Early-Pregnancy Circulating Antioxidant Capacity and Hemodynamic Adaptation in Recurrent Placental Syndrome: An Exploratory Study

Prediction of severe preeclampsia and intrauterine growth restriction based on serum placental exosome miR-520a-5p levels during the first-trimester

BACKGROUND

To assess the predictive capabilities of serum exosomal levels of micro-RNA-520a-5p (miR-520a-5p) concerning the occurrence of severe preeclampsia (sPE) and fetal growth restriction (FGR) during the first trimester of pregnancy.

METHODS

During the period spanning from October 2020 to October 2021, serum samples were procured from the first trimester and subsequently preserved by freezing at -80 ℃. These samples were obtained from 105 pregnant women in a nested case-control study. This cohort consisted of individuals who later developed sPE (sPE group, n = 35) and FGR (FGR group, n = 35) during the third trimester. Additionally, 35 women with normal blood pressure were denoted as normal pregnancy group. Serum samples from the first trimester were retrieved from all groups for further analysis after thawing. Exosomes were extracted from the serum samples collected during the first trimester and examined using transmission electron microscopy, western blot, and nanoparticle tracking analysis. Additionally, the determination of their placental origin was also established during the course of the study. Exosome miR-520a-5p levels were measured using real-time quantitative polymerase chain reaction assays, primarily involving quantitative reverse transcription polymerase chain reactions. Fetal placental tissues from the 3 groups were collected shortly after birth, and miR-520a-5p expression was measured using real-time quantitative polymerase chain reaction. Serum placental exosomes and fetal placental tissues were compared for miR-520a-5p levels. Placental trophoblasts were identified as the source of serum exosomes in all 3 groups.

RESULTS

It was found that serum placental exosomes exhibited lower levels of miR-520a-5p in both the sPE and FGR groups when compared to the normal pregnancy group. This finding was consistent with observations made in postpartum placental tissues. The predictive accuracy for sPE using miR-520a-5p levels in serum placental exosomes during the first trimester was notably higher (area under the receiver operating characteristic curve = 0.806, P <.05) compared to the prediction of FGR (area under the receiver operating characteristic curve = 0.628, P <.05).

CONCLUSION

Placenta-derived exosomes can be extracted from maternal serum during the first trimester of pregnancy and miR-520a-5p detected from the exosomes. The downregulation of miR-520a-5p serves as a more predictive indicator for the subsequent development of sPE compared to predicting FGR.

NLRP3 inflammasome in peripheral blood monocytes as a risk factor for early -onset preeclampsia

INTRODUCTION

As a leading cause of pregnancy and fetal mortality, pre-eclampsia impacts about 5-8% of pregnancies globally. To date, few studies have focused on the role played by (NOD)-like receptors protein 3 (NLRP3) in peripheral blood in early-onset pre-eclampsia (PE). In this study, we investigated whether NLRP3 expression in monocytes before 20 weeks of gestation was associated with an increased risk of early-onset PE.

METHODOLOGY

During the study period from 2019 to 2021, women with singleton pregnancies were enrolled in this prospective study at the General Hospital of Northern Theater Command. A generalized additive model (GAM) and logistic regression models were applied to determine any association between NLRP3 and the risk of early-onset PE.

RESULTS

In total, 571 and 48 subjects were included in the control and pre-eclampsia groups, respectively. The GAM and logistic regression models showed that NLRP3 was a significant factor for PE occurrence. The area under the curve, accuracy, specificity, sensitivity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.86, 0.82, 0.95, 0.72, 15.17, 0.29, and 52.0, respectively.

CONCLUSION

The monitoring for NLRP3 in peripheral blood may be a potential, prospectively identifying risk factor for preeclampsia.

Oxidative stress-A key determinant of complications and negative outcome in hepatitis E virus infected pregnancies: A comprehensive account involving cases from northeast India

Regulated oxidative stress (OS) is important during pregnancy. Sporadic studies suggest the significance of deregulated OS in hepatitis E virus (HEV) infected pregnancy, but with limited reactive oxygen species (ROS) or antioxidant markers. The present novel study, therefore, aimed to evaluate the significance of ROS-antioxidant imbalance and resulting altered OS in HEV infected pregnancy complications like preterm delivery (PTD) and outcome. Difference in serum levels of ROS and antioxidant panel of markers were evaluated by ELISA for HEV immunoglobulin M RNA positive genotype 1 cases (including acute [acute viral hepatitis, AVH] and fulminant [fulminant hepatic failure, FHF] cases) and healthy term delivery subjects, and analyzed statistically. Direct ROS marker H₂ O₂ levels and indirect OS marker for DNA damage 8-hydroxy-2'-deoxyguanosine was significantly increased in HEV-cases compared to controls, and was associated and prognostic factor for PTD and fetal death in HEV cases. A comparatively lower total serum antioxidant capacity was observed in the FHF cases compared to the control subjects and the AVH cases. Glutathione (GSH) levels and superoxide dismutase (SOD) activity were significantly associated with PTD in the FHF sub-cohorts (p = 0.017) and AVH sub-cohorts (p < 0.001), respectively, and was associated with poor prognosis in HEV cases. The serum H₂ O₂ levels were found to be negatively correlated with SOD activity (p = 0.016) and GSH levels (p = 0.001) in the HEV-AVH cases; and positively correlated with the viral load in HEV cases (p = 0.023). The ROS-antioxidant imbalance resulting OS plays a detrimental associative role in HEV infected pregnancy complications like PTD and adverse pregnancy outcomes; and holds therapeutic significance.

Maternal urinary fluoride during pregnancy and birth weight and length: Results from ELEMENT cohort study

Epidemiological studies assessing prenatal fluoride exposure and anthropometry at birth are scarce, inconsistent and with methodological limitations. The aim of this study was to evaluate associations between maternal urinary fluoride (MUF) at each trimester of pregnancy and birth weight and length in 536 mother-child pairs in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort study. MUF (mg/L) was measured using microdiffusion/fluoride-specific electrode from at least one trimester of pregnancy. Non-linear associations were assessed through segmented regression models (MUF and birth weight Z-score) and we used linear regression models for MUF and birth length Z-score. Models were adjusted for potential confounders including urinary creatinine concentrations as a covariate. Non-creatinine adjusted MUF levels at each trimester of pregnancy were 0.81, 0.86, and 0.82 mg/L, mean concentrations for first, second and third trimester, respectively. For birth weight, we identified a MUF breakpoint at 0.99, 0.68 and 0.58 mg/L, for first, second and third trimester of pregnancy, respectively. In the first trimester, an increase of 1 mg/L in MUF concentrations ≥0.99 mg/L was associated with an increase in weight Z-score at birth (β = 0.79; 95% CI: 0.10, 1.48; p = 0.02). Second trimester MUF (≥0.68 mg/L) was marginally associated with birth weight decrease (β = -0.25; 95% CI: -0.55, 0.04; p = 0.09) and third trimester MUF (≥0.58 mg/L) was significantly associated with birth weight decrease (β = -0.33; 95% CI: -0.63, -0.03; p = 0.03). We observed a linear and significant association between MUF and Z-score of length at birth only for the first trimester of pregnancy (β = 0.55; 95% CI: 0.07, 1.04; p < 0.02). Prenatal fluoride exposure was associated with birthweight z-score with different susceptibility windows. Our findings reinforce the hypothesis that maternal fluoride exposure may affect birth anthropometry.

Ultra-Processed Food Consumption during Pregnancy and Its Association with Maternal Oxidative Stress Markers

Ultra-processed food (UPF) consumption during gestation may lead to increased oxidative stress (OS) and could affect pregnancy outcomes. This study aims to evaluate the association of UPF consumption during pregnancy with circulating levels of OS markers. Diet was assessed (average of three assessments) in 119 pregnant women enrolled in the OBESO perinatal cohort (Mexico), obtaining quantitative data and the percentage of energy that UPFs (NOVA) contributed to the total diet. Sociodemographic, clinical (pregestational body-mass index and gestational weight gain) and lifestyle data were collected. Maternal circulating levels of OS markers (malondialdehyde (MDA), protein carbonylation (PC), and total antioxidant capacity (TAC)) were determined at the third trimester of pregnancy. Adjusted linear regression models were performed to analyze the association between UPFs and OS markers. UPFs represented 27.99% of the total energy intake. Women with a lower UPF consumption (<75 percentile°) presented a higher intake of fiber, ω-3, ω-6, and a lower ω-6/3 ratio. Linear regression models showed that UPFs were inversely associated with TAC and MDA. Fiber intake was associated with PC. UPF intake during pregnancy may result in an increase in oxidative stress. When providing nutrition care, limiting or avoiding UPFs may be an intervention strategy that could promote a better antioxidant capacity in the body.

Assessment of the Systemic Oxidative Stress in Preeclampsia

Preeclampsia (PE) is a major complication of pregnancy with both mother and fetal adverse outcomes. Pregnancy is a state of increased oxidative stress that has been reported to be exacerbated when complicated with preeclampsia. However, conflicting data are available in literature regarding the systemic oxidative stress in PE pregnancies. The present pilot study was purported to assess systemic oxidative stress in preeclamptic vs healthy pregnancies. To this aim plasma derived compounds of reactive oxygen metabolites (d-ROMs) and the biological antioxidant potential (BAP) were determined in mild and severe preeclamptic pregnancies using the Diacron equipment. Both healthy and preeclamptic pregnancies showed high levels of systemic oxidative stress. Paradoxically, significantly higher values of d-ROMs were found in healthy pregnancies as compared to the PE ones. At variance, in preeclamptic pregnancies, a major increase in the plasma antioxidant capacity occurred. In this pilot study, we report an increase in the systemic antioxidant capacity in preeclamptic pregnancies.

Evaluation of Fetal Renal Artery Doppler Indices in Pregnancies Complicated with Preeclampsia

OBJECTIVE

Preeclampsia, characterized by endothelial dysfunction, is associated with maternal and fetal Doppler alterations. This study aimed to evaluate fetal renal artery Doppler indices in pregnancies complicated with preeclampsia and compare them with normotensive pregnancies.

DESIGN

This cross-sectional study enrolled 46 pregnancies complicated with preeclampsia between weeks 24 and 37 of gestation as the study group and 48 normotensive pregnancies as the control group.

MATERIALS AND METHODS

The abdominal aorta, its bifurcation, and the renal arteries were visualized in the coronal view of the fetal abdomen using color Doppler. Renal artery Doppler indices were measured after arising from the abdominal aorta. The angle of insonation was ≤30° from the direction of blood flow, and the sample volume was 2 mm. Fetal renal artery pulsatility index, resistance index, systolic/diastolic ratio, and peak systolic velocity (PSV) were measured. All Doppler measurements were performed in the absence of fetal movements. Moreover, demographic characteristics and the perinatal outcome data of patients were recorded.

RESULTS

The values of fetal renal artery pulsatility and resistance indices were found to be significantly lower in the study group than those in the control group (p < 0.001 and p = 0.013, respectively). The fetal renal artery systolic/diastolic ratio and PSV values were also significantly lower in the study group compared with those in the control group (p = 0.007 and p < 0.001, respectively). Renal artery pulsatility and resistance indices were negatively correlated with mean arterial pressure (r = -0.381, p < 0.001 and r = -0.267, p = 0.009, respectively). The renal artery systolic/diastolic ratio was also significantly negatively correlated with the mean arterial pressure (r = -0.257, p = 0.013).

LIMITATIONS

The main limitations of this study are its cross-sectional design and the small number of participants. Another limitation of the study is that preeclamptic pregnancies complicated with fetal growth restriction were not included.

CONCLUSION

The observed decrease in fetal renal artery Doppler impedance may be caused by the unique response of the fetal renal artery to the factors involved in the etiopathogenesis of preeclampsia than other fetal peripheral vessels. These changes in fetal renal artery indices in pregnancies complicated with preeclampsia could be taken into account in the assessment of fetal health.

Soluble Endoglin and Uterine Artery Flow Doppler Ultrasonography as Markers of Progression to Preeclampsia in Women with Gestational Hypertension

INTRODUCTION

Gestational hypertension (GH) pregnancies are at a high risk of developing adverse outcomes, including progression to preeclampsia. Prediction of GH-related adverse outcomes is challenging because there are no available clinical tests that may predict their occurrence.

OBJECTIVE

The aim of the study was to determine the clinical usefulness of the soluble endoglin (sEng) and parameters of uterine artery flow (UtAF) measured by Doppler ultrasonography as markers of progression to preeclampsia in women with GH.

SETTING

Mexico City, Mexico.

MATERIAL AND METHODS

We included 77 singleton pregnant women with GH in a nested case-control study. Cases were women who progressed to preeclampsia (n = 36), and controls were those who did not (n = 41). Serum sEng and UtAF measurements were performed at enrollment. The main outcomes measured were progression to preeclampsia and occurrence of preterm delivery (PD) <37 and <34 weeks of gestation, small for gestational age infant (SGA), and fetal growth restriction (FGR).

RESULTS

Women with sEng values in the highest tertile had higher risk of progression to preeclampsia, preterm delivery <34 weeks of gestation, and fetal growth restriction, odds ratios (ORs) ≥3.7. Patients with abnormal UtAF Dopp-ler-pulsatility index had higher risk of progression to preeclampsia, preterm delivery <34 weeks of gestation, small for gestational age infant, and fetal growth restriction (ORs ≥3.3). The presence of notch was associated with higher risk of progression to preeclampsia, preterm delivery <37 and <34 weeks of gestation, SGA infant, and fetal growth restriction (ORs ≥2.9). However, logistic regression analysis revealed that only serum sEng was a significant and independent risk factor for progression of GH to preeclampsia, preterm delivery <34 weeks of gestation, and fetal growth restriction (ORs ≥3.1).

CONCLUSIONS

In GH pregnancies, UtAF Doppler ultrasonography is associated with increased risk of adverse outcomes and progression to preeclampsia. However, serum sEng concentration appears to be a better predictor to assess the risk of adverse maternal and perinatal outcomes and progression to preeclampsia.

Association of Elevated Cord Blood Oxidative Stress Biomarkers with Neonatal Outcomes in Mothers with Pre-Eclampsia: A Case-Control Study

OBJECTIVES

The objective of this study was to determine the relationship between the levels of stress biomarkers in cord blood and pre-eclampsia (PE) in a hospital-based population of pregnant patients and evaluate the effects on pregnancy outcomes.

DESIGN

This was an observational, case-control study. Participants/Materials, Setting, Methods: This case-control study included 282 patients with severe PE and 534 women with normal pregnancy. The umbilical cord was collected at delivery and tested for malonaldehyde (MDA), reactive oxygen species (ROS), superoxide dismutase, and homocysteine (Hcy) analysis. We performed a univariate general linear regression model analysis to control potential confounders and determined the underlying influencing factors for high MDA and ROS. A receiver operating characteristic curve analysis was conducted to determine the cutoff values for identifying severe PE. Further, the severe PE group was divided into the low- or high-MDA and low- or high-ROS subgroups according to the cutoff values. Finally, we created logistic regression models to estimate the adjusted odds ratio for each perinatal outcome in the high-MDA and high-ROS subgroup.

RESULTS

The levels of MDA and ROS levels were higher in women with severe PE than in normotensive pregnant patients. However, when adjusted for cord blood Hcy levels, the difference was insignificant. Additionally, both MDA (r = 0.359, p < 0.001) and ROS (r = 0.473, p < 0.001) were positively correlated with the cord blood Hcy level. The areas under the curve of MDA and ROS levels were 0.65 (95% confidence interval [CI]: 0.60-0.69) and 0.88 (95% CI: 0.86-0.90), respectively. Higher MDA and ROS levels were associated with increased risks of a low Apgar score, admission to the NICU, and assisted ventilation for the newborn.

LIMITATIONS

The study design led to the exclusion of several participants.

CONCLUSIONS

Increased levels of oxidative stress markers in the cord blood might be significantly associated with negative effects on newborns. High levels of Hcy in the cord blood might be associated with elevated MDA and ROS concentrations in women with severe PE.

C-Reactive Protein for Prediction or Early Detection of Pre-Eclampsia: A Systematic Review

OBJECTIVE

Pre-eclampsia (PE) is a serious disease of pregnancy and one of the major causes of morbidity and mortality for both the mother and baby. This systematic review aims to detect the role of high-sensitivity C-reactive protein (CRP) in the detection of PE.

METHODS

Thirty-four articles published between 2001 and 2019 were included in this review. The articles were extracted from OVID Medline and Embase. The study designs of these articles are randomized controlled, cohort, case-control, and cross-sectional studies evaluating CRP as a marker to predict or early diagnose PE. The quality assessment of these articles is made by the modified Quality Assessment of Diagnostic Accuracy Studies 2 tool. Meta-analysis was not done because of clinical and statistical heterogeneity.

RESULTS

A positive association between CRP levels and the development of PE was confirmed in 18 studies. This positive effect was addressed in patients with normal BMI (<25 kg/m2) in 3 studies and in overweight patients in 2 studies. One study addressed this positive association in patients with a BMI ranging between 28 and 31 kg/m2. Three studies determined a cutoff level of CRP above which a significant risk of PE development should be suspected. These levels ranged between 7 and 15 mg/L.

CONCLUSION

CRP is a promising cost-effective biomarker that may be used in the prediction of PE. A CRP level higher than 15 mg/L may suggest initiation of low-dose aspirin in low-risk pregnancies.