Angiogenic factors and the risk of preeclampsia: A systematic review and meta-analysis

Relationship between serum uric acid, nocturnal hypertension and risk for preeclampsia in high-risk pregnancies

To analyze the possible association between serum uric acid (SUA) and nocturnal hypertension and to evaluate the ability of these variables (alone or in combination) to predict preeclampsia (PE) we conducted a historical cohort study in 532 high-risk pregnancies. Women were divided according to SUA values and nocturnal blood pressure (BP) into four groups: 1- normal SUA and nocturnal normotension; 2- high SUA and nocturnal normotension; 3- normal SUA and nocturnal hypertension and 4- high SUA and nocturnal hypertension. High SUA was defined by the top quartile values and nocturnal hypertension as BP ≥ 120/70 mmHg, using ambulatory blood pressure monitoring (ABPM), during nocturnal rest. Risks for PE were compared using logistic regression. SUA had a weak but significant correlation with daytime systolic ABPM (r = 0.11, p = 0.014), daytime diastolic ABPM (r = 0.13, p = 0.004), nighttime systolic ABPM (r = 0.16, p < 0.001) and nighttime diastolic ABPM (r = 0.18, p < 0.001). Also, all ABPM values were higher in women with high SUA. The absolute risk of PE increased through groups: 6.5%, 13.1%, 31.2%, and 47.9% for groups 1, 2, 3, and 4, respectively, p < 0.001. Compared with Group 1, Group 3 (OR 6.29 95%CI 3.41-11.60), but not Group 2 (OR 2.15 95%CI 0.88-5.24), had statistically significant higher risk for PE. Group 4 (women with both, high SUA and nocturnal hypertension) had the highest risk (OR 13.11 95%CI 6.69-25.70). Risks remained statistically significant after the adjustment for relevant variables. In conclusion, the combination of SUA > 4 mg/dL and nocturnal BP > 120/70 mmHg implies a very high risk to developed PE.

Early Fetal Growth Restriction with or Without Hypertensive Disorders: a Clinical Overview

Early onset fetal growth restriction (FGR) is one of the main adverse pregnancy conditions, often associated with poor neonatal outcomes. Frequently, early onset FGR is associated with early onset hypertensive disorders of pregnancy (HDP), and in particular preeclampsia (PE). However, to date, it is still an open question whether pregnancies complicated by early FGR plus HDP (FGR-HDP) and those complicated by early onset FGR without HDP (normotensive-FGR (n-FGR)) show different prenatal and postnatal outcomes and, consequently, should benefit from different management and long-term follow-up. Recent data support the hypothesis that the presence of PE may have an additional impact on maternal hemodynamic impairment and placental lesions, increasing the risk of poor neonatal outcomes in pregnancy affected by early onset FGR-HDP compared to pregnancy affected by early onset n-FGR. This review aims to elucidate this poor studied topic, comparing the clinical characteristics, perinatal outcomes, and potential long-term sequelae of early onset FGR-HDP and early onset n-FGR.

Pre-eclampsia

Pre-eclampsia is a life-threatening disease of pregnancy unique to humans and a leading cause of maternal and neonatal morbidity and mortality. Women who survive pre-eclampsia have reduced life expectancy, with increased risks of stroke, cardiovascular disease and diabetes, while babies from a pre-eclamptic pregnancy have increased risks of preterm birth, perinatal death and neurodevelopmental disability and cardiovascular and metabolic disease later in life. Pre-eclampsia is a complex multisystem disease, diagnosed by sudden-onset hypertension (>20 weeks of gestation) and at least one other associated complication, including proteinuria, maternal organ dysfunction or uteroplacental dysfunction. Pre-eclampsia is found only when a placenta is or was recently present and is classified as preterm (delivery <37 weeks of gestation), term (delivery ≥37 weeks of gestation) and postpartum pre-eclampsia. The maternal syndrome of pre-eclampsia is driven by a dysfunctional placenta, which releases factors into maternal blood causing systemic inflammation and widespread maternal endothelial dysfunction. Available treatments target maternal hypertension and seizures, but the only 'cure' for pre-eclampsia is delivery of the dysfunctional placenta and baby, often prematurely. Despite decades of research, the aetiology of pre-eclampsia, particularly of term and postpartum pre-eclampsia, remains poorly defined. Significant advances have been made in the prediction and prevention of preterm pre-eclampsia, which is predicted in early pregnancy through combined screening and is prevented with daily low-dose aspirin, starting before 16 weeks of gestation. By contrast, the prediction of term and postpartum pre-eclampsia is limited and there are no preventive treatments. Future research must investigate the pathogenesis of pre-eclampsia, in particular of term and postpartum pre-eclampsia, and evaluate new prognostic tests and treatments in adequately powered clinical trials.

An observational study of pro- and anti-angiogenic factors in hypertensive disorders of pregnancy in women of African ancestry

Hypertensive disorders in pregnancy (HDPs) are the leading cause of maternal and perinatal deaths worldwide. Despite the widely reported multisystemic pathophysiology of pre-eclampsia and other HDPs, it is unknown whether these disorders represent a continuum or separate entities making clinical diagnosis a challenge. This study aimed to investigate angiogenic, metabolic and immunoregulatory specific profiles of hypertensive and gestationally matched normotensive pregnancies. A total of 200 pregnancies from a regional hospital in South Africa, via convenience sampling, were quantitatively analysed for circulating sFlt-1; PlGF; VEGF; sENG; PAPP-A; PP13; ADAMTS 12; TGF-β1 in maternal serum samples using ELISA technique. Serum protein markers TGF-β1, sENG and PAPP-A were significantly increased (p < .05) in early-onset pre-eclampsia vs. NG1 groups. sFlt-1 was significantly higher in late-onset pre-eclampsia vs NG2 groups. The GH group showed a significant increase in TGF-β1 and PAPP-A vs. NG1 counterpart. ADAMTS12 and sENG were significantly lower in gestational hypertension vs. early-onset pre-eclampsia. No significant differences were seen in PlGF, VEGF and PP13 levels across the groups. These changes show the HDP spectrum has distinct characteristics on the angiogenic profile. Based on these results, further validation of diagnostic and prognostic biomarkers of pre-eclampsia and gestational hypertension is warranted.Impact statementWhat is already known on this subject? Hypertensive pregnancy disorders are a public health problem with adverse effects on both mother and neonate. The elusive pathogenesis of this syndrome combined with the late prevalence of symptoms leaves clinicians with a myriad of theories and indefinite treatments. The investigation into conventional anti-/angiogenic factors has been extensively studied in pre-eclampsia patients only. The overlapping clinical presentation of pre-eclampsia and gestational hypertension further complicates the diagnosis of disorders.What do the results of this study add? The investigation of novel angiogenic, metabolic and inflammatory markers will firstly contribute to generating a database for researchers both nationally and internationally. This combinatory triad of markers will assist in elucidating and differentiating between early- and late-onset preeclampsia versus gestational hypertension. The results of our cohort study suggest possible early diagnostic markers for pre-eclampsia and gestational hypertension.What are the implications of these findings for clinical practice and/or further research? Research in this area will contribute to an improvement in early disease management which will ultimately lead to a reduction in health care costs and mortality rate locally and globally. It will also enforce diagnostic and prognostic markers for hypertensive pregnancy diseases and warrant further investigation into the proteins primarily involved in the trophoblastic invasion. This will then clarify whether these two closely related hypertensive disorders represent a continuum or two separate entities.

Hematobiochemical variability and predictors of new-onset and persistent postpartum preeclampsia

Preeclampsia (PE) can occur antepartum or postpartum. When it develops de novo after childbirth, it is termed new-onset postpartum PE (NOPPE). Often, antepartum PE disappears after childbirth; however, in some women it persists after childbirth. This form of PE is termed persistent PE (PPE). Thus, there are two forms of postpartum PE: NOPPE and PPE. The pathogenesis and pathophysiology of these diseases have not been fully characterized, and whether NOPPE and PPE are different or similar pathological conditions remains unexplored. Thus, we aimed to compare the haematological and biochemical characteristics of NOPPE and PPE, predict the occurrence of new-onset PE and identify lifestyles that predispose women to postpartum PE. A total of 130 women comprising 65 normotensive postpartum women, 33 NOPPE and 32 PPE women were recruited for this hospital-based case-control study. The socio-demographic and lifestyle characteristics of the participants were obtained through well-structured questionnaires. Haematological and biochemical indices were measured using automated analysers and ELISA. The prevalence of postpartum PE was 11.9%. Dyslipidaemia (p =  < 0.0001), hypomagnesaemia (p =  < 0.001), elevated serum levels of ALT, AST (p =  < 0.0001), sVCAM-1 (p =  < 0.0001) and sFlt-1 (p =  < 0.0001) were more prevalent and severe in the PPE than in the NOPPE. Sedentary lifestyle was common among both groups of hypertensive women. Elevated ALT and AST were significant predictors of NOPPE. These findings indicate that preeclampsia exists after childbirth in a high percentage of women. NOPPE and PPE are different pathological conditions that require different clinical management. Combined glucose, lipid and liver assessment could be useful in predicting postpartum PE.

Maternal Levels of Perfluoroalkyl Substances (PFAS) during Early Pregnancy in Relation to Preeclampsia Subtypes and Biomarkers of Preeclampsia Risk

BACKGROUND

Prenatal exposure to perfluoroalkyl substances (PFAS) has been previously associated with preeclampsia, although findings are mixed with respect to the direction and magnitude of effect. To our knowledge, no studies have examined associations between PFAS and preeclampsia subtypes, which may have distinct etiologies.

OBJECTIVE

We examined associations between PFAS, any preeclampsia diagnosis, and early- and late-onset preeclampsia. In addition, we estimated associations between PFAS and the angiogenic biomarkers soluble fms-like tyrosine kinase-1 (sFLT-1) and placental growth factor (PlGF), which provide an estimate of pro- and anti-angiogenic activity within the placenta.

METHODS

This case-control study (n=75 cases, n=75 controls) was sampled from the LIFECODES birth cohort. Nine legacy PFAS were quantified in maternal plasma from early pregnancy (median= 10 wk) and angiogenic biomarkers were quantified in maternal plasma from four study visits (median= 10, 18, 26, and 35 wk). Logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of the association between an interquartile range (IQR)-increase in PFAS and preeclampsia outcomes. Linear regression was used to estimate associations between an IQR-increase in PFAS and concentrations of angiogenic biomarkers.

RESULTS

Both perfluorodecanoic acid (OR= 1.64, 95% CI: 1.08, 2.47) and perfluorooctanesulfonic acid (OR= 1.60, 95% CI: 1.06, 2.43) were associated with higher odds of late-onset preeclampsia. Associations tended to be below the null for early-onset preeclampsia, although findings were imprecise. Few associations were noted between PFAS and angiogenic biomarkers.

DISCUSSION

Maternal PFAS concentrations were associated with higher odds of late-onset preeclampsia. Heterogeneity of preeclampsia should be considered in future studies because populations may have different distributions of disease subtypes. https://doi.org/10.1289/EHP9091.

Reduction of serum-induced endothelial STAT3(Y705) activation is associated with preeclampsia

OBJECTIVES

Preeclampsia is associated with maternal morbidity and mortality during pregnancy, and also an increased cardiovascular disease (CVD) risk later in life. During preeclampsia, alterations in secreted placental factors leading to systemic maternal endothelial dysfunction are evident. However, little is known about the associated endothelial intracellular signaling. STAT3 is a latent cytoplasmic transcription factor involved in endothelial cell differentiation, survival, and angiogenesis. We aimed to test if preeclampsia and preeclampsia-related placental factors could alter serum-induced STAT3(Y705) activation in endothelial cells. Furthermore, if altered serum-induced endothelial STAT3 (Y705) activation is related to post-preeclamptic CVD risk.

STUDY DESIGN

HUVECs were used as a model of maternal endothelium. Experiments entailed addition of 20% human pregnancy serum as well as addition of recombinant PlGF, sFLT1 and VEGF-A_165a to the cells.

MAIN OUTCOME MEASURES

Levels of pSTAT3(Y705) related to STAT3 levels were evaluated by immunoblotting analysis.

RESULTS

Our results show that preeclamptic serum induces significantly lower STAT3(Y705) phosphorylation compared with uncomplicated pregnancy serum (P = 0.0089) in endothelial cells. Furthermore, STAT3(Y705) phosphorylation was not changed upon addition of PlGF, sFLT1, or VEGF-A_165a together with pregnancy sera compared with sera alone. Finally, sera from women with previous preeclampsia and current hypertension and carotid atherosclerotic plaques show significantly lower STAT3(Y705) phosphorylation capabilities compared with healthy women with previous uncomplicated pregnancies 8-18 years after deliveries (P = 0.029).

CONCLUSIONS

Reduction in serum-induced endothelial STAT3(Y705) activation may play an important role in the preeclampsia-associated endothelial dysfunction. Additionally, reduced endothelial STAT3(Y705) phosphorylation may contribute to increased post-preeclamptic CVD risk 8-18 years after delivery.

Placental growth factor and Fms related tyrosine kinase-1 are hypomethylated in preeclampsia placentae

Aim: This study aims to examine the DNA methylation (DNAm) and expression patterns of genes associated with placental angiogenesis in preeclampsia. Materials & methods: DNAm and expression were examined in normotensive (n = 100) and preeclampsia (n = 100) women using pyrosequencing and quantitative real-time PCR respectively. Results: Hypomethylation at several CpGs was observed in PlGF and FLT-1 in women with preeclampsia compared to normotensive controls. PlGF expression was lower in women with preeclampsia while FLT-1 expression was comparable. DNAm at various CpGs was negatively correlated with expression in both the genes and were associated with maternal blood pressure and birth outcomes. Conclusion: DNAm and expression of angiogenic factors in placentae are differentially regulated in preeclampsia and influence birth outcomes.

The prognostic role of serum uric acid levels in preeclampsia: A meta-analysis

This meta-analysis aims to compare serum uric acid levels among preeclamptic and healthy pregnant women across the various trimesters and provide a summary of the effect size of this biomarker in predicting adverse pregnancy outcomes. MEDLINE, Scopus, CENTRAL, Clinicaltrials.gov, and Google Scholar databases were systematically searched from inception. Observational studies were held eligible if they reported serum uric acid among preeclamptic and healthy pregnant women. Meta-analysis was conducted regarding uric acid concentration, diagnostic accuracy, and association with perinatal outcomes. The credibility of evidence was appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. The analysis included 196 studies, comprising 39 540 women. Preeclampsia was associated with significantly elevated uric acid levels during the 1st (mean difference [MD]: 0.21 mg/dL, 95% confidence intervals [CI]: 0.06-0.35) trimester, 2nd (MD: 1.41 mg/dL, 95% CI: 0.78-2.05) trimester, and 3rd (MD: 2.26 mg/dL, 95% CI: 2.12-2.40) trimester. Higher uric acid was estimated for severe preeclampsia, eclampsia, and hemolysis, elevated liver enzymes, low platelet syndrome. The sensitivity for adverse perinatal outcome prediction ranged from 67.3% to 82.7% and the specificity from 47.7% to 70.7%. In conclusion, it is suggested that serum uric acid levels are increased in preeclampsia and can be used to predict disease severity and pregnancy complications. Future prospective studies should verify these outcomes, assess the optimal cutoffs, and incorporate uric acid to combined predicting models.

The association between preeclampsia and the risk of metabolic syndrome after delivery: a meta-analysis

OBJECTIVE

We performed a systematic review and meta-analysis to summarize the epidemiologic evidence of the association between preeclampsia and increased risk of metabolic syndrome after delivery.

METHODS

A comprehensive literature search of numerous electronic databases including PubMed, Scopus, and Web of Sciences was performed until 1 July 2019. The pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated as random effect estimates of association among studies. Begg's and Egger's linear regression tests were employed to investigate publication bias.

RESULTS

The pooled estimates of crude and adjusted ORs showed a significant association between preeclampsia and the risk of metabolic syndrome ((crude OR = 2.93, 95% CI = 1.92-4.47) and (adjusted OR = 1.62, 95% CI = 1.25-2.08)), respectively.

CONCLUSIONS

The results of this meta-analysis provide evidence for relation between preeclampsia and increase in risk of metabolic syndrome. However, more epidemiological and clinical studies are needed to explore the mechanism of preeclampsia on increased risk of metabolic syndrome.