The use of angiogenic biomarkers in maternal blood to identify which SGA fetuses will require a preterm delivery and mothers who will develop pre-eclampsia

Does the use of angiogenic biomarkers for the management of preeclampsia and fetal growth restriction improve outcomes?: Challenging the current status quo

Monitoring and timing of delivery in preterm preeclampsia and fetal growth restriction is one of the biggest challenges in Obstetrics. Finding the optimal time of delivery of these fetuses usually involves a trade-off between the severity of the disease and prematurity. So far, most clinical guidelines recommend the use of a combination between clinical, laboratory and ultrasound markers to guide the time of delivery. Angiogenic biomarkers, especially placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1), have gained significant attention in recent years for their potential role in the prediction and diagnosis of placenta-related disorders including preeclampsia and fetal growth restriction. Another potential clinical application of the angiogenic biomarkers is for the differential diagnosis of patients with chronic kidney disease, as this condition shares similar clinical features with preeclampsia. Consequently, angiogenic biomarkers have been advocated as tools for monitoring and deciding the optimal time of the delivery of fetuses affected by placental dysfunction. In this clinical opinion, we critically review the available literature on PlGF and sFlt-1 for the surveillance and time of the delivery in fetuses affected by preterm preeclampsia and fetal growth restriction. Moreover, we explore the use of angiogenic biomarkers for the differentiation between chronic kidney disease and superimposed preeclampsia.

Maternal Blood Angiogenic Factors and the Prediction of Critical Adverse Perinatal Outcomes Among Small-for-Gestational-Age Pregnancies

OBJECTIVE

Our objective was to determine whether maternal blood angiogenic factors in suspected-small-for-gestational-age (sSGA) fetuses can predict critical adverse perinatal outcomes (CAPO) and improve risk assessment.

METHODS

Women with singleton pregnancies diagnosed with sSGA, between 24 and 356/7 weeks' gestation, were included. Clinical and sonographic comprehensive evaluations were performed at enrolment. Plasma angiogenic factors, soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF), were obtained at diagnosis. In parallel, three attending maternal-fetal-medicine specialists predicted the risk (1-5 scale) of these pregnancies to develop CAPO, based on the clinical presentation. CAPOs were defined as prolonged neonatal intensive care unit hospitalization, fetal or neonatal death, and major neonatal morbidity. Statistical analysis included sensitivity, specificity, positive and negative predictive values, and receiver-operating characteristic (ROC) curve analyses.

RESULTS

Of the 79 cases included, 32 were complicated by CAPO (40.5%). In SGA fetuses with CAPO, the sFlt-1/PlGF ratio was higher (p < 0.001) and PlGF was lower (p < 0.001) as compared with uncomplicated pregnancies. The areas under the ROC curves for specialists were 0.913, 0.824, and 0.811 and for PlGF and sFlt-1/PlGF ratio 0.926 and 0.900, respectively. CAPO was more common in pregnancies with absent end-diastolic flow or reversed end-diastolic flow (AEDF or REDF) in the umbilical artery upon enrolment (91.6%). Yet, 65.6% of cases involving CAPO occurred in patients without AEDF or REDF, and 66.6% of these cases were not identified by one or more of the experts. The sFlt-1/PlGF ratio identified 92.9% of the experts' errors in this group and 100% of the errors in cases with AEDF or REDF.

CONCLUSION

Among sSGA pregnancies prior to 36 weeks' gestation, angiogenic factors testing can identify most cases later complicated with CAPO. Our data demonstrate for the first time that these markers can reduce clinician judgment errors. Incorporation of these measures into decision-making algorithms could potentially improve management, outcomes, and even health care costs.

KEY POINTS

· Angiogenic factors at diagnosis of sSGA can be used to predict CAPO.. · The sFlt-1/PlGF ratio can flag sSGA pregnancies at increased risk.. · The sFlt-1/PlGF ratio at admission of sSGA adds to clinical assessment..

The role of the PLGF in the management of pregnancies complicated with fetal microsomia

PURPOSE

To explore the contribution of maternal and fetal parameters in predicting the time interval between diagnosis and development of adverse events leading to delivery in singleton pregnancies complicated with fetal microsomia.

METHODS

Prospective study on singleton pregnancies referred to a tertiary center because of suspicion of fetal smallness in the third trimester. The study cohort included cases with fetal abdominal circumference (AC) ≤ 10th centile or estimated fetal weight ≤ 10th centile or umbilical artery pulsatitlity index ≥ 90th centile. Development of pre-eclampsia, fetal demise, and fetal deterioration diagnosed by fetal Doppler studies or fetal heart rate monitoring and leading to delivery were considered as adverse events. Maternal demographics, obstetric history, blood pressure, serum PLGF, and fetal Doppler studies were explored as predictors of the time interval between the first visit to the clinic and the diagnosis of complications.

RESULTS

In 59 women, the median incubation period from presentation to the clinic to an adverse event was 6, 2 weeks, whereas half of the pregnancies (52.5%) did not develop any adverse event. PLGF was the strongest predictor of adverse events. Both PLGF in raw values and PLGF MOM had equally good predictive ability (AUC 0.82 and 0.78 respectively). Optimal cut-off points were 177.7 pg/ml for PLGF raw values (sensitivity 83% and specificity 66.7%) and 0.277 MoM (sensitivity 76% and specificity 86.7%). On multiple Cox regression analysis, maternal systolic blood pressure, PLGF, fetal increased umbilical artery PI, and reduced CP ratio were independently associated with adverse events. Half of the pregnancies with low PLGF and only one in ten with high PLGF were delivered within two weeks after the initial visit.

CONCLUSION

Half of the pregnancies carrying a small fetus in the third trimester will not develop maternal or fetal complications. PLGF is a strong predictor of adverse events that can be used to customize antenatal care.

Soluble suppression of tumorigenicity-2 in pregnancy with a small-for-gestational-age fetus and with preeclampsia

OBJECTIVE

Preeclampsia and fetal growth disorders are pregnancy-specific conditions that share common pathophysiological mechanisms. Yet, why some patients develop preeclampsia while others experience fetal growth restriction, or a combination of both clinical presentations, is unknown. We propose that the difference in severity of the maternal inflammatory response can contribute to the clinical phenotypes of preeclampsia vs. small for gestational age (SGA). To assess this hypothesis, we measured maternal plasma concentrations of the soluble isoform of suppression of tumorigenicity-2 (sST2), a member of the interleukin-1 receptor family that buffers proinflammatory responses. Previous reports showed that serum sST2 concentrations rise in the presence of intravascular inflammation and Th1-type immune responses and are significantly higher in patients with preeclampsia compared to those with normal pregnancy. The behavior of sST2 in pregnancies complicated by SGA has not been reported. This study was conducted to compare sST2 plasma concentrations in normal pregnancies, in those with preeclampsia, and in those with an SGA fetus.

METHODS

This retrospective cross-sectional study included women with an SGA fetus (n = 52), women with preeclampsia (n = 106), and those with normal pregnancy (n = 131). Maternal plasma concentrations of sST2 were determined by enzyme-linked immunosorbent assay. Doppler velocimetry of the uterine and umbilical arteries was available in a subset of patients with SGA (42 patients and 43 patients, respectively).

RESULTS

(1) Women with an SGA fetus had a significantly higher median plasma concentration of sST2 than normal pregnant women (p = .008); (2) women with preeclampsia had a significantly higher median plasma concentration of sST2 than those with normal pregnancy (p < .001) and those with an SGA fetus (p < .001); (3) patients with SGA and abnormal uterine artery Doppler velocimetry had a higher median plasma concentration of sST2 than controls (p < .01) and those with SGA and normal uterine artery Doppler velocimetry (p = .02); (4) there was no significant difference in the median plasma sST2 concentration between patients with SGA who had normal uterine artery Doppler velocimetry and controls (p = .4); (5) among patients with SGA, those with abnormal and those with normal umbilical artery Doppler velocimetry had higher median plasma sST2 concentrations than controls (p = .001 and p = .02, respectively); and (6) there was no significant difference in the median plasma sST2 concentrations between patients with SGA who did and those who did not have abnormal umbilical artery Doppler velocimetry (p = .06).

CONCLUSIONS

Preeclampsia and disorders of fetal growth are conditions characterized by intravascular inflammation, as reflected by maternal plasma concentrations of sST2. The severity of intravascular inflammation is highest in patients with preeclampsia.

Proteomic profile of extracellular vesicles in maternal plasma of women with fetal death

OBJECTIVES

Fetal death is a complication of pregnancy caused by multiple etiologies rather than being the end-result of a single disease process. Many soluble analytes in the maternal circulation, such as hormones and cytokines, have been implicated in its pathophysiology. However, changes in the protein content of extracellular vesicles (EVs), which could provide additional insight into the disease pathways of this obstetrical syndrome, have not been examined. This study aimed to characterize the proteomic profile of EVs in the plasma of pregnant women who experienced fetal death and to evaluate whether such a profile reflected the pathophysiological mechanisms of this obstetrical complication. Moreover, the proteomic results were compared to and integrated with those obtained from the soluble fraction of maternal plasma.

METHODS

This retrospective case-control study included 47 women who experienced fetal death and 94 matched, healthy, pregnant controls. Proteomic analysis of 82 proteins in the EVs and the soluble fractions of maternal plasma samples was conducted by using a bead-based, multiplexed immunoassay platform. Quantile regression analysis and random forest models were implemented to assess differences in the concentration of proteins in the EV and soluble fractions and to evaluate their combined discriminatory power between clinical groups. Hierarchical cluster analysis was applied to identify subgroups of fetal death cases with similar proteomic profiles. A p-value of <.05 was used to infer significance, unless multiple testing was involved, with the false discovery rate controlled at the 10% level (q < 0.1). All statistical analyses were performed by using the R statistical language and environment-and specialized packages.

RESULTS

Nineteen proteins (placental growth factor, macrophage migration inhibitory factor, endoglin, regulated upon activation normal T cell expressed and presumably secreted (RANTES), interleukin (IL)-6, macrophage inflammatory protein 1-alpha, urokinase plasminogen activator surface receptor, tissue factor pathway inhibitor, IL-8, E-Selectin, vascular endothelial growth factor receptor 2, pentraxin 3, IL-16, galectin-1, monocyte chemotactic protein 1, disintegrin and metalloproteinase domain-containing protein 12, insulin-like growth factor-binding protein 1, matrix metalloproteinase-1(MMP1), and CD163) were found to have different plasma concentrations (of an EV or a soluble fraction) in women with fetal death compared to controls. There was a similar pattern of change for the dysregulated proteins in the EV and soluble fractions and a positive correlation between the log2-fold changes of proteins significant in either the EV or the soluble fraction (ρ = 0.89, p < .001). The combination of EV and soluble fraction proteins resulted in a good discriminatory model (area under the ROC curve, 82%; sensitivity, 57.5% at a 10% false-positive rate). Unsupervised clustering based on the proteins differentially expressed in either the EV or the soluble fraction of patients with fetal death relative to controls revealed three major clusters of patients.

CONCLUSION

Pregnant women with fetal death have different concentrations of 19 proteins in the EV and soluble fractions compared to controls, and the direction of changes in concentration was similar between fractions. The combination of EV and soluble protein concentrations revealed three different clusters of fetal death cases with distinct clinical and placental histopathological characteristics.

Usefulness of angiogenic factors in prenatal counseling of late-onset fetal growth-restricted and small-for-gestational-age gestations: a prospective observational study

OBJECTIVES

To create a predictive model including biomarkers and evaluate its ability to predict adverse perinatal outcomes in late-onset small fetuses, ultimately helping to provide individualized counseling at the time of diagnosis.

METHODS

This was a prospective observational study, including singleton pregnancies with an estimated fetal weight (EFW) below the 10th percentile, at a gestational age between 32 + 0 and 36 + 6 weeks of gestation (WG). Variables recorded at diagnosis to predict adverse pregnancy outcomes were: soluble fms-like tyrosine-kinase-1 to placental growth factor ratio (sFlt-1/PlGF), fetal Doppler (umbilical artery and middle cerebral artery), uterine artery pulsatility index (UtAPI), EFW percentile, gestational age, and the presence of maternal risk factors for placental insufficiency. Logistic regression models were developed for the prediction of three co-primary outcomes: composite adverse perinatal outcomes (APO), and the need for elective delivery before 35 or 37 WG.

RESULTS

Sixty (52.2%) fetal growth restricted (FGR) and 55 (47.8%) small for gestational age (SGA) were enrolled. Thirteen (11.3%) women needed elective delivery before 35 WG and 27 (23.5%) women before 37 WG. At least one APO occurred in 43 (37.4%) pregnancies. The best marker in univariate analyses was the sFlt-1/PlGF ratio [AUC = 0.932 (95% CI, 0.864-0.999)]. The multivariate model including sFlt-1/PlGF showed a better predictive performance for APO than the multivariate model without sFlt-1/PlGF (P < 0.024).

CONCLUSIONS

sFlt-1/PlGF is a good predictor of APO at the time of late-onset FGR/SGA diagnosis. Our predictive models may be useful to provide early individualized prenatal counseling in this group of women. Further studies are needed to validate these preliminary findings in a larger cohort.

Accuracy of placental growth factor alone or in combination with soluble fms-like tyrosine kinase-1 or maternal factors in detecting preeclampsia in asymptomatic women in the second and third trimesters: a systematic review and meta-analysis

OBJECTIVE

This study aimed to: (1) identify all relevant studies reporting on the diagnostic accuracy of maternal circulating placental growth factor) alone or as a ratio with soluble fms-like tyrosine kinase-1), and of placental growth factor-based models (placental growth factor combined with maternal factors±other biomarkers) in the second or third trimester to predict subsequent development of preeclampsia in asymptomatic women; (2) estimate a hierarchical summary receiver-operating characteristic curve for studies reporting on the same test but different thresholds, gestational ages, and populations; and (3) select the best method to screen for preeclampsia in asymptomatic women during the second and third trimester of pregnancy by comparing the diagnostic accuracy of each method.

DATA SOURCES

A systematic search was performed through MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform databases from January 1, 1985 to April 15, 2021.

STUDY ELIGIBILITY CRITERIA

Studies including asymptomatic singleton pregnant women at >18 weeks' gestation with risk of developing preeclampsia were evaluated. We included only cohort or cross-sectional test accuracy studies reporting on preeclampsia outcome, allowing tabulation of 2×2 tables, with follow-up available for >85%, and evaluating performance of placental growth factor alone, soluble fms-like tyrosine kinase-1- placental growth factor ratio, or placental growth factor-based models. The study protocol was registered on the International Prospective Register Of Systematic Reviews (CRD 42020162460).

METHODS

Because of considerable intra- and interstudy heterogeneity, we computed the hierarchical summary receiver-operating characteristic plots and derived diagnostic odds ratios, β, θi, and Λ for each method to compare performances. The quality of the included studies was evaluated by the QUADAS-2 tool.

RESULTS

The search identified 2028 citations, from which we selected 474 studies for detailed assessment of the full texts. Finally, 100 published studies met the eligibility criteria for qualitative and 32 for quantitative syntheses. Twenty-three studies reported on performance of placental growth factor testing for the prediction of preeclampsia in the second trimester, including 16 (with 27 entries) that reported on placental growth factor test alone, 9 (with 19 entries) that reported on the soluble fms-like tyrosine kinase-1-placental growth factor ratio, and 6 (16 entries) that reported on placental growth factor-based models. Fourteen studies reported on performance of placental growth factor testing for the prediction of preeclampsia in the third trimester, including 10 (with 18 entries) that reported on placental growth factor test alone, 8 (with 12 entries) that reported on soluble fms-like tyrosine kinase-1-placental growth factor ratio, and 7 (with 12 entries) that reported on placental growth factor-based models. For the second trimester, Placental growth factor-based models achieved the highest diagnostic odds ratio for the prediction of early preeclampsia in the total population compared with placental growth factor alone and soluble fms-like tyrosine kinase-1-placental growth factor ratio (placental growth factor-based models, 63.20; 95% confidence interval, 37.62-106.16 vs soluble fms-like tyrosine kinase-1-placental growth factor ratio, 6.96; 95% confidence interval, 1.76-27.61 vs placental growth factor alone, 5.62; 95% confidence interval, 3.04-10.38); placental growth factor-based models had higher diagnostic odds ratio than placental growth factor alone for the identification of any-onset preeclampsia in the unselected population (28.45; 95% confidence interval, 13.52-59.85 vs 7.09; 95% confidence interval, 3.74-13.41). For the third trimester, Placental growth factor-based models achieved prediction for any-onset preeclampsia that was significantly better than that of placental growth factor alone but similar to that of soluble fms-like tyrosine kinase-1-placental growth factor ratio (placental growth factor-based models, 27.12; 95% confidence interval, 21.67-33.94 vs placental growth factor alone, 10.31; 95% confidence interval, 7.41-14.35 vs soluble fms-like tyrosine kinase-1-placental growth factor ratio, 14.94; 95% confidence interval, 9.42-23.70).

CONCLUSION

Placental growth factor with maternal factors ± other biomarkers determined in the second trimester achieved the best predictive performance for early preeclampsia in the total population. However, in the third trimester, placental growth factor-based models had predictive performance for any-onset preeclampsia that was better than that of placental growth factor alone but similar to that of soluble fms-like tyrosine kinase-1-placental growth factor ratio. Through this meta-analysis, we have identified a large number of very heterogeneous studies. Therefore, there is an urgent need to develop standardized research using the same models that combine serum placental growth factor with maternal factors ± other biomarkers to accurately predict preeclampsia. Identification of patients at risk might be beneficial for intensive monitoring and timing delivery.

Risk Scoring Systems for Preterm Birth and Their Performance: A Systematic Review

Introduction: Nowadays, the risk stratification of preterm birth (PTB) and its prediction remain a challenge. Many risk factors associated with PTB have been identified, and risk scoring systems (RSSs) have been developed to face this challenge. The objectives of this systematic review were to identify RSSs for PTB, the variables they consist of, and their performance. Materials and methods: Two databases were searched, and two authors independently performed the screening and eligibility phases. Records studying an RSS, based on specified variables, with an evaluation of the predictive value for PTB, were considered eligible. Reference lists of eligible studies and review articles were also searched. Data from the included studies were extracted. Results: A total of 56 studies were included in this review. The most frequently incorporated variables in the RSS included in this review were maternal age, weight, history of smoking, history of previous PTB, and cervical length. The performance measures varied widely among the studies, with sensitivity ranging between 4.2% and 92.0% and area under the curve (AUC) between 0.59 and 0.95. Conclusions: Despite the recent technological and scientifical evolution with a better understanding of variables related to PTB and the definition of new ultrasonographic parameters and biomarkers associated with PTB, the RSS's ability to predict PTB remains poor in most situations, thus compromising the integration of a single RSS in clinical practice. The development of new RSSs, the identification of new variables associated with PTB, and the elaboration of a large reference dataset might be a step forward to tackle the problem of PTB.

Maternal Serum Angiogenic Profile and Its Correlations with Ultrasound Parameters and Perinatal Results in Normotensive and Preeclamptic Pregnancies Complicated by Fetal Growth Restriction

FGR is a complication of pregnancy in which the fetus does not reach its programmed growth potential due to placental reasons and it is the single largest risk factor of stillbirth. Babies with FGR are at increased risk of mortality and morbidity not only in the perinatal period, but also in later life. FGR presents a huge challenge for obstetricians in terms of its detection and further monitoring of pregnancy. The ultrasound is the gold standard here; apart from assessing fetal weight, it is used to measure Doppler flows in maternal and fetal circulation. It seems that additional tests, like biochemical angiogenic factors measurement would be helpful in diagnosing FGR, identifying fetuses at risk and adjusting the surveillance model. The study aimed to assess the potential relationship between the concentration of sEng, sFlt-1, PlGF, and the sFlt-1/PlGF ratio in maternal serum at delivery and maternal and fetal Doppler flow measurements as well as perinatal outcomes in pregnancies complicated by FGR with and without PE, isolated PE cases and normal pregnancies. The use of angiogenic markers is promising not only in PE but also in FGR. Numerous correlations between ultrasound and Doppler studies, perinatal outcomes and disordered angiogenesis marker levels in maternal serum suggest that biochemical parameters have a great potential to be used as a complementary method to diagnose and monitor pregnancies with FGR. The, PlGF in particular, could play an outstanding role in this regard.

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

BACKGROUND

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Similar Pro- and Antiangiogenic Profiles Close to Delivery in Different Clinical Presentations of Two Pregnancy Syndromes: Preeclampsia and Fetal Growth Restriction

The purpose of this study was to evaluate serum levels of anti- and pro-angiogenic substances measured using enzyme-linked immunosorbent assays and their ratios in pregnancies complicated by different clinical subsets of placental ischemic syndrome: preeclampsia and/or fetal growth restriction. A prospective case-control study was performed consisting of 77 singleton pregnancies complicated by preeclampsia, preeclampsia with concurrent fetal growth restriction (FGR), and isolated normotensive FGR pairwise matched by gestational age with healthy pregnancies. The entire study cohort was analyzed with respect to adverse pregnancy outcomes that occurred. In all investigated subgroups, placental growth factor (PlGF) was lower and soluble endoglin (sEng), the soluble fms-like tyrosine kinase-1-sFlt-1/PlGF and sFlt-1*sEng/PlGF ratios were higher than in the control group. The differences were most strongly pronounced in the PE with concurrent FGR group and in the sFlt-1/PlGF ratio. The highest sFlt-1 values in preeclamptic patients suggest that this substance may be responsible for reaching the threshold needed for PE to develop as a maternal manifestation of ischemic placental disease. The FGR is characterized by an elevated maternal sFlt-1/PlGF ratio, which boosts at the moment of indicated delivery due to fetal risk. We concluded that angiogenic imbalance is reflective of placental disease regardless of its clinical manifestation in the mother, and may be used as support for the diagnosis and prognosis of FGR.

The Association of IL-17 and PlGF/sENG Ratio in Pre-Eclampsia and Adverse Pregnancy Outcomes

The aim of the study was to assess the role of concentrations of interleukin-17 (IL-17), placental growth factor (PlGF) and soluble endoglin (sENG), as well as the PlGF/sENG ratio in pregnancy complicated by pre-eclampsia (PE) and normal pregnancy. The concentrations of IL-17, PlGF and sENG were measured with the use of immunoenzymatic methods. The concentrations of IL-17 were significantly higher in PE patients when compared to control patients. In the group of patients with PE, the levels of IL-17 positively correlated with systolic blood pressure. On the other hand, IL-17 negatively correlated with neonatal birth weight. The concentrations of PLGF were significantly lower and sENG significantly higher in studied patients when compared to controls. The PlGF/sENG ratio in the PE group was significantly lower when compared to healthy third trimester pregnant patients. In the study group, negative correlations were observed between the sENG concentrations and thrombocyte levels. The higher concentrations of IL-17 in PE could suggest its role as an inflammatory agent in the pathogenesis of the syndrome. Moreover, the negative correlation between IL-17 and a neonatal birth weight could suggest the role of the cytokine in the development of fetal growth restriction (FGR) associated with PE. It seems possible that IL-17 can be a useful marker of the risk of FGR in pregnancy complicated by PE. Furthermore, the results suggested the potential role of sENG and the PlGF/sENG ratio in the prediction of adverse outcomes such as HELLP syndrome and DIC.

Human Plasma Proteome During Normal Pregnancy

The human plasma proteome is underexplored despite its potential value for monitoring health and disease. Herein, using a recently developed aptamer-based platform, we profiled 7288 proteins in 528 plasma samples from 91 normal pregnancies (Gene Expression Omnibus identifier GSE206454). The coefficient of variation was <20% for 93% of analytes (median 7%), and a cross-platform correlation for selected key angiogenic and anti-angiogenic proteins was significant. Gestational age was associated with changes in 953 proteins, including highly modulated placenta- and decidua-specific proteins, and they were enriched in biological processes including regulation of growth, angiogenesis, immunity, and inflammation. The abundance of proteins corresponding to RNAs specific to populations of cells previously described by single-cell RNA-Seq analysis of the placenta was highly modulated throughout gestation. Furthermore, machine learning-based prediction of gestational age and of time from sampling to term delivery compared favorably with transcriptomic models (mean absolute error of 2 weeks). These results suggested that the plasma proteome may provide a non-invasive readout of placental cellular dynamics and serve as a blueprint for investigating obstetrical disease.

Toward a new taxonomy of obstetrical disease: improved performance of maternal blood biomarkers for the great obstetrical syndromes when classified according to placental pathology

BACKGROUND

The major challenge for obstetrics is the prediction and prevention of the great obstetrical syndromes. We propose that defining obstetrical diseases by the combination of clinical presentation and disease mechanisms as inferred by placental pathology will aid in the discovery of biomarkers and add specificity to those already known.

OBJECTIVE

To describe the longitudinal profile of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PlGF/sFlt-1 ratio throughout gestation, and to determine whether the association between abnormal biomarker profiles and obstetrical syndromes is strengthened by information derived from placental examination, eg, the presence or absence of placental lesions of maternal vascular malperfusion.

STUDY DESIGN

This retrospective case cohort study was based on a parent cohort of 4006 pregnant women enrolled prospectively. The case cohort of 1499 pregnant women included 1000 randomly selected patients from the parent cohort and all additional patients with obstetrical syndromes from the parent cohort. Pregnant women were classified into six groups: 1) term delivery without pregnancy complications (n=540; control); 2) preterm labor and delivery (n=203); 3) preterm premature rupture of the membranes (n=112); 4) preeclampsia (n=230); 5) small-for-gestational-age neonate (n=334); and 6) other pregnancy complications (n=182). Maternal plasma concentrations of PlGF and sFlt-1 were determined by enzyme-linked immunosorbent assays in 7560 longitudinal samples. Placental pathologists, masked to clinical outcomes, diagnosed the presence or absence of placental lesions of maternal vascular malperfusion. Comparisons between mean biomarker concentrations in cases and controls were performed by utilizing longitudinal generalized additive models. Comparisons were made between controls and each obstetrical syndrome with and without subclassifying cases according to the presence or absence of placental lesions of maternal vascular malperfusion.

RESULTS

1) When obstetrical syndromes are classified based on the presence or absence of placental lesions of maternal vascular malperfusion, significant differences in the mean plasma concentrations of PlGF, sFlt-1, and the PlGF/sFlt-1 ratio between cases and controls emerge earlier in gestation; 2) the strength of association between an abnormal PlGF/sFlt-1 ratio and the occurrence of obstetrical syndromes increases when placental lesions of maternal vascular malperfusion are present (adjusted odds ratio [aOR], 13.6 vs 6.7 for preeclampsia; aOR, 8.1 vs 4.4 for small-for-gestational-age neonates; aOR, 5.5 vs 2.1 for preterm premature rupture of the membranes; and aOR, 3.3 vs 2.1 for preterm labor (all P<0.05); and 3) the PlGF/sFlt-1 ratio at 28 to 32 weeks of gestation is abnormal in patients who subsequently delivered due to preterm labor with intact membranes and in those with preterm premature rupture of the membranes if both groups have placental lesions of maternal vascular malperfusion. Such association is not significant in patients with these obstetrical syndromes who do not have placental lesions.

CONCLUSION

Classification of obstetrical syndromes according to the presence or absence of placental lesions of maternal vascular malperfusion allows biomarkers to be informative earlier in gestation and enhances the strength of association between biomarkers and clinical outcomes. We propose that a new taxonomy of obstetrical disorders informed by placental pathology will facilitate the discovery and implementation of biomarkers as well as the prediction and prevention of such disorders.

Study protocol for a randomized trial on timely delivery versus expectant management in late preterm small for gestational age pregnancies with an abnormal umbilicocerebral ratio (UCR): the DRIGITAT study

BACKGROUND

The clinical inability to correctly identify late fetal growth restriction (FGR) within a group of fetuses who are identified as small for gestational age (SGA) is an everyday problem for all obstetrician-gynecologists. This leads to substantial overtreatment of healthy small fetuses but also inadequate detection of the growth-restricted fetuses that may benefit from timely delivery. Redistribution of the fetal circulation, signaled by an abnormal ratio of the Doppler velocity flow profiles of the umbilical artery and the middle cerebral artery, more specifically an increased umbilicocerebral ratio (UCR) (or its inverse: a decreased cerebroplacental ratio (CPR)), is an adaptation to chronic hypoxemia and nutritional scarcity with long-term consequences in survivors. The relevance of an abnormal UCR has been signaled extensively, and there is a general consensus that it is a signal of FGR, independent of size, with a strong association with poor outcomes. Yet, in the current literature, no comparisons of a monitoring-delivery strategy based on unfavorable UCR have been published. The objective of the Doppler Ratio In fetal Growth restriction Intervention Trial At (near) Term (DRIGITAT) is to evaluate if the timing of the delivery based on an abnormal UCR in late preterm fetuses identified as SGA improves neurodevelopmental outcomes at 2 years of age.

METHODS

The DRIGITAT study is a national multicenter cohort study of women with singleton pregnancies between 32 and 37 weeks of gestation identified as SGA, with a nested randomized controlled trial (RCT) in case of an abnormal UCR (> 0.8). Recruiting centers are in The Netherlands. In the nested RCT, women are randomized to either immediate induction of labor or expectant management from 34 weeks in case of severely abnormal size (EFW or FAC < p3) and from 36 weeks in case of mildly abnormal size (EFW or FAC p3-p10). The primary outcome measure is the 7-point average difference in the composite cognitive score (CCS) and composite motor score (CMS) on the Bayley-3 at 2 years. Secondary outcome measures include a composite outcome of neonatal morbidity, perinatal mortality, mode of delivery, maternal quality of life, costs, and predictive value of serum biomarkers. Analyses will be by intention to treat. The required sample size is determined for the nested RCT as 185 patients.

DISCUSSION

This study will provide insight into the diagnostic efficacy of UCR measurement in the evaluation of SGA fetuses in order to differentiate the healthy SGA fetus from the growth-restricted fetus and to determine if a fetus with abnormal UCR benefits from early delivery.

TRIAL REGISTRATION

Healthcare Evaluation Netherlands NTR6663 . Registered on 14 August 2017.

Angiogenic Imbalance and Inflammatory Biomarkers in the Prediction of Hypertension as Well as Obstetric and Perinatal Complications in Women with Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) increases the risk of hypertensive disorders of pregnancy (HDP). We aimed to analyze the altered inflammatory markers and angiogenic factors among women with GDM to identify pregnant women at higher risk of developing HDP. Methods: This was a prospective study of 149 women without hypertension diagnosed in the third trimester with GDM. Inflammatory markers and angiogenic factors were measured at 28−32 weeks of pregnancy. Obstetric and perinatal outcomes were evaluated. Results: More than eight percent of the women developed HDP. Higher levels of the soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PIGF) ratio (4.9 ± 2.6 versus 2.3 ± 1.3, respectively; p < 0.001) and leptin (10.9 ± 0.8 versus 10.08 ± 1.1, respectively; p = 0.038), as well as lower levels of adiponectin (10.5 ± 1.3 versus 12.9 ± 2.7, respectively; p = 0.031), were seen in women who developed HDP versus normotensive women with GDM. A multivariable logistic regression analysis showed that adiponectin had a protective effect with 0.45-fold odds (0.23−0.83; p = 0.012), and that the sFlt-1/PIGF ratio was associated with 2.70-fold odds of developing HDP (CI 95%: 1.24−5.86; p = 0.012). Conclusion: An increase in angiogenic imbalance in the sFlt-1/PIGF ratio in women with GDM was detected and may be an indicator of developing HDP in addition to any subsequent obstetric and perinatal complications.

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

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

Eclampsia in the 21st century

The reported incidence of eclampsia is 1.6 to 10 per 10,000 deliveries in developed countries, whereas it is 50 to 151 per 10,000 deliveries in developing countries. In addition, low-resource countries have substantially higher rates of maternal and perinatal mortalities and morbidities. This disparity in incidence and pregnancy outcomes may be related to universal access to prenatal care, early detection of preeclampsia, timely delivery, and availability of healthcare resources in developed countries compared to developing countries. Because of its infrequency in developed countries, many obstetrical providers and maternity units have minimal to no experience in the acute management of eclampsia and its complications. Therefore, clear protocols for prevention of eclampsia in those with severe preeclampsia and acute treatment of eclamptic seizures at all levels of healthcare are required for better maternal and neonatal outcomes. Eclamptic seizure will occur in 2% of women with preeclampsia with severe features who are not receiving magnesium sulfate and in <0.6% in those receiving magnesium sulfate. The pathogenesis of an eclamptic seizure is not well understood; however, the blood-brain barrier disruption with the passage of fluid, ions, and plasma protein into the brain parenchyma remains the leading theory. New data suggest that blood-brain barrier permeability may increase by circulating factors found in preeclamptic women plasma, such as vascular endothelial growth factor and placental growth factor. The management of an eclamptic seizure will include supportive care to prevent serious maternal injury, magnesium sulfate for prevention of recurrent seizures, and promoting delivery. Although routine imagining following an eclamptic seizure is not recommended, the classic finding is referred to as the posterior reversible encephalopathy syndrome. Most patients with posterior reversible encephalopathy syndrome will show complete resolution of the imaging finding within 1 to 2 weeks, but routine imaging follow-up is unnecessary unless there are findings of intracranial hemorrhage, infraction, or ongoing neurologic deficit. Eclampsia is associated with increased risk of maternal mortality and morbidity, such as placental abruption, disseminated intravascular coagulation, pulmonary edema, aspiration pneumonia, cardiopulmonary arrest, and acute renal failure. Furthermore, a history of eclamptic seizures may be related to long-term cardiovascular risk and cognitive difficulties related to memory and concentration years after the index pregnancy. Finally, limited data suggest that placental growth factor levels in women with preeclampsia are superior to clinical markers in prediction of adverse pregnancy outcomes. This data may be extrapolated to the prediction of eclampsia in future studies. This summary of available evidence provides data and expert opinion on possible pathogenesis of eclampsia, imaging findings, differential diagnosis, and stepwise approach regarding the management of eclampsia before delivery and after delivery as well as current recommendations for the prevention of eclamptic seizures in women with preeclampsia.

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

BACKGROUND

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Maternal and fetal vascular lesions of malperfusion in the placentas associated with fetal and neonatal death: results of a prospective observational study

BACKGROUND

Fetal death is one of the major adverse pregnancy outcomes and is common in low- and middle-income countries. Placental lesions may play an important role in the etiology of fetal and neonatal deaths. Previous research relating placental lesions to fetal death causation was hindered by a lack of agreement on a placental classification scheme. The Amsterdam consensus statement that was published in 2016 focused its attention on malperfusions in the maternal and fetal placental circulations.

OBJECTIVE

This study aimed to investigate the relationships of placental maternal and fetal vascular malperfusions in fetal and neonatal deaths, focusing on the most important maternal clinical conditions in the pathway to fetal and neonatal deaths, such as maternal hypertension, antepartum hemorrhage, and decreased fetal growth.

STUDY DESIGN

This was a prospective, observational cohort study conducted at 2 Asian sites. The data collected included clinical history, gross and histologic evaluations of the placenta, and several other investigations and were used to determine the cause of death. The placenta was evaluated at both sites using the Amsterdam consensus framework. We estimated the risk of placental maternal and fetal vascular malperfusions in fetal and neonatal deaths.

RESULTS

Between July 2018 and January 2020 in India and Pakistan, 1633 women with placentas available for the study provided consent. Of these women, 814 had fetal deaths, 618 had preterm live births and subsequent neonatal deaths, and 201 had term live births. The prevalence of maternal vascular malperfusion was higher in the placentas associated with fetal deaths (58.4%) and preterm neonatal deaths (31.1%) than in the placentas associated with term live births (15.4%). Adjusting for site, maternal vascular malperfusion had a relative risk of 3.88 (95% confidence interval, 2.70-5.59) in fetal deaths vs term live births and a relative risk of 2.07 (95% confidence interval, 1.41-3.02) in preterm neonatal deaths vs term live births. Infarcts and distal villous hypoplasia were the most common histologic components of maternal vascular malperfusion. Compared with maternal vascular malperfusion (58.4%), fetal vascular malperfusion was less common in the placentas associated with fetal deaths (19.0%). However, there were higher frequencies of fetal vascular malperfusion in the placentas associated with fetal deaths (19.0%) than in placentas associated with neonatal deaths (8.3%) or term live birth (5.0%). Adjusting for site, fetal vascular malperfusion had a relative risk of 4.09 (95% confidence interval, 2.15-7.75) in fetal deaths vs term live births and a relative risk of 1.77 (95% confidence interval, 0.90-3.49) in preterm neonatal deaths vs term live births. Furthermore, there was a higher incidence of maternal vascular malperfusion in cases of maternal hypertension (71.4%), small for gestational age (69.9%), and antepartum hemorrhage (59.1%) than in cases of fetal deaths with none of these conditions (43.3%). There was no significant difference in the occurrence of fetal vascular malperfusion in the 4 clinical categories.

CONCLUSION

Histologic examination of the placenta, especially for malperfusion disorders, is crucial in elucidating pathways to fetal and neonatal deaths in preterm infants. In particular, focusing on placental maternal and fetal vascular malperfusions during pregnancy is a means to identify fetuses at risk of fetal death and is an important strategy to reduce the risk of fetal death early delivery. We hope that the increased risk of fetal and neonatal deaths in these pregnancies can be reduced by the development of an intervention that reduces the likelihood of developing maternal and fetal vascular malperfusion.

Performance of a validated spontaneous preterm delivery predictor in South Asian and Sub-Saharan African women: a nested case control study

OBJECTIVES

To address the disproportionate burden of preterm birth (PTB) in low- and middle-income countries, this study aimed to (1) verify the performance of the United States-validated spontaneous PTB (sPTB) predictor, comprised of the IBP4/SHBG protein ratio, in subjects from Bangladesh, Pakistan and Tanzania enrolled in the Alliance for Maternal and Newborn Health Improvement (AMANHI) biorepository study, and (2) discover biomarkers that improve performance of IBP4/SHBG in the AMANHI cohort.

STUDY DESIGN

The performance of the IBP4/SHBG biomarker was first evaluated in a nested case control validation study, then utilized in a follow-on discovery study performed on the same samples. Levels of serum proteins were measured by targeted mass spectrometry. Differences between the AMANHI and U.S. cohorts were adjusted using body mass index (BMI) and gestational age (GA) at blood draw as covariates. Prediction of sPTB < 37 weeks and < 34 weeks was assessed by area under the receiver operator curve (AUC). In the discovery phase, an artificial intelligence method selected additional protein biomarkers complementary to IBP4/SHBG in the AMANHI cohort.

RESULTS

The IBP4/SHBG biomarker significantly predicted sPTB < 37 weeks (n = 88 vs. 171 terms ≥ 37 weeks) after adjusting for BMI and GA at blood draw (AUC= 0.64, 95% CI: 0.57-0.71, p < .001). Performance was similar for sPTB < 34 weeks (n = 17 vs. 184 ≥ 34 weeks): AUC = 0.66, 95% CI: 0.51-0.82, p = .012. The discovery phase of the study showed that the addition of endoglin, prolactin, and tetranectin to the above model resulted in the prediction of sPTB < 37 with an AUC= 0.72 (95% CI: 0.66-0.79, p-value < .001) and prediction of sPTB < 34 with an AUC of 0.78 (95% CI: 0.67-0.90, p < .001).

CONCLUSION

A protein biomarker pair developed in the U.S. may have broader application in diverse non-U.S. populations.

Placenta morphology and biomarkers in pregnancies with congenital heart disease - A systematic review

Impaired placentation is an important contributing factor to intra-uterine growth restriction and pre-eclampsia in fetuses with congenital heart defects (CHD). These pregnancy complications occur more frequently in pregnancies with fetal CHD. One of the most important factors influencing the life of children with CHD is neurodevelopmental delay, which seems to start already in utero. Delayed neurodevelopment in utero may be correlated or even (partly) explained by impaired placentation in CHD cases. This systematic review provides an overview of published literature on placental development in pregnancies with fetal CHD. A systematic search was performed and the Newcastle-Ottawa scale was used to access data quality. Primary outcomes were placenta size and weight, vascular and villous architecture, immunohistochemistry, angiogenic biomarkers and/or placental gene expression. A total of 1161 articles were reviewed and 21 studies were included. Studies including CHD with a genetic disorder or syndrome and/or multiple pregnancies were excluded. Lower placental weight and elevated rates of abnormal umbilical cord insertions were found in CHD. Cases with CHD more frequently showed microscopic placental abnormalities (i.e. abnormal villous maturation and increased maternal vascular malperfusion lesions), reduced levels of angiogenic biomarkers and increased levels of anti-angiogenic biomarkers in maternal serum and umbilical cord blood. Altered gene expression involved in placental development and fetal growth were found in maternal serum and CHD placentas. In conclusion, abnormal placentation is found in CHD. More extensive studies are needed to elucidate the contribution of impaired placentation to delayed neurodevelopment in CHD cases.

Preventable stillbirths in India and Pakistan: a prospective, observational study

OBJECTIVE

Stillbirths occur 10-20 times more frequently in low-income settings compared with high-income settings. We created a methodology to define the proportion of stillbirths that are potentially preventable in low-income settings and applied it to stillbirths in sites in India and Pakistan.

DESIGN

Prospective observational study.

SETTING

Three maternity hospitals in Davangere, India and a large public hospital in Karachi, Pakistan.

POPULATION

All cases of stillbirth at ≥20 weeks of gestation occurring from July 2018 to February 2020 were screened for participation; 872 stillbirths were included in this analysis.

METHODS

We prospectively defined the conditions and gestational ages that defined the stillbirth cases considered potentially preventable. Informed consent was sought from the parent(s) once the stillbirth was identified, either before or soon after delivery. All information available, including obstetric and medical history, clinical course, fetal heart sounds on admission, the presence of maceration as well as examination of the stillbirth after delivery, histology, and polymerase chain reaction for infectious pathogens of the placenta and various fetal tissues, was used to assess whether a stillbirth was potentially preventable.

MAIN OUTCOME MEASURES

Whether a stillbirth was determined to be potentially preventable and the criteria for assignment to those categories.

RESULTS

Of 984 enrolled, 872 stillbirths at ≥20 weeks of gestation met the inclusion criteria and were included; of these, 55.5% were deemed to be potentially preventable. Of the 649 stillbirths at ≥28 weeks of gestation and ≥1000 g birthweight, 73.5% were considered potentially preventable. The most common conditions associated with a potentially preventable stillbirth at ≥28 weeks of gestation and ≥1000 g birthweight were small for gestational age (SGA) (52.8%), maternal hypertension (50.2%), antepartum haemorrhage (31.4%) and death that occurred after hospital admission (15.7%).

CONCLUSIONS

Most stillbirths in these sites were deemed preventable and were often associated with maternal hypertension, antepartum haemorrhage, SGA and intrapartum demise.

TWEETABLE ABSTRACT

Most stillbirths are preventable by better care for women with hypertension, growth restriction and antepartum haemorrhage.

Recent advances in the diagnosis and management of pre-eclampsia

Pre-eclampsia is an elusive condition to diagnose and a complex disease to manage. There have been recent developments in prediction, prevention, diagnosis, and management. Risk modelling has been used to identify women at highest risk of developing pre-eclampsia as well as predicting maternal adverse outcomes in confirmed disease. New evidence has shown that aspirin prophylaxis significantly reduces early onset pre-eclampsia as well as preterm birth. The criteria for the diagnosis of pre-eclampsia are evolving, and proteinuria is no longer a pre-requisite to make a diagnosis. Angiogenic biomarker testing accelerates diagnosis as well as minimises adverse maternal outcomes and has been incorporated into national guidelines. Emerging evidence demonstrates that expedited delivery in late preterm pre-eclampsia may be protective against maternal adverse outcomes but increase the risk of neonatal unit admission. Both women and their offspring are at increased risk of long-term health complications following pre-eclampsia, and it is important that postnatal health is optimised. This article summarises recent developments in the field of pre-eclampsia research, evaluating the impact on clinical care for women at risk of, or with suspected or confirmed, pre-eclampsia.

Prenatal serum sFlt-1/PlGF ratio predicts the adverse neonatal outcomes among small-for-gestational-age fetuses in normotensive pregnant women: A prospective cohort study

We investigated the predictive value of the soluble fms-like tyrosine kinase-1 (sFlt-1)-to-placental growth factor (PlGF) ratio for poor neonatal outcomes of SGA neonates in the absence of preeclampsia.This prospective cohort study included 530 singleton pregnant women who attended a prenatal screening program at a single institution. The sFlt-1/PlGF values at 24 to 28+6 weeks and 29 to 36+6 weeks of gestation were analyzed and compared between control and SGA group (subdivided as with normal neonatal outcomes and with poor neonatal outcomes).After 22 preeclampsia cases were excluded, 47 SGA neonates and 461 control neonates were included. In the SGA group, 17 neonates had adverse neonatal outcomes (36.1%, 17/47). The mean (±D) sFlt-1/PlGF ratio of early third trimester was significantly higher in SGA with averse neonatal outcome group than in the control group (14.42 ± 23.8 vs 109.12 3.96, P = .041) and the ratio retained an independent and significant association with SGA with adverse neonatal outcomes (odds ratio = 1.017, P = .01). A sFlt-1/PlGF ratio cut-off of 28.15 at 29 to 36+6 weeks significantly predicted adverse outcomes among SGA neonates (sensitivity = 76.9%, specificity = 88%).In this study, sFlt-1/PlGF ratio at 29 to 36 + 6wks of SGA with adverse neonatal outcome group was significantly higher than control group. This study suggests the feasibility of the sFlt-1/PlGF ratio as helpful objective measurement for predicting the adverse SGA neonatal outcome by providing sFlt-1/PlGF cut-off value.

Longitudinal plasma inflammatory proteome profiling during pregnancy in the Born into Life study

The maternal immune system is going through considerable changes during pregnancy. However, little is known about the determinants of the inflammatory proteome and its relation to pregnancy stages. Our aim was to investigate the plasma inflammatory proteome before, during and after pregnancy. In addition we wanted to test whether maternal and child outcomes were associated with the proteome. A cohort of 94 healthy women, enrolled in a longitudinal study with assessments at up to five time points around pregnancy, ninety-two inflammatory proteins were analysed in plasma with a multiplex Proximity Extension Assay. First, principal components analysis were applied and thereafter regression modelling while correcting for multiple testing. We found profound shifts in the overall inflammatory proteome associated with pregnancy stage after multiple testing (p < .001). Moreover, maternal body mass index (BMI) was associated with inflammatory proteome primarily driven by VEGFA, CCL3 and CSF-1 (p < .05). The levels of most inflammatory proteins changed substantially during pregnancy and some of these were related to biological processes such as regulation of immune response. Maternal BMI was significantly associated with higher levels of three inflammation proteins calling for more research in the interplay between pregnancy, inflammation and BMI.

Analysis of perinatal risk factors for small-for-gestational-age and appropriate-for-gestational-age late-term infants

To investigate the potential risk factors for small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) late-term infants, 100 cases of single full-term SGA infants delivered in the Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University in 2017 were enrolled as the SGA group. A total of 100 healthy AGA who were born at the same time with the same gestational age were randomly included as the control group. The perinatal and postpartum adverse conditions of the two groups were recorded, and Apgar tests were performed on all newborns at 1 min (T1), 5 min (T2) and 10 min (T3) after birth. A follow-up survey was conducted in all patients at 6 and 12 months of age. At the second follow-up, the development quotient of the children was measured using the Gesell Developmental Schedule, and the perinatal risk factors of SGA were analyzed. The incidence of intrauterine distress, respiratory distress syndrome and infectious disease in the SGA group was significantly higher compared with that in the AGA group (P<0.05). The Apgar scores at T1, T2 and T3 were significantly lower in the SGA group compared with the AGA group (P<0.05). The Apgar score at T1 was lower compared with that at T2 in the SGA group (P<0.05), and the Apgar score at T2 was lower compared with that at T3 (P<0.05). The length of hospital stay in the SGA group was significantly longer compared with that in the AGA group (P<0.05). The development quotient at the 6 and 12th month in the SGA group was significantly lower compared with that in the AGA group (P<0.05). Logistic regression analysis showed that there was no correlation between SGA and maternal age, regardless of firstborn status, neonatal sex, mode of delivery and living environment. SGA was significantly associated with umbilical cord abnormalities, maternal pregnancy-induced hypertension, gestational diabetes, pregnancy infection and intrauterine distress (P<0.05). An abnormal umbilical cord, maternal pregnancy-induced hypertension, gestational diabetes, infection during pregnancy and intrauterine distress are all perinatal risk factors for SGA. Effective interventions are needed in clinical assessment to prevent the occurrence of SGA.

Utilization of a chicken embryo membrane model for evaluation of embryonic vascular toxicity of Dorema ammoniacum

OBJECTIVE

Extensive research has been done to assess the efficacy of herbs for treating different disorders. Dorema ammoniacum (D. ammoniacum) is used in folk medicines for various goals. The application of herbs in medicine is accompanied by harmful effects. Chick embryo is considered a suitable model for assessing drugs toxicity. The present study aimed to evaluate the changes in vasculature in chick's extra-embryonic membrane following D. ammoniacum treatment. Alterations in molecular pathways associated with early embryonic angiogenesis such as vascular endothelial growth factor A (VEGF-A) were also evaluated.

MATERIALS AND METHODS

Fertile chicken (Ross 308) eggs were allocated into three similar groups; sham, control and D. ammoniacum groups; in D. ammoniacum group, eggs were inoculated with plant's extract at doses of 50 or 100 mg per kg egg-weight.

RESULTS

Analysis of the extra-embryonic membrane vasculature revealed that D. ammoniacum extract decreases some vascular parameters such as vessels area, total vessels length, vascular branch and increases lacunarity. This herb's vascular toxicity was in a dose-dependent manner. Down-regulation of the expression of VEGF-A was also seen in the extract-treated extra-embryonic membrane.

CONCLUSION

Vascular toxicity of D. ammoniacum was confirmed by data presented in this paper. We conclude that alteration of vascular parameters and gene expression might finally lead to embryo malformation due to D. ammoniacum consumption. Therefore, the use of this herb must be limited during the fetal growth period especially at doses higher than 50 mg per kg.

Angiogenic factors during pregnancy in Asian women with elevated blood pressure in early pregnancy and the risk of preeclampsia: a longitudinal cohort study

OBJECTIVE

It remains unclear what roles placenta-originated angiogenic factors play in the pathogenesis of preeclampsia among hypertensive women. We compared maternal soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) levels throughout pregnancy in women with normal blood pressure (BP), elevated BP and hypertension in early pregnancy and their risks of developing preeclampsia.

DESIGN

A prospective cohort study.

SETTING

KK Women's and Children's Hospital, Singapore.

PARTICIPANTS

923 women with singleton pregnancy <14 weeks of gestation were included in the prospective Neonatal and Obstetrics Risks Assessment cohort between September 2010 and October 2014. Systolic, diastolic, mean arterial blood pressure (MAP) were measured at 11-14 weeks.

PRIMARY AND SECONDARY OUTCOMES

Maternal serum sFlt-1, PlGF and sFlt-1/PlGF ratio were tested at 11-14, 18-22, 28-32 and 34 weeks onwards of gestation. Preeclampsia was main pregnancy outcome.

RESULTS

Women were divided based on their BP in early pregnancy: normal (n=750), elevated BP (n=98) and hypertension (n=75). Maternal sFlt-1 levels and sFlt-1/PlGF ratios were higher in hypertensive women throughout pregnancy, but maternal PlGF levels were not significantly lower. Rise in maternal systolic, diastolic BP and MAP at 11-14 weeks were significantly associated with higher sFlt-1/PlGF ratios during pregnancy. A 10 mm Hg increase in MAP was associated with a 5.6-fold increase in risk of preterm preeclampsia and a 3.3-fold increase in risk of term preeclampsia, respectively.

CONCLUSION

Women with elevated BP in early pregnancy already had a higher sFlt-1/PlGF ratio in early gestation and throughout pregnancy, and an increased risk of preeclampsia. In contrast, PlGF levels in these women remained normal.

Recurrent intrauterine growth restriction: characteristic placental histopathological features and association with prenatal vascular Doppler

PURPOSE

Intrauterine growth restriction (IUGR) is a leading cause of perinatal morbidity and mortality, carrying a 20% recurrence rate. The placental disease is a cardinal factor among IUGR underlying processes. This study describes placental histopathological features (HPf) characteristic of recurrent IUGR (rIUGR) and assesses association with antenatal Doppler studies.

METHODS

We conducted a retrospective case-control study, between the years 2005-2016, evaluating 34 placentae of 17 women with rIUGR, and 59 placentae of a gestational age-matched control. Doppler studies within a week prior to delivery were analyzed for the rIUGR group.

RESULTS

Placental HPf characteristic of rIUGR is maternal and fetal vascular malperfusion lesions; maternal accelerated villous maturation and villous infarcts, repetitive feature rate 88.8% (95% CI 37.2-97), and fetal chorionic plate/stem villous thrombi, repetitive feature rate 66.6% (95% CI 30-90.3). Among women with abnormal Doppler, 83.3% had a placenta HPf of maternal vascular malperfusion lesions and 66.7% presented with a hypertensive disorder.

CONCLUSIONS

Women with rIUGR are a unique group of patients characterized by repetitive placental HPf of both maternal and fetal vascular malperfusion lesions. Specifically, maternal vascular malperfusion lesions are associated with abnormal Doppler findings. In conclusion, characteristic placental HPf may serve as predictors of future IUGR recurrence, thus offering early recognition of pregnancies that require "high-risk" antenatal care.

Predictive Performance of PlGF (Placental Growth Factor) for Screening Preeclampsia in Asymptomatic Women: A Systematic Review and Meta-Analysis

Preeclampsia is a systemic syndrome that seems to originate from the placenta and is associated with an imbalance between angiogenic factors in the maternal circulation. One of the well-studied and widely used factors is PlGF (placental growth factor), the levels of which drop in women destined to develop preeclampsia. This drop is known to precede the development of actual signs and symptoms of preeclampsia, thus proving to be a useful screening tool in predicting the disease. The literature varies widely in terms of the clinical usefulness of the test. We conducted a meta-analysis to study the predictive accuracy of PlGF in asymptomatic women. Our analysis included 40 studies with 3189 cases of preeclampsia and 89 498 controls. The overall predictive odds ratio of the test was 9 (6-13). Subgroup analysis evaluating various PlGF thresholds demonstrated that the predictive values were highest for PlGF levels between 80 and 120 pg/mL with a high predictive odds ratio of 25 (7-88), a sensitivity of 0.78 (95% CI, 0.67-0.86), a specificity of 0.88 (95% CI, 0.75-0.95), a positive likelihood ratio of 6.3 (95% CI, 2.7-14.7), and a negative likelihood ratio of 0.26 (95% CI, 0.16-0.42). Additionally, the accuracy was higher when the test was performed after 14 weeks of gestation (OR, 10 [7-15]) and for prediction of early onset preeclampsia (OR, 18 [9-37]). We conclude that PlGF is a useful screening tool to predict preeclampsia. Nonetheless, its utility should be judged with caution and randomized controlled trials are warranted to explore if its implementation improves perinatal outcomes in asymptomatic women.

A Review of Angiogenic Imbalance in HIV-Infected Hypertensive Disorders of Pregnancy

PURPOSE OF REVIEW

This review provides a comprehensive insight into the angiogenic profile of hypertensive and normotensive pregnancies compromised by HIV infection. Furthermore, we evaluate the economic implementation of the sFlt-1/PlGF ratio and review the reports on therapeutic apheresis in limiting sFlt-1 production.

RECENT FINDINGS

In preeclampsia, an increased expression of sFlt-1 triggers angiogenic imbalance. Women of African ancestry have high levels of angiogenic factors than other racial groups. The sFlt-1/PlGF ratio shows promise in the early assessment of preeclampsia, while sFlt-1 apheresis restores angiogenic imbalance. Studies suggest antiretroviral therapy does not impact the angiogenic shift in preeclampsia development. The angiogenic profile in pregnant women of different races influences preeclampsia development. Despite the opposing immune response in HIV infection and preeclampsia, the HIV tat protein strongly mimics vascular endothelial growth factor (VEGF); hence, it is plausible to assume that HIV infection may ameliorate the angiogenic imbalance in preeclampsia.

Pre-eclampsia: pathogenesis, novel diagnostics and therapies

Pre-eclampsia is a complication of pregnancy that is associated with substantial maternal and fetal morbidity and mortality. The disease presents with new-onset hypertension and often proteinuria in the mother, which can progress to multi-organ dysfunction, including hepatic, renal and cerebral disease, if the fetus and placenta are not delivered. Maternal endothelial dysfunction due to circulating factors of fetal origin from the placenta is a hallmark of pre-eclampsia. Risk factors for the disease include maternal comorbidities, such as chronic kidney disease, hypertension and obesity; a family history of pre-eclampsia, nulliparity or multiple pregnancies; and previous pre-eclampsia or intrauterine fetal growth restriction. In the past decade, the discovery and characterization of novel antiangiogenic pathways have been particularly impactful both in increasing understanding of the disease pathophysiology and in directing predictive and therapeutic efforts. In this Review, we discuss the pathogenic role of antiangiogenic proteins released by the placenta in the development of pre-eclampsia and review novel therapeutic strategies directed at restoring the angiogenic imbalance observed during pre-eclampsia. We also highlight other notable advances in the field, including the identification of long-term maternal and fetal risks conferred by pre-eclampsia.

Host's immune response in unresponsive and responsive patients with anthroponotic cutaneous leishmaniasis treated by meglumine antimoniate: A case-control study of Th1 and Th2 pathways

The objective of the present study was to compare the host's immune responses between unresponsive and responsive patients with anthroponotic cutaneous leishmaniasis (ACL) treated by meglumine antimoniate. A case-control study was carried out in an endemic focus in Iran. Blood samples were taken from patients and peripheral blood mononuclear cells (PBMCs) were isolated. Two wells were considered for each isolate of unresponsive and responsive patients; one was exposed to L. tropica (Lt-stimulated cells) and the other remained non-exposed (non-stimulated cells). After 24 h of incubation, whole RNA was extracted from each sample. Real-time quantitative PCR was carried out to confirm the differences in expression levels of IL-12 P40, IFN-γ, IL-1β, IL-4 and IL-10 among isolates. Data were analyzed and P < 0.05 was considered to be statistically significant. In our study, Lt-stimulated cells and non-stimulated cells in unresponsive groups demonstrated significantly lower expression levels of IL-1β, IL-12 P40 and IFN-γ genes and higher expression levels of IL-4 and IL-10 genes, compared to Lt-stimulated cells and non-stimulated cells in responsive groups. There was a negative correlation between IL-12 P40 with IL-10 and IL-1β with IL-10 in ACL Lt-stimulated cells in unresponsive group, while a positive correlation between IL-12 P40 with IL-1β and IL-12 P40 with IFN-γ in ACL Lt-stimulated cells in responsive group. Probably, different immune responses caused by various factors play a major role in the pathogenesis and development of unresponsiveness in ACL patients. The profile and timing of cytokine production correlated well with the treatment outcome of Leishmania infection.

Toxico-pathological effects of meglumine antimoniate on human umbilical vein endothelial cells

Leishmaniasis is one of the most important parasitic diseases after malaria. The standard treatment of leishmaniasis includes pentavalent antimonials (SbV); however, these drugs are associated with serious adverse effects. There have been very few studies pertaining to their side effects and mechanism of action in the fetus. This investigation examines the effects of meglumine antimoniate (MA) on the survival rate, angiogenesis and cellular apoptosis in the human umbilical vein endothelial cells (HUVECs). HUVECs were treated with varying doses of MA (100-800 μg/ml) for 24, 48 and 72 h and the survival rate was studied by colorimetric assay, flow cytometry, immunocytochemistry, migration (scratch) assay and tube formation assay. The results of quantitative real-time PCR (qPCR) studies indicated that the most important genes involved in presenting angiogenesis included VEGF and its receptors (Kdr and Flt-1), NP1 and Hif-1α genes including the anti-apoptotic gene of Bcl2, were significantly reduced compared to the control group (p < 0.05). In contrast, the most leading genes involved in the phenomenon of apoptosis were P53, Bax, Bak, Apaf-1 and caspases 3, 8 and 9, which were significantly up regulated compared to the control group (p < 0.05).

Placental growth factor as an indicator of fetal growth restriction in late-onset small-for-gestational age pregnancies

BACKGROUND

At-risk small-for-gestational age (SGA) pregnancies in New Zealand are identified using Doppler ultrasound; fetuses with Doppler abnormalities are considered growth restricted (FGR). Low maternal placental growth factor (PlGF) has also been associated with late-onset FGR.

AIMS

To investigate whether low PlGF at diagnosis of late-onset SGA identifies the same fetuses classified FGR by detailed Doppler studies, and the association between low PlGF and adverse pregnancy outcomes.

METHODS

Among an historical database of normotensive suspected SGA pregnancies (fetal abdominal circumference <10th percentile) ≥32 weeks gestation, the ability of low PlGF (<5th percentile) to identify FGR infants was investigated. 'Initial FGR' was an abnormal umbilical artery resistance index (RI) or estimated fetal weight <3rd customised centile. 'Secondary FGR' was abnormal internal carotid RI, cerebro-placental ratio and/or mean uterine artery RI. Development of hypertensive disease and adverse perinatal outcomes were compared by PlGF status.

RESULTS

Of 136 SGA pregnancies, 56 (41.1%) had initial FGR. Of the remaining, 20 (25.0%) had secondary FGR, 17 (21.3%) low PlGF. The sensitivity of low PlGF identifying secondary FGR was 0.30 (95% CI 0.14-0.50), specificity 0.83 (0.70-0.92), positive predictive value 0.47 (0.23-0.72) and negative predictive value 0.70 (0.57-0.81). Overall, low PlGF occurred in 44/136 (32.4%) pregnancies and was associated with gestational hypertensive disease (63.6% vs 15.2%, P < 0.01), adverse perinatal outcome (34.1% vs 15.2%, P = 0.01) and very low birthweight (customised centile 2.2 vs 6.8, P < 0.01).

CONCLUSIONS

At diagnosis of late-onset SGA, low PlGF was poor at identifying Doppler-defined FGR. Low PlGF identified pregnancies at risk of hypertensive disease, adverse perinatal outcome and very low birthweight.

Infant size and the association between maternal circulating angiogenic factors and preeclampsia

OBJECTIVE

To assess the effect of infant size as a marker of placental function on the association between preeclampsia and the ratio of soluble fms-like tyrosine kinase 1 (sFlt-1) to placental growth factor (PlGF).

STUDY DESIGN

The angiogenic factors sFlt-1 and PlGF were measured prospectively at 26 weeks gestation in 2322 women. Pregnancies were stratified by whether or not they were complicated by preeclampsia, the timing of delivery, and birthweight Z-score.

RESULT

Independent of preeclampsia status, women with small infants (Z < -1.0) have an increased sFlt-1/PlGF ratio, and women with large infants (Z > 1.0) have a decreased ratio. Among pregnancies yielding small infants, the sFlt-1/PlGF ratio is markedly elevated in preeclamptic pregnancies requiring delivery before 37 weeks (110.0 vs. 17.9, p < 0.0001) but not in preeclamptic pregnancies delivered at term. The strength of the association between preeclampsia and the sFlt-1/PlGF ratio is increased for small infants compared to normal-sized or large infants.

CONCLUSION

The sFlt-1/PlGF ratio in the late second trimester is similarly elevated in women with preeclampsia and in women with small infant size and more markedly elevated in a syndrome of placental dysfunction characterized by preeclampsia, preterm delivery, and growth restriction.

Genetic predisposition to preeclampsia is conferred by fetal DNA variants near FLT1, a gene involved in the regulation of angiogenesis

Preeclampsia risk is influenced by both the mother's genetic background and the genetics of her fetus; however, the specific genes responsible for conferring preeclampsia risk have largely remained elusive. Evidence that preeclampsia has a genetic predisposition was first detailed in the early 1960s, and overall preeclampsia heritability is estimated at ∼55%. Many traditional gene discovery approaches have been used to investigate the specific genes that contribute to preeclampsia risk, but these have largely not been successful or reproducible. Over the past decade, genome-wide association studies have allowed for significant advances in the understanding of the genetic basis of many common diseases. Genome-wide association studies are predicated on the idea that the genetic basis of many common diseases are complex and polygenic with many variants, each with modest effects that contribute to disease risk. Using this approach in preeclampsia, a large genome-wide association study recently identified and replicated the first robust fetal genomic region associated with excess risk. A screen of >7 million genetic variants in 2658 offspring from preeclamptic women and 308,292 population controls identified a single association signal close to the Fms-like tyrosine kinase 1 gene, on chromosome 13. Fms-like tyrosine kinase 1 encodes soluble Fms-like tyrosine kinase 1, a splice variant of the vascular endothelial growth factor receptor that exerts antiangiogenic activity by inhibiting signaling of proangiogenic factors. The Fms-like tyrosine kinase 1 pathway is central in preeclampsia pathogenesis because excess circulating soluble Fms-like tyrosine kinase 1 in the maternal plasma leads to the hallmark clinical features of preeclampsia, including hypertension and proteinuria. The success of this landmark fetal preeclampsia genome-wide association study suggests that well-powered, larger maternal and fetal genome-wide association study will be fruitful in identifying additional common variants that implicate causal preeclampsia genes and pathways. Such efforts will rely on the continued development of large preeclampsia consortia focused on preeclampsia genetics to obtain adequate sample sizes, detailed clinical phenotyping, and matched maternal-fetal samples. In summary, the fetal preeclampsia genome-wide association study represents an exciting advance in preeclampsia biology, suggesting that dysregulation at the Fms-like tyrosine kinase 1 locus in the fetal genome (likely in the placenta) is a fundamental molecular defect in preeclampsia.

The profiles of soluble adhesion molecules in the "great obstetrical syndromes". J Matern Fetal Neonatal Med 2018;32:2113-2136. [PMID: 29320948 DOI: 10.1080/14767058.2018.1427058]

OBJECTIVE

The objective of this study was to determine the profiles of maternal plasma soluble adhesion molecules in patients with preeclampsia, small-for-gestational-age (SGA) fetuses, acute pyelonephritis, preterm labor with intact membranes (PTL), preterm prelabor rupture of the membranes (preterm PROM), and fetal death.

MATERIALS AND METHODS

A cross-sectional study was conducted to determine maternal plasma concentrations of sE-selectin, sL-selectin, and sP-selectin as well as sICAM-1, sVCAM-1, and sPECAM-1 in patients with (1) an uncomplicated pregnancy (control, n = 100); (2) preeclampsia (n = 94); (3) SGA fetuses (in women without preeclampsia/hypertension, n = 45); (4) acute pyelonephritis (n = 25); (5) PTL (n = 53); (6) preterm PROM (n = 24); and (7) fetal death (n = 34). Concentrations of soluble adhesion molecules and inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-8) were determined with sensitive and specific enzyme-linked immunoassays.

RESULTS

In comparison to women with a normal pregnancy, (1) women with preeclampsia had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1, and a lower concentration of sL-selectin (all p values < .001); (2) patients with SGA fetuses had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1 (all p values < .05); (3) patients with a fetal death had higher median concentrations of sE-selectin and sP-selectin (all p values < .05); (4) patients with acute pyelonephritis had higher median plasma concentrations of sE-selectin, sICAM-1, and sVCAM-1 (all p values < .001); (5) patients with preeclampsia and acute pyelonephritis, plasma concentrations of sVCAM-1, sE-selectin, and sP-selectin correlated with those of the proinflammatory cytokines TNF-α and interleukin (IL)-8 (all p values < .05); (6) patients with PTL had a higher median concentration of sP-selectin and a lower median concentration of VCAM-1 (all p values < .05); and (7) women with preterm PROM had lower median concentrations of sL-selectin and sVCAM-1 (all p values < .05).

CONCLUSIONS

The results of this study show that endothelial cell activation/dysfunction reflected by the plasma concentration of sE-selectin is not specific to preeclampsia but is present in pregnancies complicated by SGA fetuses, acute pyelonephritis, and fetal death. Collectively, we report that each obstetrical syndrome appears to have a stereotypical profile of soluble adhesion molecules in the peripheral circulation.

MicroRNA-30a-3p is overexpressed in the placentas of patients with preeclampsia and affects trophoblast invasion and apoptosis by its effects on IGF-1

OBJECTIVE

Preeclampsia (PE) affects many women globally and remains a primary cause of neonatal and maternal morbidity and mortality. Aberrant placental microRNA (miRNA) expression might be associated with PE. Previously, 33 PE-related miRNAs, 11 up-regulated and 23 down-regulated, were detected in placentas of women with severe PE when compared with those of normal patients. One of the most up-regulated miRNAs in PE is miR-30a-3p. The predicted target of it is insulin-like growth factor 1 (IGF-1), which has been reported to have a relatively low expression level in PE patients. This study was conducted to determine the aberrant increased of miR-30a-3p in the placentas of women with preeclampsia and to elucidate the target and function of it in trophoblast cells.

STUDY DESIGN

miR-30a-3p expression in placenta tissues was compared between women with preeclampsia (n = 25) and normal pregnant women (n = 20). The miRNA target was studied by in silico and functional assay. The effects of the miRNA were verified by apoptosis assay and invasion assay in the trophoblast cell line.

RESULTS

miR-30a-3p was increased significantly in the placenta of women with preeclampsia when compared to those with normal pregnancies. Luciferase assay confirmed direct regulation of miR-30a-3p on the expression of IGF-1. Forced expression of miR-30a-3p suppressed IGF-1 protein expression in the HTR-8/SVneo cells. The functional assay suggests that the over-expression of miR-30a-3p alter the invasive capacity of JEG-3 cells and induce the apoptosis of HTR-8/SVneo cells (Figure).

CONCLUSION

Expression of miR-30a-3p was significantly increased in the placentas of patients with preeclampsia. miR-30a-3p might be involved in the pathogenesis of preeclampsia by targeting IGF-1 and regulating the invasion and apoptosis of trophoblast cells.

The prediction of fetal death with a simple maternal blood test at 20-24 weeks: a role for angiogenic index-1 (PlGF/sVEGFR-1 ratio)

BACKGROUND

Fetal death is an obstetrical syndrome that annually affects 2.4 to 3 million pregnancies worldwide, including more than 20,000 in the United States each year. Currently, there is no test available to identify patients at risk for this pregnancy complication.

OBJECTIVE

We sought to determine if maternal plasma concentrations of angiogenic and antiangiogenic factors measured at 24-28 weeks of gestation can predict subsequent fetal death.

STUDY DESIGN

A case-cohort study was designed to include 1000 randomly selected subjects and all remaining fetal deaths (cases) from a cohort of 4006 women with a singleton pregnancy, enrolled at 6-22 weeks of gestation, in a pregnancy biomarker cohort study. The placentas of all fetal deaths were histologically examined by pathologists who used a standardized protocol and were blinded to patient outcomes. Placental growth factor, soluble endoglin, and soluble vascular endothelial growth factor receptor-1 concentrations were measured by enzyme-linked immunosorbent assays. Quantiles of the analyte concentrations (or concentration ratios) were estimated as a function of gestational age among women who delivered a live neonate but did not develop preeclampsia or deliver a small-for-gestational-age newborn. A positive test was defined as analyte concentrations (or ratios) <2.5th and 10th centiles (placental growth factor, placental growth factor/soluble vascular endothelial growth factor receptor-1 [angiogenic index-1] and placental growth factor/soluble endoglin) or >90th and 97.5th centiles (soluble vascular endothelial growth factor receptor-1 and soluble endoglin). Inverse probability weighting was used to reflect the parent cohort when estimating the relative risk.

RESULTS

There were 11 fetal deaths and 829 controls with samples available for analysis between 24-28 weeks of gestation. Three fetal deaths occurred <28 weeks and 8 occurred ≥28 weeks of gestation. The rate of placental lesions consistent with maternal vascular underperfusion was 33.3% (1/3) among those who had a fetal death <28 weeks and 87.5% (7/8) of those who had this complication ≥28 weeks of gestation. The maternal plasma angiogenic index-1 value was <10th centile in 63.6% (7/11) of the fetal death group and in 11.1% (92/829) of the controls. The angiogenic index-1 value was <2.5th centile in 54.5% (6/11) of the fetal death group and in 3.7% (31/829) of the controls. An angiogenic index-1 value <2.5th centile had the largest positive likelihood ratio for predicting fetal death >24 weeks (14.6; 95% confidence interval, 7.7-27.7) and a relative risk of 29.1 (95% confidence interval, 8.8-97.1), followed by soluble endoglin >97.5th centile and placental growth factor/soluble endoglin <2.5th, both with a positive likelihood ratio of 13.7 (95% confidence interval, 7.3-25.8) and a relative risk of 27.4 (95% confidence interval, 8.2-91.2). Among women without a fetal death whose plasma angiogenic index-1 concentration ratio was <2.5th centile, 61% (19/31) developed preeclampsia or delivered a small-for-gestational-age neonate; when the 10th centile was used as the cut-off, 37% (34/92) of women had these adverse outcomes.

CONCLUSION

(1) A maternal plasma angiogenic index-1 value <2.5th centile (0.126) at 24-28 weeks of gestation carries a 29-fold increase in the risk of subsequent fetal death and identifies 55% of subsequent fetal deaths with a false-positive rate of 3.5%; and (2) 61% of women who have a false-positive test result will subsequently experience adverse pregnancy outcomes.

Serum Angiogenic and Anti-angiogenic Markers in Pregnant Women with Placenta Percreta

BACKGROUND

Placenta percreta is the morbidly adherent form of all the placental invasion abnormalities. The pathology that underlies placenta percreta is poorly understood.

AIMS

To compare the levels of circulating vascular endothelial growth factor, placental growth factor and soluble fms-like tyrosine kinase 1 in pregnant women with placenta percreta to a control group.

STUDY DESIGN

Case-control study.

METHODS

Twenty-two women who underwent caesarean section due to placenta percreta and 22 women who underwent caesarean section for other obstetric reasons were included in this study. The diagnosis of placenta percreta was defined as extreme trophoblastic invasion involving serosa of the uterus. Venous blood samples were collected for biochemical comparison of circulating vascular endothelial growth factor, placental growth factor and soluble fms-like tyrosine kinase 1 from all pregnant women.

RESULTS

Women with placenta percreta were significantly older, had higher gravidity, received more frequent antenatal steroids and blood transfusions and delivered at an earlier gestational age when compared to the control group. In women with placenta percreta, preoperative circulating levels of vascular endothelial growth factor, placental growth factor and soluble fms-like tyrosine kinase 1 were lower than the controls (p<0.001, p<0.001 and p<0.05, respectively). While the postoperative levels of vascular endothelial growth factorand soluble fms-like tyrosine kinase 1 levels were higher in placenta percreta (p=0.001 and p<0.001, respectively), placental growth factor levels were similar in both groups.

CONCLUSION

The findings of this study suggest that a decrease in vascular endothelial growth factor, placental growth factor and soluble fms-like tyrosine kinase 1 levels may be related to placenta percreta etiopathogenesis.

The role of angiogenic markers in adverse perinatal outcomes: fresh versus frozen embryo transfers

PURPOSE

We aimed to investigate the angiogenic balance in fresh compared to frozen embryo transfers, and among neonates with adverse perinatal outcomes.

METHODS

This was a retrospective cohort study. All IVF cycles resulting in a singleton live birth at a university academic fertility center from January 1, 2011, to December 31, 2013, were examined. Concentrations of sFLT-1 and PlGF were measured in previously frozen serum specimens collected during early gestation at approximately 5 weeks gestation. Patients completed an electronic survey to detail perinatal outcome.

RESULTS

We identified 152 singleton live births (103 fresh, 49 frozen). Demographic characteristics were similar between the two groups. Ratios of sFlt-1:PlGF were not different between fresh and frozen transfers. Neonates from fresh cycles had a mean birth weight 202 g lighter (p = 0.01) than frozen cycles, after adjusting for gestational age. Among babies born with poor perinatal outcomes, there was a difference in sFlt-1:PlGF ratios after adjusting for race. In non-Asians, infants born small for gestational age (SGA) (< 10th percentile) had significantly higher sFLT-1:PLGF ratio, median ratio (0.21 vs 0.12, p = 0.016).

CONCLUSIONS

Fresh transfers were associated with lower birth weight infants compared to frozen transfers. While there was no difference in sFlt-1:PlGF ratios between fresh and frozen transfers, these ratios were significantly lower in SGA infants, suggesting an imbalance in angiogenic markers during placentation.

Metformin, the aspirin of the 21st century: its role in gestational diabetes mellitus, prevention of preeclampsia and cancer, and the promotion of longevity

Metformin is everywhere. Originally introduced in clinical practice as an antidiabetic agent, its role as a therapeutic agent is expanding to include treatment of prediabetes mellitus, gestational diabetes mellitus, and polycystic ovarian disease; more recently, experimental studies and observations in randomized clinical trials suggest that metformin could have a place in the treatment or prevention of preeclampsia. This article provides a brief overview of the history of metformin in the treatment of diabetes mellitus and reviews the results of metaanalyses of metformin in gestational diabetes mellitus as well as the treatment of obese, non-diabetic, pregnant women to prevent macrosomia. We highlight the results of a randomized clinical trial in which metformin administration in early pregnancy did not reduce the frequency of large-for-gestational-age infants (the primary endpoint) but did decrease the frequency of preeclampsia (a secondary endpoint). The mechanisms by which metformin may prevent preeclampsia include a reduction in the production of antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 and soluble endoglin) and the improvement of endothelial dysfunction, probably through an effect on the mitochondria. Another potential mechanism whereby metformin may play a role in the prevention of preeclampsia is its ability to modify cellular homeostasis and energy disposition, mediated by rapamycin, a mechanistic target. Metformin has a molecular weight of 129 Daltons and therefore readily crosses the placenta. There is considerable evidence to suggest that this agent is safe during pregnancy. New literature on the role of metformin as a chemotherapeutic adjuvant in the prevention of cancer and in prolonging life and protecting against aging is reviewed briefly. Herein, we discuss the mechanisms of action and potential benefits of metformin.

The prediction of late-onset preeclampsia: Results from a longitudinal proteomics study

BACKGROUND

Late-onset preeclampsia is the most prevalent phenotype of this syndrome; nevertheless, only a few biomarkers for its early diagnosis have been reported. We sought to correct this deficiency using a high through-put proteomic platform.

METHODS

A case-control longitudinal study was conducted, including 90 patients with normal pregnancies and 76 patients with late-onset preeclampsia (diagnosed at ≥34 weeks of gestation). Maternal plasma samples were collected throughout gestation (normal pregnancy: 2-6 samples per patient, median of 2; late-onset preeclampsia: 2-6, median of 5). The abundance of 1,125 proteins was measured using an aptamers-based proteomics technique. Protein abundance in normal pregnancies was modeled using linear mixed-effects models to estimate mean abundance as a function of gestational age. Data was then expressed as multiples of-the-mean (MoM) values in normal pregnancies. Multi-marker prediction models were built using data from one of five gestational age intervals (8-16, 16.1-22, 22.1-28, 28.1-32, 32.1-36 weeks of gestation). The predictive performance of the best combination of proteins was compared to placental growth factor (PIGF) using bootstrap.

RESULTS

1) At 8-16 weeks of gestation, the best prediction model included only one protein, matrix metalloproteinase 7 (MMP-7), that had a sensitivity of 69% at a false positive rate (FPR) of 20% (AUC = 0.76); 2) at 16.1-22 weeks of gestation, MMP-7 was the single best predictor of late-onset preeclampsia with a sensitivity of 70% at a FPR of 20% (AUC = 0.82); 3) after 22 weeks of gestation, PlGF was the best predictor of late-onset preeclampsia, identifying 1/3 to 1/2 of the patients destined to develop this syndrome (FPR = 20%); 4) 36 proteins were associated with late-onset preeclampsia in at least one interval of gestation (after adjustment for covariates); 5) several biological processes, such as positive regulation of vascular endothelial growth factor receptor signaling pathway, were perturbed; and 6) from 22.1 weeks of gestation onward, the set of proteins most predictive of severe preeclampsia was different from the set most predictive of the mild form of this syndrome.

CONCLUSIONS

Elevated MMP-7 early in gestation (8-22 weeks) and low PlGF later in gestation (after 22 weeks) are the strongest predictors for the subsequent development of late-onset preeclampsia, suggesting that the optimal identification of patients at risk may involve a two-step diagnostic process.

The maternal plasma proteome changes as a function of gestational age in normal pregnancy: a longitudinal study

OBJECTIVE

Pregnancy is accompanied by dramatic physiological changes in maternal plasma proteins. Characterization of the maternal plasma proteome in normal pregnancy is an essential step for understanding changes to predict pregnancy outcome. The objective of this study was to describe maternal plasma proteins that change in abundance with advancing gestational age and determine biological processes that are perturbed in normal pregnancy.

STUDY DESIGN

A longitudinal study included 43 normal pregnancies that had a term delivery of an infant who was appropriate for gestational age without maternal or neonatal complications. For each pregnancy, 3 to 6 maternal plasma samples (median, 5) were profiled to measure the abundance of 1125 proteins using multiplex assays. Linear mixed-effects models with polynomial splines were used to model protein abundance as a function of gestational age, and the significance of the association was inferred via likelihood ratio tests. Proteins considered to be significantly changed were defined as having the following: (1) >1.5-fold change between 8 and 40 weeks of gestation; and (2) a false discovery rate-adjusted value of P < .1. Gene ontology enrichment analysis was used to identify biological processes overrepresented among the proteins that changed with advancing gestation.

RESULTS

The following results were found: (1) Ten percent (112 of 1125) of the profiled proteins changed in abundance as a function of gestational age; (2) of the 1125 proteins analyzed, glypican-3, sialic acid-binding immunoglobulin-type lectin-6, placental growth factor, C-C motif-28, carbonic anhydrase 6, prolactin, interleukin-1 receptor 4, dual-specificity mitogen-activated protein kinase 4, and pregnancy-associated plasma protein-A had more than a 5-fold change in abundance across gestation (these 9 proteins are known to be involved in a wide range of both physiological and pathological processes, such as growth regulation, embryogenesis, angiogenesis immunoregulation, inflammation etc); and (3) biological processes associated with protein changes in normal pregnancy included defense response, defense response to bacteria, proteolysis, and leukocyte migration (false discovery rate, 10%).

CONCLUSION

The plasma proteome of normal pregnancy demonstrates dramatic changes in both the magnitude of changes and the fraction of the proteins involved. Such information is important to understand the physiology of pregnancy and the development of biomarkers to differentiate normal vs abnormal pregnancy and determine the response to interventions.

Biomarkers for Adverse Pregnancy Outcomes in Rheumatic Diseases

Pregnancy is a delicate balance of angiogenic factors. Adverse pregnancy outcomes in the form of placental insufficiency occur when antiangiogenic factors predominate, which manifests as maternal-placental syndrome (MPS). Women with rheumatic disease are at increased risk of MPS. Endothelial damage from circulating antiangiogenic factors and other inflammatory molecules in combination with preexisting maternal vascular risk factors is the likely underlying pathophysiological process for MPS. It is likely that these changes persist, and additional "insults" from ongoing inflammation, medications, and disease damage contribute to the development of accelerated cardiovascular disease seen in young women with rheumatic disease.

Maternal plasma-soluble ST2 concentrations are elevated prior to the development of early and late onset preeclampsia - a longitudinal study

OBJECTIVE

The objectives of this study were to determine (1) the longitudinal profile of plasma soluble ST2 (sST2) concentrations in patients with preeclampsia and those with uncomplicated pregnancies; (2) whether the changes in sST2 occur prior to the diagnosis of preeclampsia; and (3) the longitudinal sST2 profile of women with early or late preeclampsia.

MATERIALS AND METHODS

This longitudinal nested case-control study included singleton pregnancies in the following groups: (1) uncomplicated pregnancies (n = 160); and (2) those complicated by early (<34 weeks, n = 9) and late (≥34 weeks, n = 31) preeclampsia. sST2 concentrations were determined by enzyme-linked immunosorbent assays. Mixed-effects models were used for the longitudinal analysis.

RESULTS

(1) Plasma sST2 concentration profiles across gestation differed significantly among cases and controls (p < 0.0001); (2) women with early preeclampsia had higher mean sST2 concentrations than controls at >22 weeks of gestation; cases with late preeclampsia had higher mean concentrations at >33 weeks of gestation (both p < 0.05); and (3) these changes started approximately 6 weeks prior to clinical diagnosis.

CONCLUSIONS

Maternal plasma sST2 concentrations are elevated 6 weeks prior to the clinical diagnosis of preeclampsia. An increase in the maternal plasma concentration of sST2 may contribute to an exaggerated intravascular inflammatory response and/or the Th1/Th2 imbalance in some cases.

Placental soluble fms-like tyrosine kinase expression in small for gestational age infants and risk for adverse outcomes

INTRODUCTION

Soluble fms-like tyrosine kinase 1 (sFLT-1) is an anti-angiogenic factor implicated in the pathogenesis of preterm preeclampsia. We evaluated sFLT-1 expression and placental pathology in pregnancies complicated by small for gestational age (SGA) infants (<10th percentile), without evidence of preeclampsia.

METHODS

Clinical and histologic data were compared between groups with high or low sFLT-1 expression determined by immunohistochemistry on archived placentas.

RESULTS

Nineteen of 69 placentas showed high sFLT-1 expression. The high sFLT-1 group had higher predelivery median systolic blood pressure (BP); 140 (interquartile range (IQR) 133-152) vs. 126 (118-139) mm Hg (p = 0.003), and median diastolic BP; 87 (78-94) vs. 77.5 (71-86) mm Hg (p = 0.02). Abnormal umbilical Doppler abnormalities were more prevalent; 89.5% vs. 46% (p = 0.001). These pregnancies delivered earlier; 31.9 weeks (28.3-34.7 weeks) vs. 37.1 weeks (33.7-38.7 weeks) (p < 0.001), and infants had lower birthweight; 980 grams (520-1545 grams) vs. 2087.5 grams (1455-2340 grams) (p < 0.001). Placental-weight to fetal-weight ratios, a marker of vascular insufficiency, was increased in the high sFlt-1 group: 0.18 (0.14-0.28) vs 0.15 (0.13-0.18), p = 0.03. Placentas with high sFLT-1 showed more decidual vasculopathy; 42.1% vs. 10.0% (p = 0.005), infarction; 36.8% vs. 14.0% (p = 0.048), distal villous hypoplasia; 78.9% vs. 36.0% (p = 0.001), and fetal thrombotic vasculopathy; 47.4% vs. 16.0% (p = 0.01).

DISCUSSION

Placental sFLT-1 expression is upregulated in approximately 28% of non-preeclamptic pregnancies complicated by SGA infants. These pregnancies showed increased placental vascular pathology, more umbilical Doppler abnormalities, and earlier delivery with lower birthweight. A subgroup of non-preeclamptic fetal growth restriction with upregulated sFlt-1 expression may share a common pathogenic pathway with preterm preeclampsia. This subgroup is worthy of additional study.