densities, are locally controlled by CSF-1, a pleiotropic growth factor whose in situ level of activity varied widely between uterine tissue layers. CSF-1 acted in part by inducing Mϕ proliferation and in part by stimulating the extravasation of Ly6C^hi monocytes (Mos) that served as Mϕ precursors. Mo recruitment was dependent on the production of CCR2 chemokine receptor ligands by uterine Mϕs in response to CSF-1. Unexpectedly, a parallel CSF-1–regulated, but CCR2-independent pathway influenced uterine DC tissue densities by controlling local pre-DC extravasation rates. Together, these data provide cellular and molecular insight into the regulation of Mϕ tissue densities under noninflammatory conditions and reveal a central role for CSF-1 in the coordination of Mϕ and DC homeostasis.

Increased endometrial placenta growth factor (PLGF) gene expression in women with successful implantation

OBJECTIVE

To analyze the vascularization of the endometrium via hysteroscopy and to assess its correlation with angiogenic factor gene expression and embryo implantation rate.

DESIGN

Cross-sectional study.

SETTING

Public university hospital.

PATIENT(S)

Patients undergoing hysteroscopy for supposed infertility.

INTERVENTION(S)

Endometrial quality assessment according to Sakumoto-Masamoto, performed in the early secretory phase of the cycle. Collection of an endometrial tissue biopsy.

MAIN OUTCOME MEASURE(S)

RNA extraction, reverse transcription, and determination of gene expression of angiogenesis- and implantation-relevant factors using quantitative polymerase chain reaction. Retrieval of pregnancy information from the medical records.

RESULT(S)

Good quantity/quality RNA with infertility history was obtained from 63 participating women. Those with a "good" endometrium and subsequent pregnancy showed increased gene expression for placenta growth factor when compared with patients with a "bad" endometrium and who did not succeed with pregnancy to date. Nonpregnant women with a "good" endometrium presented an intermediate result. No significant differences were observed for several other genes tested, but trends in the same direction were observed.

CONCLUSION(S)

This study demonstrates for the first time that endometrial PLGF expression corresponds to the hysteroscopic appearance of the endometrium, and therefore has potential as a clinically relevant prognosticator for infertility treatment success.

Metabolic profiling uncovers a phenotypic signature of small for gestational age in early pregnancy

Being born small for gestational age (SGA) confers increased risks of perinatal morbidity and mortality and increases the risk of cardiovascular complications and diabetes in later life. Accumulating evidence suggests that the etiology of SGA is usually associated with poor placental vascular development in early pregnancy. We examined metabolomic profiles using ultra performance liquid chromatography-mass spectrometry (UPLC-MS) in three independent studies: (a) venous cord plasma from normal and SGA babies, (b) plasma from a rat model of placental insufficiency and controls, and (c) early pregnancy peripheral plasma samples from women who subsequently delivered a SGA baby and controls. Multivariate analysis by cross-validated Partial Least Squares Discriminant Analysis (PLS-DA) of all 3 studies showed a comprehensive and similar disruption of plasma metabolism. A multivariate predictive model combining 19 metabolites produced by a Genetic Algorithm-based search program gave an Odds Ratio for developing SGA of 44, with an area under the Receiver Operator Characteristic curve of 0.9. Sphingolipids, phospholipids, carnitines, and fatty acids were among this panel of metabolites. The finding of a consistent discriminatory metabolite signature in early pregnancy plasma preceding the onset of SGA offers insight into disease pathogenesis and offers the promise of a robust presymptomatic screening test.

Fetal growth restriction: pathogenic mechanisms

Complex genetic and environmental mechanisms of maternal, fetal and placental origin regulate fetal growth and may contribute to fetal growth restriction (FGR). The somatotrophic regulatory factors include IGF-I, IGF-II, the IGF binding proteins (IGFBP) 1-6, IGF receptors 1 and 2, and the IGFBP specific proteases. Abnormal remodeling of utero-placental arteries and abnormal fetal-placental angiogenesis has also been implicated in FGR. The underlying molecular mediators include vascular endothelial growth factor (VEGF), placental growth factor (PlGF), VEGF receptors, VEGF binding proteins, and numerous other agents working through multiple pathways many of which still remain unknown. Expression of these major angiogenic factors appears to be regulated by local oxygen partial pressure. Future investigations may resolve many of these issues not only adding to the clarity of our understanding of the mechanisms of growth restriction but also improving clinical management.

Genetic Deletion of Placenta Growth Factor in Mice Alters Uterine NK Cells

Placenta growth factor (PlGF; formerly PGF), a vascular endothelial growth factor gene family member, is expressed in human implantation sites by maternal uterine NK (uNK) and fetal trophoblast cells. Lower than normal concentrations of blood and urinary PlGF have been associated with impending onset of pre-eclampsia, a hypertensive disease of late human gestation characterized by limited intravascular trophoblast invasion. In pregnant rodents, delivery of the PlGF antagonist sFlt-1 or S-endoglin induces pre-eclampsia-like lesions. Mice genetically deleted in PlGF reproduce, but neither their implantation sites nor their uNK cell development are described. We combined real-time PCR of endometrium from nonpregnant and gestation day (gd)6-18 C57BL6/J (B6) mice with immunohistology to analyze PlGF expression in normal mouse pregnancy. To estimate the significance of uNK cell-derived PlGF, PlGF message was quantified in mesometrial decidua from pregnant alymphoid Rag2 null/common gamma chain null mice and in laser capture-microdissected B6 uNK cells. Histopathologic consequences from PlGF deletion were also characterized in the implantation sites from PlGF null mice. In B6, decidual PlGF expression rose between gd8-16. uNK cells were among several types of cells transcribing PlGF in decidualized endometrium. Immature uNK cells, defined by their low numbers of cytoplasmic granules, were the uNK cells displaying the greatest number of transcripts. PlGF deletion promoted the early differentiation high numbers of binucleate uNK cells (gd8) but had no other significant, morphometrically detectable impact on implantation sites. Thus, in mice, PlGF plays an important role in successful uNK cell proliferation and/or differentiation.