Preeclampsia pathophysiology and adverse outcomes during pregnancy and postpartum

Immunological mechanisms in preeclampsia: A narrative review

Maternal immunologic mechanisms for tolerance are essential for a successful pregnancy because they prevent maladaptive immune responses to the placenta and semi-allogeneic fetus and promote fetal growth. Preeclampsia is a major global cause of fetal mortality and morbidity. It is characterized by new-onset hypertension and proteinuria that occurs at twenty weeks of pregnancy or later. Preeclampsia is defined by a rise in cytokines that are pro-inflammatory and antiangiogenic components in the fetoplacental unit and the vascular endothelium of pregnant women, as well as an excessive and increasing stimulation of the immune system. Crucially, inflammation can result in low birth weight and inadequate placental perfusion in neonates. Preeclampsia, which is ultimately connected to inflammatory responses, can be impacted by several immunological mechanisms. Our goal in this work was to compile the most recent research on the pathoimmunology of preeclampsia, including studies on angiogenic variables and, in particular, immunological components.

Preventing maternal morbidity and mortality from preeclampsia and eclampsia particularly in low- and middle-income countries

Preeclampsia (PE) is a complex heterogeneous disorder with overlapping clinical phenotypes that complicate diagnosis and management. Although several pathophysiological mechanisms have been proposed, placental dysfunction due to inadequate remodelling of uterine spiral arteries leading to mal-perfusion and syncytiotrophoblast stress is recognized as the unifying characteristic of early-onset PE. Placental overgrowth and or premature senescence are probably the causes of late-onset PE. The frequency of PE has increased over the last few decades due to population-wide increases in risk factors viz. obesity, diabetes, multifetal pregnancies and pregnancies at an advanced maternal age. Whilst multimodal tools with components comprising risk factors, biomarkers and sonography are used for predicting PE, aspirin is most effective in preventing early-onset PE. The incidence and clinical consequences of PE and eclampsia are influenced by socioeconomic and cultural factors, therefore management strategies should involve multi-sector partnerships to mitigate the adverse outcomes.

The relationship between Toll-like receptor-4 genes and preeclampsia outcomes

PURPOSE

The study aimed to analyse the relationship of the rs4986790 locus of the TLR4 gene with the overall risk of preeclampsia, including both its early and late forms.

METHODS

The study used standard genetic analysis methods such as DNA extraction, PCR amplification, and genotyping of the rs4986790 locus of the TLR4 gene to assess the association with the development of preeclampsia and peripartal stroke in 207 pregnant women from the southern regions of Kazakhstan from 2016 to 2022, of whom 103 had peripartal stroke on the background of preeclampsia (the main group) and 104 preeclampsia (comparative group).

RESULTS

The results of the study demonstrate that the AG and AG + GG genotypes at the rs4986790 locus of the TLR4 gene are significantly associated with an increased risk of developing an early form of preeclampsia. This opens up a new perspective in the identification of genetic markers that can serve as indicators of a tendency to develop preeclampsia in earlier periods of pregnancy.

CONCLUSION

It was noted that the rs4986790 locus did not show a statistically significant association with the risk of late preeclampsia. An important aspect of the study revealed the relationship of genotypes with the development of peripartal stroke on the background of preeclampsia. This study offers practical insights for creating targeted genetic screening and personalised treatments for preeclampsia, aiming to improve patient outcomes. To fully understand the molecular mechanisms underlying the identified association, additional research is required to identify deeper molecular pathways and relationships, and to develop new strategies for the prevention and treatment of preeclampsia.

Association of Blood Manganese and Preeclampsia: A Systematic Review and Meta-analysis

A systematic review and meta-analysis was performed to comprehensively evaluate the association between manganese (Mn) level and preeclampsia (PE) during pregnancy. Relevant observational studies were retrieved by searching Medline, Web of Science, Embase, and Cochrane Library from database inception to May 25, 2023. Pooling results was performed using a random-effects model incorporating heterogeneity. This meta-analysis incorporated 18 observational studies, which included 1113 women with PE and 5480 normotensive pregnant women. Pooled results showed that compared to normotensive control, women with PE had significantly lower blood Mn concentration (standardized mean difference: -0.36, 95% confidence interval: -0.50 to -0.22, p < 0.001; I2 = 67%). Subgroup analysis showed that the results were not significantly affected by study country (African, Asian, or Western), timing of blood sampling (before, at, or after the diagnosis of PE), mean blood Mn level of controls, or numbers of confounding factors adjusted (p for subgroup analysis all > 0.05), while methods for measuring blood Mn levels might affect the results (p for subgroup difference < 0.001). Finally, pooled results of three studies showed that a high level of blood Mn was related to a low risk of PE with blood Mn analyzed in continuous (risk ratio [RR]: 0.71, 95% CI: 0.59 to 0.85, p < 0.001; I2 = 0%) and categorized variables (RR: 0.50, 95% CI: 0.30 to 0.82, p = 0.006; I2 = 32%). In conclusion, a low blood level of Mn may be associated with PE in pregnant women.

Biomarker role of maternal soluble human leukocyte antigen G in pre-eclampsia: A meta-analysis

INTRODUCTION

Human leukocyte antigen-G (HLA-G) is a non-classical class I HLA molecule shown to regulate the immunomodulation of maternal immune cells to prevent fetal tissue destruction. Low levels of freely circulating maternal soluble HLA-G (sHLA-G) have been observed in pre-eclampsia, however, no pooled evidence exists. This meta-analysis aimed to generate pooled findings on the association of sHLA-G levels with pre-eclampsia and is the first study to perform a trimester-wise comparison of the levels of sHLA-G in preeclamptic cases and normal pregnant controls.

METHODS

The databases PubMed, Emba, Web of Science, and Google Scholar through May 31, 2023. Preeclamptic women were defined as cases and normal pregnancies as controls. Data on the level of sHLA-G in cases and controls was extracted and subjected to a meta-analysis using a random-effects model. The pooled effect was expressed in terms of standardized mean difference (SMD). Sensitivity analysis was performed to investigate the effect of the exclusion of each study on the pooled results. Publication bias was assessed statistically.

RESULTS

Nine studies with altogether 567 PE cases and 1132 normal pregnancy controls were included in the meta-analysis. The first and third trimester levels of sHLA-G in PE cases were significantly lower than that of normal pregnant controls: (SMD: -0.84 [-1.29; -0.38]; p = .003; I2 = 54%) and (SMD: -0.39 [-0.71; -0.06]; p = .02; I2 = 79%) respectively. Sensitivity analysis revealed significant fluctuations in the pooled findings when few studies were excluded, raising questions on the consistency of results among studies.

CONCLUSION

Although we found that first and third-trimester sHLA-G levels in pre-eclampsia are significantly lower, taking into consideration the inconsistent results from the sensitivity analysis, our findings advocate the demand for more studies with larger sample sizes to generate solid ground pooled evidence on the predictive role of sHLA-G in pre-eclampsia.

Maternal outcomes of pre-eclampsia with severe features and its determinants at Abebech Gobena Mothers and Childrens Health and Saint Peter's Specialized Hospital, Addis Ababa, Ethiopia: a cross-sectional study

OBJECTIVE

The main objective of this study was to determine the prevalence and factors associated with unfavourable maternal outcomes among pregnant women with pre-eclampsia with severity features (PEWSF) at Abebech Gobena Maternal and Children's Health and St. Peter's Hospital, Addis Ababa, Ethiopia, 2023.

DESIGN

A hospital-based cross-sectional study was conducted from 1 January 2023 to July 2023. The data was collected using a structured and pre-tested questionnaire through face-to-face interviews and a review clinical chart. Data was entered using EpiData V.4.6 and analysed using SPSS V.26.0 statistical software. Binary logistic regression analysis was run to identify predictors of maternal outcome.

SETTING

Two hospitals in Addis Ababa, Ethiopia.

PARTICIPANTS

348 pregnant women with PEWSF were included.

OUTCOME MEASURES

Unfavourable maternal outcome was defined as mothers with PEWSF that develop at least one complication, that is, eclampsia, abruption placenta, Haemolysis, Elevated Liver Enzymes and Low Platelet Count (HELLP) syndrome, acute renal failure, disseminated intravascular coagulation, cardiac failure, stroke, postpartum haemorrhage, pulmonary oedema and death.

RESULTS

The overall prevalence of unfavourable maternal outcomes was 33.9% (N=118) (95% CI=28.7 to 38.8). Abruptio placenta (17.2%), HELLP syndrome (15.5%) and postpartum haemorrhage (13.8%) were common complications that occurred among mothers with PEWSF. Age above 35 years (adjusted OR (AOR) (95% CI)=2.70 (1.31 to 5.59)), rural residence (AOR (95% CI)=1.94 (1.07 to 3.53)), unemployment (AOR (95% CI)=0.35 (0.20 to 0.62)), severe blood pressure on admission (AOR (95% CI)=2.32 (1.03 to 5.19)) and complain of severe headache (AOR (95% CI)=1.91 (1.16 to 3.16)) were significant associates of unfavourable maternal outcomes.

CONCLUSIONS

The prevalence of unfavourable maternal outcomes was high compared with other studies in Ethiopia. Maternal age, residence, occupation, blood pressure on admission and severe headache have shown a statistically significant association with unfavourable maternal outcomes. Socioeconomic development and early identification of severe signs and symptoms of pre-eclampsia are needed to reduce unfavourable outcomes.

Midwives' experiences of providing pre-eclampsia care in a low- and middle-income country - A qualitative study

PROBLEM

Like other low- and middle-income countries, Ghana has high maternal mortality stemming from pre-eclampsia. Ghanaian midwives are frontline service providers of emergency care in obstetric complications and have the greatest potential to maximise pre-eclampsia outcomes. Little is known about the potential barriers and challenges to midwives' capacity to provide quality care in pre-eclampsia in Ghana. Therefore, we aimed to explore and gain insights into midwives' experiences of pre-eclampsia care including their knowledge, skills, and psychological aspects such as midwives' resilience.

BACKGROUND

There is a rising global incidence of pre-eclampsia. Quality midwifery care in inter-professional collaborative practice is crucial to reducing pre-eclampsia-related morbidity and mortality.

METHODS

A qualitative descriptive exploratory study. In-depth semi-structured interviews (n = 35) were performed in 2021 and analysed by thematic analysis.

FINDINGS

There were three main themes. 1) Competence and Confidence in care; midwives provided timely and appropriate care based on sound knowledge and skills; they explained how pre-eclampsia care was organised within a multidisciplinary context and described collaborative working amongst midwives for mutual learning and support. 2) Emotional concerns and empathy; midwives' described fulfillment in achieving positive pre-eclampsia outcomes. In contrast, maternal loss was distressing and traumatic. 3) Call for improved care resources for pre-eclampsia; midwives recommended expansion of continuing professional development opportunities, appropriate infrastructure, resources, tailored public education, and a review of pre-service education to support their participation in pre-eclampsia care.

CONCLUSION

To improve the quality of care in pre-eclampsia, midwives should be capacitated, systems should promptly address barriers, and prioritise midwives' emotional well-being.

Assessing cardiovascular disease risk in women with a history of hypertensive disorders of pregnancy: A guidance paper for studies using administrative data

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are a major cause of maternal morbidity and mortality, and their association with increased cardiovascular disease (CVD) risk represents a major public health concern. However, assessing CVD risk in women with a history of these conditions presents unique challenges, especially when studies are carried out using routinely collected data.

OBJECTIVES

To summarise and describe key challenges related to the design and conduct of administrative studies assessing CVD risk in women with a history of HDP and provide concrete recommendations for addressing them in future research.

METHODS

This is a methodological guidance paper.

RESULTS

Several conceptual and methodological factors related to the data-generating mechanism and study conceptualisation, design/data management and analysis, as well as the interpretation and reporting of study findings should be considered and addressed when designing and carrying out administrative studies on this topic. Researchers should develop an a priori conceptual framework within which the research question is articulated, important study variables are identified and their interrelationships are carefully considered.

CONCLUSIONS

To advance our understanding of CVD risk in women with a history of HDP, future studies should carefully consider and address the conceptual and methodological considerations outlined in this guidance paper. In highlighting these challenges, and providing specific recommendations for how to address them, our goal is to improve the quality of research carried out on this topic.

Evaluating mean platelet volume and platelet distribution width as predictors of early-onset pre-eclampsia: a prospective cohort study

BACKGROUND

Platelets are pivotal players in the pathophysiology of pre-eclampsia, with observed lower counts in affected individuals compared to normotensive counterparts. Despite advancements, the elusive cause of pre-eclampsia persists, motivating intense global efforts to identify reliable predictors. The currently recommended predictors of pre-eclampsia are not readily available in many resource-limited regions like Nigeria. This cohort study explores the potential of mean platelet volume (MPV) and platelet distribution width (PDW) as predictive markers of early-onset pre-eclampsia. Both platelet indices are components of the full blood count, a widely available routine test in pregnancy.

METHODS

In this prospective cohort study, 648 healthy pregnant women attending antenatal care at Lagos State University Teaching Hospital and General Hospital Ifako-Ijaiye, Lagos, were recruited between 14-18weeks gestational age. Platelet count (PC), MPV and PDW were measured from their venous blood at recruitment. Participants were monitored until 34weeks of gestation, focusing on the occurrence of early-onset preeclampsia as the outcome of interest. Individuals with chronic medical conditions were excluded from the study. Data analysis involved t-test, Chi-Square and Mann-Whitney U tests, with statistical significance set at a confidence level of 95% and p < 0.05. Sensitivity, specificity, and predictive values were determined using receiver operating characteristics (ROC) curves.

RESULTS

The incidence of early-onset pre-eclampsia in the study was 5.9%. Women who later developed pre-eclampsia had higher median MPV and PDW at 14-18weeks (10.8 fl. and 24.8 fl.) compared to normotensive women (8.1 fl. and 13.3 fl.)(p < 0.001). The median PC was lower in pre-eclamptics (190 × 103/µl) compared to normotensives(264 × 103/µl)(p < 0.001). Using Youden's test, cut-off values identified: PC < 211.5 × 103/µl, MPV > 9.4 fl., and PDW > 21.3 fl., predicted early-onset pre-eclampsia with 96.6% sensitivity and 65.6% specificity for PC; 79.3% sensitivity and 97.7% specificity for PDW; and 82.8% sensitivity and 96.1% specificity for MPV. Cut-offs of PC < 185 × 103/µl, MPV > 10.7 fl., and PDW > 28.3 fl., predicted severe early-onset pre-eclampsia with 100.0% sensitivity and 90.9% specificity for PC, 100.0% sensitivity and 99.4% specificity for MPV, and 100.0% sensitivity and 99.8% specificity for PDW, with corresponding area under the ROC curves of 0.983, 0.996, and 0.998, respectively.

CONCLUSION

The evaluation of MPV and PDW between 14 and 18 weeks of gestation appears to be a reliable predictor of severe early-onset pre-eclampsia.

The clinical value of combining shear wave elastography, VOCAL technique, and T2* MRI of early gestation placenta to predict pre-eclampsia

OBJECTIVE

To investigate the clinical value of combining shear wave elastography (SWE) with the Volumetric Organ Computer-Aided AnaLysis (VOCAL) technique and T2* magnetic resonance imaging (MRI) to predict pre-eclampsia (PE).

METHODS

From December 2022 to March 2023, we recruited 31 pregnant women diagnosed with PE at our hospital as the observation group and 85 normal pregnant women as the control group. Differences in placental elasticity, vascularization index (VI), flow index (FI), vascularization flow index (VFI), and T2* MRI perfusion fraction (f) were compared between the two groups. Received operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value of placental elasticity, VI, FI, VFI, f, and their combination for predicting PE.

RESULTS

Placental elasticity was higher in the observation group than in the control group, while VI, FI, VFI, and f were lower in the observation group (all p < 0.05). The area under the curve (AUC) for placental elasticity, VI, FI, VFI, f, and their combination for predicting PE were 0.85, 0.77, 0.78, 0.84, 0.65, and 0.94, respectively. The sensitivity was 71%, 55%, 94%, 65%, 55%, and 81%. The specificity was 92%, 91%, 60%, 92%, 79%, and 98%. The combined prediction model had a higher AUC than the individual predictors (p < 0.05).

CONCLUSION

SWE combined with VOCAL technique and T2* MRI has high value for predicting PE and can provide reference information for clinical diagnosis.

Association between Serum 8-Iso-Prostaglandin F2α as an Oxidative Stress Marker and Immunological Markers in a Cohort of Preeclampsia Patients

BACKGROUND

We aimed to analyze the presence and clinical use of serum 8-iso-prostaglandin F2-alpha (8-iso-PGF2α) as an oxidative stress marker and some inflammatory status biomarkers (tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), IL-10, high-sensitivity C-reactive protein (hs-CRP), and pentraxin-3 (PTX3)) for patients with preeclampsia (PE).

METHODS

Sixty pregnant women, including thirty diagnosed with PE and thirty who were healthy (NP), were included in this study. For the assessment of serum levels of biomarkers, we used the Enzyme-Linked Immunosorbent Assay (ELISA) technique.

RESULTS

Our preliminary study showed that the expression level of serum 8-iso-PGF2α in the PE group was higher than in the PE after delivery (PE-AD) group (742.00 vs. 324.00 pg/mL, p < 0.0001). Groups of preeclamptic patients (PE + PE-AD) expressed significantly elevated levels for all of the assessed inflammatory mediators as compared to NP. Significant strong positive correlations with 8-iso-PGF2α levels were found for systolic blood pressure (SBP), and TNF-α (Spearman's rho = 0.622, p-value = 0.020 and rho = 0.645, p-value = 0.002, respectively). Our study demonstrates that 8-iso-PGF2α and PTX3 have the greatest diagnostic value for pregnant women with PE.

CONCLUSIONS

8-iso-PGF2α and PTX3 can be used as independent predictor factors, along with already-known cytokines, that could represent a prophylactic way to help clinicians identify or predict which pregnant women will develop PE.

Awareness of Preeclampsia and Its Associated Factors Among Women in Al Baha Region, Saudi Arabia

BACKGROUND

Preeclampsia is associated with the incidence of common fetal problems including intra-uterine growth restriction (IUGR), premature delivery oligohydramnios, placental abruption, fetal discomfort, and intrauterine fetal death. Pregnant women are not well-informed about preeclampsia, including its symptoms, risk factors, and consequences. The aim of the current study is to evaluate the awareness of preeclampsia and its associated factors among women in the Al Baha region, Saudi Arabia.

METHODOLOGY

An observational cross-sectional design was employed to assess the awareness of preeclampsia and its associated factors among women in the Al Baha region of Saudi Arabia. Data was collected from April 2023 to September 2023. A questionnaire was designed to gather information on participants' sociodemographic characteristics (such as age, educational level, and residency) and their awareness of preeclampsia, including knowledge about signs/symptoms, risk factors, and complications.

RESULTS

In the current study, we included 485 pregnant women. The majority of participants were aged 40 years or older (37.5%), followed by those aged 35-39 (20.4%). Among the participants, 70.9% confirmed that they had heard about pre-eclampsia before. The most common signs and symptoms were high blood pressure (47.4%), increased protein in urine (40.2%), continuous headache (39.2%), and vomiting/nausea (40.0%). Participants demonstrated awareness of obesity (29.7%), diabetes mellitus (35.5%), chronic hypertension (47.0%), and chronic kidney disease (31.3%) as major risk factors. Participants were aware of potential risks such as kidney disorders (34.6%), heart disorders (23.7%), and preterm delivery (50.9%). The analysis reveals that younger participants below 20 years old (3.3%) and lower educational levels (5.6%) had lower awareness of preeclampsia compared to older age groups.

CONCLUSION

The findings of this study highlight a reasonable level of preeclampsia awareness and knowledge among Saudi Arabian women residing in the Al Baha region. While the majority of participants were familiar with preeclampsia, there were significant knowledge gaps regarding the precise symptoms, risk factors, and consequences of the condition.

The Effects of Vitamin D Supplementation before 20 Weeks of Gestation on Preeclampsia: A Systematic Review

Preeclampsia is a leading cause of maternal and fetal morbidity and mortality worldwide. The role of vitamin D supplementation during early pregnancy in the prevention of preeclampsia remains unclear. Our objective was to synthesize and critically appraise the available evidence from observational and interventional studies to determine the effects of early pregnancy vitamin D supplementation on the risk of preeclampsia. A systematic review was conducted in March 2023 using PubMed, Web of Science, Cochrane, and Scopus databases, including literature published up to February 2023. In adherence to PRISMA guidelines, a structured and systematic search strategy was employed. A total of five studies were included in the review, encompassing 1474 patients. Overall, vitamin D supplementation during early pregnancy was associated with a reduced incidence of preeclampsia in all studies (ORs ranging from 0.26 to 0.31), while others showed an increased risk of preeclampsia with low vitamin D levels during the first trimester (ORs of 4.60, 1.94, and 2.52). However, other studies found no significant protective effect but good overall safety for various vitamin D dosages administered during the first trimester. Nevertheless, variations in vitamin D dosage, the timing of supplementation, and definitions of vitamin D insufficiency may have contributed to the inconsistencies in the observed outcomes. Some studies reported significant secondary outcomes, such as a reduction in blood pressure, preterm labor, and improved neonatal outcomes, such as birth weight. The evidence from this systematic review suggests that early pregnancy vitamin D supplementation may have a role in reducing the risk of preeclampsia. However, inconsistencies in the timing of supplementation, dosages, and methodological differences between studies highlight the need for further research to determine the optimal supplementation strategy and to clarify the relationship between vitamin D and preeclampsia risk.

Use of cell-free signals as biomarkers for early and easy prediction of preeclampsia

Introduction

Preeclampsia (PE) is a leading cause of maternal and perinatal morbidity worldwide. However, current methods of screening are complicated and require special skill sets. In this observational study of prospectively collected samples, we wanted to evaluate if cell-free (cf) DNA could be an efficient biomarker for identification of at-risk patients.

Methods

One hundred patients attending a private prenatal clinic in Canada were enrolled in their first trimester of pregnancy and a blood draw was carried out at 11 + 0 to 14 + 2 weeks' (timepoint A) and 17 + 6 to 25 + 5 weeks of gestation (timepoint B). CfDNA signals, namely concentration, fetal fraction, and fragment size distribution, were correlated with clinical outcomes in the test population to develop the logistic regression model.

Results

Twelve patients developed PE-four early-stage and eight late-stage PE. Significant differences were observed between PE patients and control cases for all three cfDNA signals at timepoint A, while both fetal fraction and concentration were significantly different between PE patients and control cases at timepoint B. Overall, the model had a sensitivity of up to 100% and specificity of up to 87.5% at Timepoint A.

Conclusion

This proof-of-principle study showed that use of this logistic regression model could identify patients at risk of preeclampsia in the first trimester of pregnancy.