Predictive Value of the sFlt-1:PlGF Ratio in Women with Suspected Preeclampsia

Diagnosis of preeclampsia using metabolomic biomarkers

The diagnostic criteria for preeclampsia do not accurately reflect the pathophysiological characteristics of patients with preeclampsia. Conventional biomarkers and diagnostic approaches have proven insufficient to fully comprehend the intricacies of preeclampsia. This study aimed to screen differentially abundant metabolites as candidate biomarkers for preeclampsia. A propensity score matching method was used to perform a 1:1 match between preeclampsia patients (n = 70) and healthy control individuals (n = 70). Based on univariate and multivariate statistical analysis methods, the different characteristic metabolites were screened and identified. Least absolute shrinkage and selection operator (LASSO) regression analysis was subsequently used to further screen for differentially abundant metabolites. A receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic efficacy of the metabolites. A total of 1,630 metabolites were identified and quantified in maternal serum samples. Fifty-three metabolites were significantly increased, and two were significantly decreased in preeclampsia patients. The area under the curve (AUC) of the model composed of isobutyryl-L-carnitine and acetyl-leucine was 0.878, and the sensitivity and specificity in detecting preeclampsia were 81.4% and 87.1%, respectively. There are significant differences in metabolism between preeclampsia patients and healthy pregnant women, and a range of novel biomarkers have been identified. These findings lay the foundation for the use of metabolomic biomarkers for the diagnosis of preeclampsia.

Does a sFlt-1/PlGF ratio result > 655 before 34 weeks' gestation necessitate preterm delivery within 2 days? A retrospective observational study

INTRODUCTION

Preeclampsia is associated with adverse perinatal outcomes, including fetal growth restriction (FGR) and preterm delivery. The maternal serum ratio of soluble fms-like tyrosine kinase receptor-1 (sFlt-1) to placental growth factor (PlGF) can be used to evaluate placental dysfunction in cases of preeclampsia and FGR. A need for delivery within 2 days has been recommended for sFlt-1/PlGF ratios > 655 (normal ratio < 38) measured before 34 weeks' gestation. However, few studies have assessed this recommendation in a real-world setting and there remains a need for further evidence-based guidance on the use of the ratio in delivery timing planning in this situation.

AIM

To assess the need for delivery within 2 days associated with sFlt-1/PlGF ratios > 655 before 34 weeks' gestation.

METHODS

A retrospective audit of all sFlt-1/PlGF ratio test results obtained at a single maternity hospital between September 2016 and November 2022. The primary outcome was time to delivery after recording a ratio > 655 in patients with a pregnancy between 20 + 0 and 33 + 6 weeks' gestation. Statistical analysis was performed using IBM SPSS Statistics v29.0.0.0.

RESULTS

During the study period a total of 33 patients with suspected or confirmed preeclampsia and/or FGR recorded sFlt-1/PlGF ratios > 655 before 34 + 0 weeks' gestation. Amongst cases with ratios > 655, median time to delivery was 4 days (IQR 1.0-9.0), with 14 (42.4%) delivering in ≤ 2 days, 8 (24.2%) delivering between 2 and 7 days and 11 (33.3%) delivering after 7 days. A significant inverse correlation was observed between time to delivery and gestational age at the time of ratio testing (rs = -0.484, p = 0.004).

DISCUSSION

This study provides updated recommendations on the use of the sFlt-1/PlGF ratio in predicting the risk of imminent delivery amongst those with high ratios > 655 measured before 34 weeks' gestation. Our results suggest that the risk of imminent delivery can be stratified based on ratio level and gestational age, which in combination with the results of other clinical assessments, can be used to plan delivery timing and allow for considerations of fetal lung maturing corticosteroid and neuroprotective magnesium sulfate therapies prior to delivery.

A mitochondrial regulator protein, MNRR1, is elevated in the maternal blood of women with preeclampsia

OBJECTIVE

Preeclampsia, one of the most serious obstetric complications, is a heterogenous disorder resulting from different pathologic processes. However, placental oxidative stress and an anti-angiogenic state play a crucial role. Mitochondria are a major source of cellular reactive oxygen species. Abnormalities in mitochondrial structures, proteins, and functions have been observed in the placentae of patients with preeclampsia, thus mitochondrial dysfunction has been implicated in the mechanism of the disease. Mitochondrial nuclear retrograde regulator 1 (MNRR1) is a newly characterized bi-organellar protein with pleiotropic functions. In the mitochondria, this protein regulates cytochrome c oxidase activity and reactive oxygen species production, whereas in the nucleus, it regulates the transcription of a number of genes including response to tissue hypoxia and inflammatory signals. Since MNRR1 expression changes in response to hypoxia and to an inflammatory signal, MNRR1 could be a part of mitochondrial dysfunction and involved in the pathologic process of preeclampsia. This study aimed to determine whether the plasma MNRR1 concentration of women with preeclampsia differed from that of normal pregnant women.

METHODS

This retrospective case-control study included 97 women with preeclampsia, stratified by gestational age at delivery into early (<34 weeks, n = 40) and late (≥34 weeks, n = 57) preeclampsia and by the presence or absence of placental lesions consistent with maternal vascular malperfusion (MVM), the histologic counterpart of an anti-angiogenic state. Women with an uncomplicated pregnancy at various gestational ages who delivered at term served as controls (n = 80) and were further stratified into early (n = 25) and late (n = 55) controls according to gestational age at venipuncture. Maternal plasma MNRR1 concentrations were determined by an enzyme-linked immunosorbent assay.

RESULTS

1) Women with preeclampsia at the time of diagnosis (either early or late disease) had a significantly higher median (interquartile range, IQR) plasma MNRR1 concentration than the controls [early preeclampsia: 1632 (924-2926) pg/mL vs. 630 (448-4002) pg/mL, p = .026, and late preeclampsia: 1833 (1441-5534) pg/mL vs. 910 (526-6178) pg/mL, p = .021]. Among women with early preeclampsia, those with MVM lesions in the placenta had the highest median (IQR) plasma MNRR1 concentration among the three groups [with MVM: 2066 (1070-3188) pg/mL vs. without MVM: 888 (812-1781) pg/mL, p = .03; and with MVM vs. control: 630 (448-4002) pg/mL, p = .04]. There was no significant difference in the median plasma MNRR1 concentration between women with early preeclampsia without MVM lesions and those with an uncomplicated pregnancy (p = .3). By contrast, women with late preeclampsia, regardless of MVM lesions, had a significantly higher median (IQR) plasma MNRR1 concentration than women in the control group [with MVM: 1609 (1392-3135) pg/mL vs. control: 910 (526-6178), p = .045; and without MVM: 2023 (1578-8936) pg/mL vs. control, p = .01].

CONCLUSIONS

MNRR1, a mitochondrial regulator protein, is elevated in the maternal plasma of women with preeclampsia (both early and late) at the time of diagnosis. These findings may reflect some degree of mitochondrial dysfunction, intravascular inflammation, or other unknown pathologic processes that characterize this obstetrical syndrome.

Update on Preeclampsia and Hypertensive Disorders of Pregnancy

There have been recent advances in the prevention, diagnosis, and management of hypertensive disorders of pregnancy which complicate approximately 16% of pregnancies in the United States. Initiation of low-dose aspirin by 16 weeks' gestation reduces preeclampsia in high-risk women. The Food and Drug Administration approved the use of the soluble fms-like tyrosine kinase 1/placental growth factor ratio for the short-term prediction of preeclampsia. Pregnancy outcomes are improved in women with chronic hypertension when antihypertensives are initiated at a threshold blood pressure of 140/90 mm Hg. Women with prior preeclampsia have increased cardiovascular disease risk and should receive risk reduction counseling.

Importance of the (Pro)renin Receptor in Activating the Renin-Angiotensin System During Normotensive and Preeclamptic Pregnancies

PURPOSE OF REVIEW

For a healthy pregnancy to occur, a controlled interplay between the maternal circulating renin-angiotensin-aldosterone system (RAAS), placental renin-angiotensin system (RAS) and intrarenal renin-angiotensin system (iRAS) is necessary. Functionally, both the RAAS and iRAS interact to maintain blood pressure and cardiac output, as well as fluid and electrolyte balance. The placental RAS is important for placental development while also influencing the maternal circulating RAAS and iRAS. This narrative review concentrates on the (pro)renin receptor ((P)RR) and its soluble form (s(P)RR) in the context of the hypertensive pregnancy pathology, preeclampsia.

RECENT FINDINGS

The (P)RR and the s(P)RR have become of particular interest as not only can they activate prorenin and renin, thus influencing levels of angiotensin II (Ang II), but s(P)RR has now been shown to directly interact with and stimulate the Angiotensin II type 1 receptor (AT1R). Levels of both placental (P)RR and maternal circulating s(P)RR are elevated in patients with preeclampsia. Furthermore, s(P)RR has been shown to increase blood pressure in non-pregnant and pregnant rats and mice. In preeclamptic pregnancies, which are characterised by maternal hypertension and impaired placental development and function, we propose that there is enhanced secretion of s(P)RR from the placenta into the maternal circulation. Due to its ability to both activate prorenin and act as an AT1R agonist, excess maternal circulating s(P)RR can act on both the maternal vasculature, and the kidney, leading to RAS over-activation. This results in dysregulation of the maternal circulating RAAS and overactivation of the iRAS, contributing to maternal hypertension, renal damage, and secondary changes to neurohumoral regulation of fluid and electrolyte balance, ultimately contributing to the pathophysiology of preeclampsia.

Maternal hypothyroidism and the risk of preeclampsia: a Danish national and regional study

BACKGROUND

Maternal hypothyroidism in pregnancy has been proposed to increase the risk of preeclampsia, but uncertainties persist regarding the underlying causal mechanisms. Thus, it remains unclear if an increased risk of preeclampsia in hypothyroid pregnant women is caused by the lack of thyroid hormones or by the autoimmunity per se.

METHODS

We conducted a retrospective study of two pregnancy cohorts in the Danish population. The nationwide cohort (n = 1,014,775) was register-based and included all singleton pregnancies in Denmark from 1999-2015. The regional cohort (n = 14,573) included the biochemical measurement of thyroid stimulating hormone (TSH), thyroid peroxidase antibodies (TPO-Ab), and thyroglobulin antibodies (Tg-Ab) (ADVIA Centaur XPT, Siemens Healthineers) among pregnant women in The North Denmark Region from 2011-2015 who had a blood sample drawn in early pregnancy as part of routine prenatal screening for chromosomal anomalies. The associations between diagnosed and biochemically assessed hypothyroidism and a diagnosis of preeclampsia were evaluated using logistic regression (adjusted odds ratio (aOR) with 95% confidence interval (CI)) adjusting for potential confounders, such as maternal age, diabetes, and parity.

RESULTS

In the nationwide cohort, 2.2% of pregnant women with no history of hypothyroidism (reference group (ref.)) were diagnosed with preeclampsia, whereas the prevalence was 3.0% among pregnant women with hypothyroidism (aOR 1.3 (95% CI: 1.2-1.4)) and 4.2% among women with newly diagnosed hypothyroidism in the pregnancy (aOR 1.6 (95% CI: 1.3-2.0)). In the regional cohort, 2.3% of women with early pregnancy TSH < 2.5 mIU/L (ref.) were diagnosed with preeclampsia. Among women with TSH ≥ 6 mIU/L, the prevalence was 6.2% (aOR 2.4 (95% CI: 1.1-5.3)). Considering thyroid autoimmunity, preeclampsia was diagnosed in 2.2% of women positive for TPO-Ab (> 60 U/mL) or Tg-Ab (> 33 U/mL) in early pregnancy (aOR 0.86 (95% CI: 0.6-1.2)).

CONCLUSIONS

In two large cohorts of Danish pregnant women, maternal hypothyroidism was consistently associated with a higher risk of preeclampsia. Biochemical assessment of maternal thyroid function revealed that the severity of hypothyroidism was important. Furthermore, results did not support an association between thyroid autoimmunity per se and preeclampsia.

The sFLT-1/PlGF Ratio for the Prediction of Preeclampsia-Related Adverse Fetal and Maternal Outcomes in Women with Preexisting Diabetes

To evaluate the predictive value of the sFlt-1/PlGF ratio for the prediction of preeclampsia in women with preexisting diabetes mellitus. This is a monocentric retrospective observational study conducted between January 2018 and December 2020. All singleton pregnancies with preexisting diabetes mellitus, who had a dosage of the sFlt-1/PlGF ratio between 30 and 34 + 6 weeks of gestation were included. The principal outcome was preeclampsia. The secondary outcomes were preterm preeclampsia, gestational hypertension, placental abruption, intrauterine fetal death, IUGR, small for gestational age and a composite outcome named "hypertensive disorder of pregnancy" including gestational hypertension, preeclampsia and HELLP syndrome (hemolysis, elevated liver enzymes and low platelet count). Of 63 patients, 22% presented preeclampsia. The area under the curve of sFlt-1/PlGF ratio was 0.90 (95% CI: 0.79-0.96) for the prediction of preeclampsia. The receiver operator characteristic analysis suggested that the optimal sFlt-1/PlGF cutoff to predict preeclampsia was 29, with a sensitivity of 86% (95% CI: 60.1-96.0) and a specificity of 92% (95% CI: 80.8-96.8). A cut-off of 38 provided a sensitivity of 71% (95% CI: 45.4-88.3), a specificity of 92% (95% CI: 80.8-96.8). Further analysis using multivariable methods revealed nephropathy was significantly associated with PE (p = 0.014). The use of the sFlt-1/PlGF ratio during the third trimester of pregnancy seems to be of interest as a prognostic tool to improve multidisciplinary management of patients with preexisting diabetes mellitus.

sFlt1/PlGF among patients with suspected preeclampsia when considering hypertensive status

BACKGROUND

In high-resource settings, biomarkers of angiogenic balance, such as the soluble fms-like tyrosine kinase-1 (sFlt1)/placental growth factor (PlGF) ratio, have been studied extensively to aid in evaluation of patients with suspected preeclampsia (PE), and have been incorporated into the 2021 International Society for the Study of Hypertension in Pregnancy definition of PE. The utility in under-resourced settings has not been as well characterized.

OBJECTIVE

This analysis sought to identify the role of the sFlt1/PlGF ratio in the evaluation of patients with or without hypertension who are suspected of having PE without other diagnostic information.

STUDY DESIGN

This is a secondary analysis of a prior prospective study of patients who were presented with suspected PE at ≥20+0 weeks' gestation at a single academic tertiary care center. Patients were recruited in the parent study from July 2009 to June 2012. In the original study, clinicians were masked to biomarker results, and patients were followed by chart review. In this analysis, the performance of the sFlt1/PlGF ratio (≤38, >38, or >85) was assessed alone in identifying both hypertensive and non-hypertensive patients at risk of evolving into PE with severe features (PE-SF; American College of Obstetricians and Gynecologists' definition) within two weeks of the triage visit (PE-SF2). Hypertension was defined as a blood pressure (BP)≥140/90 mmHg.

RESULTS

There were 1043 patients included in the analysis; of whom, 579 (55.5%) and 464 (44.5%) presented with or without hypertension, respectively. In triage, 332 (75.4%) of hypertensive patients presented due to BP concerns, and the remainder were evaluated due to other features (new-onset headache, proteinuria, or edema). On triage evaluation, 66.8% of all patients had a normal sFlt1/PlGF ratio ≤38, and 17.0% had an elevated ratio >85. Among hypertensive patients, a sFlt1/PlGF ratio ≤38 was a good rule-out test for PE-SF2 (negative likelihood ratio [LR-] of 0.15), and a ratio >85 was a good rule-in test (positive likelihood ratio [LR+] of 5.75). Among normotensive patients, sFlt1/PlGF was useful as a rule-in test for ratio >38 (LR+ 5.13) and >85 (LR+ 12.80). Stratified by gestational age, sFlt1/PlGF continued to be a good rule in and good rule out test at <35 weeks among those with hypertension but did not have good test performance ≥35 weeks. sFlt1/PlGF had a good test performance as a rule in test for >85 regardless of gestational age. In triage, 4.3% (30/693) of patients with sFlt1/PlGF ratio <38 had concurrent laboratory evidence of PE, compared with 15.9% (28/176) patients with ratio >85.

CONCLUSION

These findings support the potential for the use of sFlt1/PlGF and BP measurement alone in resource-limited settings where other laboratory tests or clinical expertise are unavailable for risk stratification. Performance of the biomarker varied by the presence of hypertension and gestational age.

Evaluation of diagnostic potential of maternal serum ischemia modified albumin in cases of pre-eclampsia

OBJECTIVES

The underlying causes and mechanisms of pre-eclampsia (PE), its exact etiology remains unclear and poorly understood. Hypoxia, ischemia, and oxidative stress induced by free radicals have been associated with development of PE. Ischemia-modified albumin (IMA) is a chemically modified albumin due to oxidative stress. IMA, a serum biomarker of hypoxia, ischemia, and oxidative free radicals is a potential biomarker for PE. The aim of the current proposal was to study serum IMA as a diagnostic biomarker of pre-eclampsia (PE) in pregnant females and to evaluate the correlation between serum IMA and different markers of pre-eclampsia (BP, urinary protein, LFT, KFT, serum total protein & uric acid).

METHODS

A total of 60 pregnant women aged between 21 and 35 years were recruited (30 PE cases and 30 normal pregnancy). Serum IMA was measured by spectrophotometric method developed by Bar-Or D. BP and biochemical parameters (urinary protein, LFT, KFT, serum total protein & uric acid) were also assayed and compared between two groups. Correlation analysis was done for analyzing the relationship between serum IMA and biochemical parameters.

RESULTS

The mean serum IMA was significantly higher in normotensive pregnant females (0.93 ABSU) than PE cases (0.71 ABSU). Kidney function and liver function parameters were more deranged in PE cases than in controls. Serum IMA was positively correlated with serum creatinine (r=0.322), serum uric acid (r=0.54) and urinary protein (0.376) whereas negatively correlated with total serum bilirubin (r=-0.515) and serum albumin (r=-0.380).

CONCLUSIONS

Elevated serum IMA concentrations in normotensive pregnant controls as compared to PE cases suggest that apart from ongoing ischemia and oxidative stress in placenta IMA values are influenced by many other mechanisms in pregnancy.

Hierarchical lncRNA regulatory network in early-onset severe preeclampsia

BACKGROUND

Recent studies have shown that several long non-coding RNAs (lncRNAs) in the placenta are associated with preeclampsia (PE). However, the extent to which lncRNAs may contribute to the pathological progression of PE is unclear.

RESULTS

Here, we report a hierarchical regulatory network involved in early-onset severe PE (EOSPE). We have carried out transcriptome sequencing on the placentae from patients and normal subjects to identify the differentially expressed genes (DEGs), including some lncRNAs (DElncRNAs). We then constructed a high-quality hierarchical regulatory network of lncRNAs, transcription factors (TFs), and target DEGs, containing 1851 lncRNA-TF interactions and 6901 TF-promoter interactions. The lncRNA-to-target regulatory interactions were further validated by the triplex structures between the DElncRNAs and the promoters of the target DEGs. The DElncRNAs in the regulatory network were clustered into 3 clusters, one containing DElncRNAs correlated with the blood pressure, including FLNB-AS1 with targeting 27.89% (869/3116) DEGs in EOSPE. We further demonstrated that FLNB-AS1 could bind the transcription factor JUNB to regulate a series members of the HIF-1 signaling pathway in trophoblast cells.

CONCLUSIONS

Our results suggest that the differential expression of lncRNAs may perturb the lncRNA-TF-DEG hierarchical regulatory network, leading to the dysregulation of many genes involved in EOSPE. Our study provides a new strategy and a valuable resource for studying the mechanism underlying gene dysregulation in EOSPE patients.

The potential of repeated mean arterial pressure measurements for predicting early- and late-onset pre-eclampsia in twin pregnancies: Prediction model study

OBJECTIVE

To investigate the contribution of longitudinal mean arterial pressure (MAP) measurement during the first, second, and third trimesters of twin pregnancies to the prediction of pre-eclampsia.

METHODS

A retrospective cohort study was conducted on women with twin pregnancies. Historical data between 2019 and 2021 were analyzed, including maternal characteristics and mean artery pressure measurements were obtained at 11-13, 22-24, and 28-33 weeks of gestation. The outcome measures included pre-eclampsia with delivery <34 and ≥34 weeks of gestation. Models were developed using logistic regression, and predictive performance was evaluated using the area under the curve, detection rate at a given false-positive rate of 10%, and calibration plots. Internal validation was conducted via bootstrapping.

RESULTS

A total of 943 twin pregnancies, including 36 (3.82%) women who experienced early-onset pre-eclampsia and 93 (9.86%) who developed late-onset pre-eclampsia, were included in this study. To forecast pre-eclampsia during the third trimester, the most accurate prediction for early-onset pre-eclampsia resulted from a combination of maternal factors and MAP measured during this trimester. The optimal predictive model for late-onset pre-eclampsia includes maternal factors and MAP data collected during the second and third trimesters. The areas under the curve were 0.937 (95% confidence interval [CI] 0.894-0.981) and 0.887 (95% CI 0.852-0.921), respectively. The corresponding detection rates were 83.33% (95% CI 66.53%-93.04%) for early-onset pre-eclampsia and 68.82% (95% CI 58.26%-77.80%) for late-onset pre-eclampsia.

CONCLUSION

Repeated measurements of MAP during pregnancy significantly improved the accuracy of late-onset pre-eclampsia prediction in twin pregnancies. The integration of longitudinal data into pre-eclampsia screening may be an effective and valuable strategy.

Air Pollution-Linked Epigenetic Modifications in Placental DNA: Prognostic Potential for Identifying Future Foetal Anomalies

Prenatal exposure to air pollution is a significant risk factor for the mother and the developing foetus. The accumulation of pollutants in the placenta can cause a self-cascade loop of pro-inflammatory cytokine responses and DNA double-strand breaks. Previous research has shown that airborne particulate matter can damage the epigenome and disturb mitochondrial machinery, ultimately impairing placental function. Mitochondria are essential for preserving cellular homeostasis, energy metabolism, redox equilibrium, and epigenetic reprogramming. As these organelles are subtle targets of environmental exposures, any disruption in the signaling pathways can result in epigenomic instability, which can impact gene expression and mitochondrial function. This, in turn, can lead to changes in DNA methylation, post-translational histone modifications, and aberrant expression of microRNAs in proliferating trophoblast cells. The placenta has two distinct layers, cytotrophoblasts, and syncytiotrophoblasts, each with its mitochondria, which play important roles in preeclampsia, gestational diabetes, and overall health. Foetal nucleic acids enter maternal circulation during placental development because of necrotic, apoptotic, and inflammatory mechanisms. These nucleic acids reflect normal or abnormal ongoing cellular changes during prenatal foetal development. Detecting cell-free DNA in the bloodstream can be a biomarker for predicting negative pregnancy-related outcomes and recognizing abnormalities in foetal growth. Hence, a thorough understanding of how air pollution induces epigenetic variations within the placenta could offer crucial insights into underlying mechanisms and prolonged repercussions on foetal development and susceptibility in later stages of life.

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.

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 angiogenic factor disruptions prior to clinical diagnosis of preeclampsia: insights from the REVAMP study

Preeclampsia is characterized by impaired angiogenesis and assessment of angiogenic factors can play a crucial role in the early diagnosis of preeclampsia. The current study reports the levels of angiogenic factors longitudinally from early pregnancy in women with preeclampsia and in the subtypes of preeclampsia, to identify their role in early prediction of preeclampsia. A total of 1154 women with singleton pregnancies were recruited in early pregnancy from 2 hospitals. Blood samples were collected, plasma samples were separated and stored at four time points across gestation: V1 = 11-14 weeks, V2 = 18-22 weeks, V3 = 26-28 weeks, and V4 = at delivery. The current study includes a total of 108 women developed preeclampsia (PE), and 216 matched controls. Angiogenic factors were estimated using commercially available ELISA kits. Receiver operating characteristic (ROC) curves were used to evaluate the potential diagnostic value in the prediction of PE. Lower levels of VEGF, PlGF, and higher levels of sEng and sEng/PlGF ratio (p < 0.05 for all) predate clinical diagnosis in women with preeclampsia. sEng levels and sEng/PlGF ratio showed significant correlation with odds of preeclampsia at all the timepoints. This study identifies a cut off of 33.5 for sFlt-1/PlGF and 25.9 for sEng/PlGF for prediction of early onset preeclampsia. This study reports various angiogenic factors serially across gestation in a general population to identify women at risk of developing preeclampsia and its subtypes. The study also reports a potential biomarker and a pragmatic window for estimation of angiogenic markers to identify women at risk.

The sFlt-1/PlGF-ratio and the risk of preeclampsia-related adverse outcomes in subsequent pregnancies with signs and symptoms of a preeclampsia

OBJECTIVES

This study characterizes the outcome of two subsequent pregnancies with suspected preeclampsia (PE). We investigated the diagnostic accuracy of clinical signs, Doppler examinations, and the soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF)-ratio to predict PE-related adverse outcomes (AO). The sFlt-1/PlGF-ratio of the first pregnancy was compared to the outcome of the subsequent pregnancy.

STUDY DESIGN

A total of 1928 patients at risk for preeclampsia were screened, of them 1117 were eligible for inclusion. Of these, 84 women presented with suspected PE in two subsequent pregnancies.

OUTCOME MEASURES

Diagnostic accuracy of clinical markers was assessed. Associations between the sFlt-1/PlGF-ratio in the first and the odds of an AO in the subsequent pregnancy were investigated with logistic regression.

RESULTS

The prevalence of AOs decreased from 27.4 % in the first to 17.9 % in the second pregnancy. Comparison of the accuracy of the different clinical markers for an AO showed a high specificity for an sFlt-1/PlGF-ratio at the cut-off of ≥ 85 in both pregnancies (81.3 %, 95 % CI 63.6-92.8 vs 92.6 %,95 % CI 83.7-97.6), but a lower sensitivity in the second pregnancy (92.9 %, 95 % CI 66.1-99.8 vs 33.3%, 95 % CI 11.8-61.6). An elevated sFlt-1/PlGF-ratio in the first did not increase the odds of an AO in the subsequent pregnancy.

CONCLUSIONS

The prevalence of AOs decreases in subsequent pregnancies. Our finding that the sFlt-1/PlGF-ratio of the first was not related to the outcome of the subsequent pregnancy suggests that angiogenic markers are only a within-pregnancy short-term tool to assess AOs.

Prediction of preterm birth in growth-restricted and appropriate-for-gestational-age infants using maternal PlGF and the sFlt-1/PlGF ratio-A prospective study

OBJECTIVE

To assess the utility of placental growth factor (PlGF) levels and the soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio to predict preterm birth (PTB) for infants with fetal growth restriction (FGR) and those appropriate for gestational age (AGA).

DESIGN

Prospective, observational cohort study.

SETTING

Tertiary maternity hospital in Australia.

POPULATION

There were 320 singleton pregnancies: 141 (44.1%) AGA, 83 (25.9%) early FGR (<32+0 weeks) and 109 (30.0%) late FGR (≥32+0 weeks).

METHODS

Maternal serum PlGF and sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. Low maternal PlGF levels and elevated sFlt-1/PlGF ratio were defined as <100 ng/L and >5.78 if <28 weeks and >38 if ≥28 weeks respectively. Cox proportional hazards models were used. The analysis period was defined as the time from the first measurement of PlGF and sFlt-1/PlGF ratio to the time of birth or censoring.

MAIN OUTCOME MEASURES

The primary study outcome was overall PTB. The relative risks (RR) of birth within 1, 2 and 3 weeks and for medically indicated and spontaneous PTB were also ascertained.

RESULTS

The early FGR cohort had lower median PlGF levels (54 versus 229 ng/L, p < 0.001) and higher median sFlt-1 levels (2774 ng/L versus 2096 ng/L, p < 0.001) and sFlt-1/PlGF ratio higher (35 versus 10, p < 0.001). Both PlGF <100 ng/L and elevated sFlt-1/PlGF ratio were strongly predictive for PTB as well as PTB within 1, 2 and 3 weeks of diagnosis. For both FGR and AGA groups, PlGF <100 ng/L or raised sFlt-1/PlGF ratio were strongly associated with increased risk for medically indicated PTB. The highest RR was seen in the FGR cohort when PlGF was <100 ng/L (RR 35.20, 95% CI 11.48-175.46).

CONCLUSIONS

Low maternal PlGF levels and elevated sFlt-1/PlGF ratio are potentially useful to predict PTB in both FGR and AGA pregnancies.

Significance of the sFlt-1/PlGF Ratio in Certain Cohorts - What Needs to be Considered?

The sFlt-1/PlGF ratio is an established tool in clinical practice, where it is part of a diagnostic algorithm and informs the prognosis of preeclampsia (PE). Maternal and gestational comorbidities can affect the performance of the sFlt-1/PlGF ratio and its constituent elements, and a good understanding of the potential pitfalls is required. The objective of this paper was to provide a current narrative review of the literature on the diagnostic and predictive performance of the sFlt-1/PlGF ratio in specific patient cohorts. Potential factors which can negatively affect the clinical interpretability and applicability of the sFlt-1/PlGF ratio include chronic kidney disease, twin pregnancy, and maternal obesity. Pathophysiological mechanisms related to these factors and disorders can result in different concentrations of sFlt-1 and/or PlGF in maternal blood, meaning that the use of standard cut-off values in specific cohorts can lead to errors. To what extent the cut-off values should be adapted in certain patient cohorts can only be clarified in large prospective cohort studies. This applies to the use of the ratio both for diagnosis and prognosis.

Prediction of preeclampsia using maternal circulating mRNAs in early pregnancy

PURPOSE

Preeclampsia (PE) is one of the most common and serious complications of pregnancy, and novel methods for the early prediction of PE are needed for clinical application.

METHODS

In this study, a circulating cell-free RNA (cfRNA) panel of target genes for PE prediction was designed and validated in a case-control cohort and a nested case-control cohort. The QPCR was applied to quantify the copy number of cfRNA, and the data were normalized as multiples of the median. Ratios of serum placental growth factor (PIGF) and soluble fms-like tyrosine kinase 1 (sFLT-1) were also measured, and transabdominal ultrasonography was conducted for subjects in the prospective cohort. Binary logistic regression models for PE prediction were constructed and tested.

RESULTS

Our results revealed that the women with PE showed significant alterations in serum cfRNA profiles from early pregnancy onward and before the onset of PE symptoms. Compared with PIGF/sFLT-1 measurement and ultrasonographic imaging, cfRNA test can detect PE at a very early stage of pregnancy. The predictive model exhibited the best performance at gestation week 32, with a detection rate of 100%. At 12 weeks of gestation, the model still manifested an area under curve (AUC) of 0.9144, and sensitivity of 1.0000. If combined with clinical parameters and ultrasonographic indicators, the model can achieve the highest AUC for PE prediction at early gestation.

CONCLUSION

Measurement of cfRNA can be used to effectively predict PE with high performance, providing an additional method for monitoring PE throughout the course of pregnancy.

Doppler ultrasound of umbilical and middle cerebral artery in third trimester small-for-gestational age fetuses to decide on timing of delivery for suspected fetal growth restriction: A cohort with nested RCT (DRIGITAT)

OBJECTIVE

To assess the association of the umbilicocerebral ratio (UCR) with adverse perinatal outcome in late preterm small-for-gestational age (SGA) fetuses and to investigate the effect on perinatal outcomes of immediate delivery.

DESIGN

Multicentre cohort study with nested randomised controlled trial (RCT).

SETTING

Nineteen secondary and tertiary care centres.

POPULATION

Singleton SGA pregnancies (estimated fetal weight [EFW] or fetal abdominal circumference [FAC] <10th centile) from 32 to 36+6 weeks.

METHODS

Women were classified: (1) RCT-eligible: abnormal UCR twice consecutive and EFW below the 3rd centile at/or below 35 weeks or below the 10th centile at 36 weeks; (2) abnormal UCR once or intermittent; (3) never abnormal UCR. Consenting RCT-eligible patients were randomised for immediate delivery from 34 weeks or expectant management until 37 weeks.

MAIN OUTCOME MEASURES

A composite adverse perinatal outcome (CAPO), defined as perinatal death, birth asphyxia or major neonatal morbidity.

RESULTS

The cohort consisted of 690 women. The study was halted prematurely for low RCT-inclusion rates (n = 40). In the RCT-eligible group, gestational age at delivery, birthweight and birthweight multiple of the median (MoM) (0.66, 95% confidence interval [CI] 0.59-0.72) were significantly lower and the CAPO (n = 50, 44%, p < 0.05) was more frequent. Among patients randomised for immediate delivery there was a near-significant lower birthweight (p = 0.05) and higher CAPO (p = 0.07). EFW MoM, pre-eclampsia, gestational hypertension and Doppler classification were independently associated with the CAPO (area under the curve 0.71, 95% CI 0.67-0.76).

CONCLUSIONS

Perinatal risk was effectively identified by low EFW MoM and UCR. Early delivery of SGA fetuses with an abnormal UCR at 34-36 weeks should only be performed in the context of clinical trials.

Management of hypertensive disorders in pregnancy: a Position Statement of the European Society of Hypertension Working Group 'Hypertension in Women'

Hypertensive disorders in pregnancy (HDP), remain the leading cause of adverse maternal, fetal, and neonatal outcomes. Epidemiological factors, comorbidities, assisted reproduction techniques, placental disorders, and genetic predisposition determine the burden of the disease. The pathophysiological substrate and the clinical presentation of HDP are multifarious. The latter and the lack of well designed clinical trials in the field explain the absence of consensus on disease management among relevant international societies. Thus, the usual clinical management of HDP is largely empirical. The current position statement of the Working Group 'Hypertension in Women' of the European Society of Hypertension (ESH) aims to employ the current evidence for the management of HDP, discuss the recommendations made in the 2023 ESH guidelines for the management of hypertension, and shed light on controversial issues in the field to stimulate future research.

Trends in antenatal corticosteroid administration: did our timing improve?

OBJECTIVES

We aimed to analyze trends in the rate of effective antenatal corticosteroid prophylaxis (ACS) administrations across a spectrum of typical diagnoses associated with preterm birth.

METHODS

In this retrospective study we utilized delivery data after ACS from 2014 to 2020 at Charité Berlin, Germany. We evaluated the rate of effective ACS administrations defined as ≤10 days between last dose of ACS and delivery as well as the rate of post-ACS births on/after 37 + 0 weeks. We explored conditions associated with high rates of ineffective ACS administrations (>10 days before delivery). We analyzed the trend of ACS-effectiveness during the study period in the overall cohort and in placental dysfunction and cervical insufficiency diagnoses.

RESULTS

The overall rate of effective ACS administrations was 42 % (709/1,672). The overall percentage of deliveries after/at 37 + 0 weeks following ACS administration was 19 % (343). Placenta previa, twin pregnancy and isthmocervical insufficiency were associated with ineffective ACS (19-34 % effective i.e. ≤10 days before delivery). The overall ratio of effective ACS applications rose over time (p=0.002). Over the course of this study ACS effectiveness increased in placental dysfunction and isthmocervical insufficiency diagnoses (p=0.028; p=0.001).

CONCLUSIONS

Compared to a previous publication we found a decrease of post-ACS deliveries after/at 37 + 0 weeks (19 vs. 27 %). Ineffective ACS administrations are still frequent in patients with placenta previa, twin pregnancy and isthmocervical insufficiency. It remains to be investigated in future trials if the introduction of new diagnostic tools such as soluble Fms-like tyrosinkinase-1/placental growth factor (sFlt-1/PlGF) testing and placental alpha-microglobulin-1 (PAMG-1) testing directly led to an increased ACS effectiveness.

Association of angiogenic factors (placental growth factor and soluble FMS-like tyrosine kinase-1) in preeclamptic women of African ancestry comorbid with HIV infection

BACKGROUND

Preeclampsia is a significant cause of maternal and fetal morbidity and mortality, particularly in low- and middle-income countries like South Africa.

AIM

The aim of our study was to investigate the association between placental growth factor (PlGF) and soluble FMS-like tyrosine kinase-1 (sFlt-1) in South African preeclamptic women of African ancestry, comorbid with HIV infection.

METHODS

The study population consisted of women attending a regional hospital in Durban, South Africa, stratified by pregnancy type (normotensive pregnant and preeclampsia) and HIV status. Preeclampsia was defined as new-onset hypertension and proteinuria. DNA was obtained from whole blood. The SNPs of interest were rs722503 in sFlt-1 and rs4903273 in PlGF.

RESULTS

Our findings suggest that single nucleotide polymorphisms of rs722503 analysis show no significant associations between the genotypic frequencies of rs722503 variants and preeclampsia risk in either HIV-negative or HIV-positive groups of women of African ancestry. Similarly, the rs493273 polymorphism showed no significant association with preeclampsia risk in either HIV-negative or HIV-positive pregnant women. Additionally, comparisons of dominant, recessive, and over-dominant allele models did not reveal significant associations. These findings suggest that these genetic variants may not significantly contribute to preeclampsia development in this African ancestry population. However, significant differences were observed in the rs4903273 genotype frequencies between normotensive and preeclamptic women, regardless of HIV status, over dominant alleles AA + GG vs AG showed a significant difference [OR = 2.706; 95% Cl (1.199-5.979); adjusted p = 0.0234*], also in normotensive compared to EOPE (OR = 2.804; 95% Cl (1.151-6.89) p = 0.0326* and LOPE (OR = 2.601; 95% Cl (1.0310-6.539) p = 0.0492*), suggesting that they may be the potential role of this variant in preeclampsia susceptibility.

CONCLUSION

The findings suggest that the rs722503 and rs493273 polymorphisms do not significantly contribute to preeclampsia susceptibility in HIV-negative or HIV-positive pregnant women. However, the rs4903273 genotype frequencies showed notable differences between normotensive and preeclamptic women, indicating a potential association with preeclampsia development in the African ancestry population irrespective of HIV status.

Placental neutrophil reverse trans-migration and maternal serum neutrophil extracellular trap expression in HIV infection co-morbid pre-eclampsia in women of African ancestry

Neutrophil extracellular traps (NETs) and placental neutrophil reverse transmigration (r-TM) are implicated in the pathogenesis of pre-eclampsia (PE). However, the role of the comorbidity of PE and human immunodeficiency virus (HIV) infection in placental neutrophil r-TM and serum NETs remains unknown. Human placental tissue (n = 160) and serum (n = 80) samples were obtained post-ethical approval and divided by pregnancy type and HIV status and across the study population. Immunohistochemistry and morphometry were performed to localize and quantify junctional adhesion molecule-C (JAM-C) expression as an inverse marker of neutrophil r-TM within placental villi. An enzyme-linked immunosorbent assay (ELISA) was performed to quantify the concentration of citrullinated histone H3 (cit-H3) as a marker of NETs. GraphPad Prism (version 8.0.2) was used to compare the results, and a p value of p < 0.05 was considered statistically significant. The localization of JAM-C was observed on the syncytiotrophoblasts (STBs) and endothelial cells of placental villi. The immunoexpression of JAM-C was elevated in PE vs. normotensive (N) placentae. In the exchange villi, JAM-C immunoexpression was higher in the N+ve vs. N-ve group. However, in PE comorbid HIV infection, JAM-C expression was lower in the PE+ve vs. PE-ve group. Citrullinated histone-H3 concentration was lower in the N+ve vs. N-ve group but elevated in early-onset PE (EOPE)+ve vs. late-onset PE (LOPE)+ve group. These results indicate that PE and HIV-infected placentae individually express elevated JAM-C, manifesting in less neutrophil r-TM. However, in exchange villi of PE comorbid with HIV infection reduced JAM-C enhances neutrophil r-TM, thus supporting the synergistic effect of PE comorbid with HIV.

Construction of a pathway-level model for preeclampsia based on gene expression data

Preeclampsia (PE) is a heterogeneous disease that seriously affects the health of mothers and fetuses. Lack of detection assays, its diagnosis and intervention are often delayed when the clinical symptoms are atypical. Using personalized pathway-based analysis and machine learning algorithms, we built a PE diagnosis model consisting of nine core pathways using multiple cohorts from the Gene Expression Omnibus database. The model showed an area under the receiver operating characteristic (AUROC) curve of 0.959 with the data from the placental tissue samples in the development cohort. In the two validation cohorts, the AUROCs were 0.898 and 0.876, respectively. The model also performed well with the maternal plasma data in another validation cohort (AUROC: 0.815). Moreover, we identified tyrosine-protein kinase Lck (LCK) as the hub gene in this model and found that LCK and pLCK proteins were downregulated in placentas from PE patients. The pathway-level model for PE can provide a novel direction to develop molecular diagnostic assay and investigate potential mechanisms of PE in future studies.

Systematic review of the complement components as potential biomarkers of pre-eclampsia: pitfalls and opportunities

The complement system (C) is a crucial component of the innate immune system. An increasing body of research has progressively shed light on the pivotal role of C in immunological tolerance at the feto-maternal interface. Excessive C activation or impaired C regulation may determine the onset of pregnancy-related pathological conditions, including pre-eclampsia (PE). Thus, several studies have investigated the presence of C components or split products in blood matrixes (i.e., plasma, serum), urine, and amniotic fluid in PE. In the current study, we systematically reviewed the currently available scientific literature reporting measurements of C components as circulating biomarkers in PE, based on a literature search using Pubmed, Scopus, and Embase databases. A total of 41 out of 456 studies were selected after full-text analysis. Fourteen studies (34.1%) were identified as measuring the blood concentrations of the classical pathway, 5 (12.1%) for the lectin pathway, 28 (68.3%) for the alternative pathway, 17 (41.5%) for the terminal pathway components, and 16 (39%) for C regulators. Retrieved results consistently reported C4, C3, and factor H reduction, and increased circulating levels of C4d, Bb, factor D, C3a, C5a, and C5b-9 in PE compared to normal pregnancies, depicting an overall scenario of excessive C activation and aberrant C regulation. With evidence of C activation and dysregulation, C-targeted therapy is an intriguing perspective in PE management. Moreover, we also discussed emerging pitfalls in C analysis, mainly due to a lack of experimental uniformity and biased cohort selection among different studies and laboratories, aiming to raise a more comprehensive awareness for future standardization.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024503070.

The ratio of soluble fms-like tyrosine kinase 1 to placental growth factor predicts time to delivery and mode of birth in patients with suspected preeclampsia: a secondary analysis of the INSPIRE trial

BACKGROUND

The ratio of soluble fms-like tyrosine kinase 1 to placental growth factor is a useful biomarker for preeclampsia. Since it is a measure of placental dysfunction, it could also be a predictor of clinical deterioration and fetal tolerance to intrapartum stress.

OBJECTIVE

We tested the hypothesis that soluble fms-like tyrosine kinase 1 to placental growth factor ratio predicts time to delivery. Secondary objectives were to examine associations between the soluble fms-like tyrosine kinase 1 to placental growth factor ratio and mode of birth, fetal distress, need for labor induction, and birthweight z score.

STUDY DESIGN

Secondary analysis of the INSPIRE trial, a randomized interventional study on prediction of preeclampsia/eclampsia in which women with suspected preeclampsia were recruited and their blood soluble fms-like tyrosine kinase 1 to placental growth factor ratio was assessed. We stratified participants into 3 groups according to the ratio result: category 1 (soluble fms-like tyrosine kinase 1 to placental growth factor ≤38); category 2 (soluble fms-like tyrosine kinase 1 to placental growth factor >38 and <85); and category 3 (soluble fms-like tyrosine kinase 1 to placental growth factor ≥85). We modeled time from soluble fms-like tyrosine kinase 1 to placental growth factor determination to delivery using Kaplan-Meier curves and compared the 3 ratio categories adjusting for gestational age at soluble fms-like tyrosine kinase 1 to placental growth factor determination and trial arm with Cox regression. The association between ratio category and mode of delivery, induction of labor, and fetal distress was assessed using a multivariable logistic regression adjusting for gestational age at sampling and trial arm. The association between birthweight z score and soluble fms-like tyrosine kinase 1 to placental growth factor ratio was evaluated using multiple linear regression. Subgroup analysis was conducted in women with no preeclampsia and spontaneous onset of labor; women with preeclampsia; and participants in the nonreveal arm.

RESULTS

Higher ratio categories were associated with a shorter latency from soluble fms-like tyrosine kinase 1 to placental growth factor determination to delivery (37 vs 13 vs 10 days for ratios categories 1-3 respectively), hazards ratio for category 3 ratio of 5.64 (95% confidence interval 4.06-7.84, P<.001). A soluble fms-like tyrosine kinase 1 to placental growth factor ratio ≥85 had specificity of 92.7% (95% confidence interval 89.0%-95.1%) and sensitivity of 54.72% (95% confidence interval, 41.3-69.5) for prediction of preeclampsia indicated delivery within 2 weeks. A ratio category 3 was also associated with decreased odds of spontaneous vaginal delivery (Odds ratio [OR] 0.47, 95% confidence interval 0.25-0.89); an almost 6-fold increased risk of emergency cesarean section (OR 5.89, 95% confidence interval 3.05-11.21); and a 2-fold increased risk for intrapartum fetal distress requiring operative delivery or cesarean section (OR 3.04, 95% confidence interval 1.53-6.05) when compared to patients with ratios ≤38. Higher ratio categories were also associated with higher odds of induction of labor when compared to ratios category 1 (category 2, OR 2.20, 95% confidence interval 1.02-4.76; category 3, OR 6.0, 95% confidence interval 2.01-17.93); and lower median birthweight z score. Within subgroups of women a) without preeclampsia and with spontaneous onset of labor and b) women with preeclampsia, the log ratio was significantly higher in patients requiring intervention for fetal distress or failure to progress compared to those who delivered vaginaly without intervention. In the subset of women with no preeclampsia and spontaneous onset of labor, those who required intervention for fetal distress or failure to progress had a significantly higher log ratio than those who delivered vaginaly without needing intervention.

CONCLUSION

The soluble fms-like tyrosine kinase 1 to placental growth factor ratio might be helpful in risk stratification of patients who present with suspected preeclampsia regarding clinical deterioration, intrapartum fetal distress, and mode of birth (including the need for intervention in labor).

Small RNAs in the pathogenesis of preeclampsia

Preeclampsia is a major contributor to maternal and fetal morbidity and mortality. The disorder can be classified into early- and late-onset subtypes, both of which evolve in two stages. The first stage comprises the development of pre-clinical, utero-placental malperfusion. Early and late utero-placental malperfusion have different causes and time courses. Early-onset preeclampsia (20 % of cases) is driven by dysfunctional placentation in the first half of pregnancy. In late-onset preeclampsia (80 % of cases), malperfusion is a consequence of placental compression within the confines of a limited uterine cavity. In both subtypes, the malperfused placenta releases stress signals into the maternal circulation. These stress signals trigger onset of the clinical syndrome (the second stage). Small RNA molecules, which are implicated in cellular stress responses in general, may be involved at different stages. Micro RNAs contribute to abnormal trophoblast invasion, immune dysregulation, angiogenic imbalance, and syncytiotrophoblast-derived extracellular vesicle signalling in preeclampsia. Transfer RNA fragments are placental signals known to be specifically involved in cell stress responses. Disorder-specific differences in small nucleolar RNAs and piwi-interacting RNAs have also been reported. Here, we summarise key small RNA advances in preeclampsia pathogenesis. We propose that existing small RNA classifications are unhelpful and that non-biased assessment of RNA expression, incorporation of non-annotated molecules and consideration of chemical modifications to RNAs may be important in elucidating preeclampsia pathogenesis.

Lipidomic signatures in patients with early-onset and late-onset Preeclampsia

BACKGROUND

Preeclampsia is a pregnancy-specific clinical syndrome and can be subdivided into early-onset preeclampsia (EOPE) and late-onset preeclampsia (LOPE) according to the gestational age of delivery. Patients with preeclampsia have aberrant lipid metabolism. This study aims to compare serum lipid profiles of normal pregnant women with EOPE or LOPE and screening potential biomarkers to diagnose EOPE or LOPE.

METHODS

Twenty normal pregnant controls (NC), 19 EOPE, and 19 LOPE were recruited in this study. Untargeted lipidomics based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to compare their serum lipid profiles.

RESULTS

The lipid metabolism profiles significantly differ among the NC, EOPE, and LOPE. Compared to the NC, there were 256 and 275 distinct lipids in the EOPE and LOPE, respectively. Furthermore, there were 42 different lipids between the LOPE and EOPE, of which eight were significantly associated with fetal birth weight and maternal urine protein. The five lipids that both differed in the EOPE and LOPE were DGTS (16:3/16:3), LPC (20:3), LPC (22:6), LPE (22:6), PC (18:5e/4:0), and a combination of them were a potential biomarker for predicting EOPE or LOPE. The receiver operating characteristic analysis revealed that the diagnostic power of the combination for distinguishing the EOPE from the NC and for distinguishing the LOPE from the NC can reach 1.000 and 0.992, respectively. The association between the lipid modules and clinical characteristics of EOPE and LOPE was investigated by the weighted gene co-expression network analysis (WGCNA). The results demonstrated that the main different metabolism pathway between the EOPE and LOPE was enriched in glycerophospholipid metabolism.

CONCLUSIONS

Lipid metabolism disorders may be a potential mechanism of the pathogenesis of preeclampsia. Lipid metabolites have the potential to serve as biomarkers in patients with EOPE or LOPE. Furthermore, lipid metabolites correlate with clinical severity indicators for patients with EOPE and LOPE, including fetal birth weight and maternal urine protein levels.

Active metabolomics identify potential functional metabolites for preeclampsia prevention

BACKGROUND

Preeclampsia (PE) is a leading cause of maternal and fetal morbidity and mortality, with limited effective clinical treatment options. Active metabolomics offers a promising approach to uncover metabolic changes in PE and identify potential biomarkers or therapeutic targets. This study performed untargeted metabolomics using LC-MS to compare serum samples from preeclampsia and normal pregnancies.

METHODS

We performed untargeted metabolomics using liquid chromatography-mass spectrometry (LC-MS) to compare serum samples from PE patients and normal pregnancies. We analyzed the alterations in metabolites and conducted functional experiments to assess the effects of LysoPE(16:0) on trophoblast cell invasion and migration. Mechanistic studies were performed to explore the potential targeting of GSK-3β by LysoPE(16:0).

RESULTS

Our metabolomics analysis revealed significant alterations in several metabolites, including lysophosphatidylcholines and organic acids. Notably, LysoPE(16:0) was found to be downregulated in the serum of PE patients. Functional experiments demonstrated that LysoPE(16:0) could promote trophoblast cell invasion and migration. Mechanistic studies suggest that the protective effect of LysoPE(16:0) against PE might be mediated through the modulation of the GSK-3β/β-Catenin pathway, with LysoPE(16:0) potentially targeting the GSK-3β protein.

CONCLUSIONS

Our findings highlight the potential role of LysoPE(16:0) in the pathophysiology of PE and its ability to modulate the GSK-3β/β-Catenin pathway. These results provide new insights into the metabolic changes associated with PE and suggest that LysoPE(16:0) could serve as a promising biomarker or therapeutic target for the prevention and treatment of PE.

Preeclampsia in pregnant women with COVID-19: a prospective cohort study from two tertiary hospitals in Southern Brazil

Background

COVID-19 is an infectious pathology that shows vascular changes during pregnancy, as well as in the placentas. The main objectives of this study were to estimate the prevalence and the risk factors for preeclampsia in hospitalized pregnant women with COVID-19. As well as comparing maternal and perinatal outcomes in hospitalized pregnant women with COVID-19 and preeclampsia with those without preeclampsia.

Methods

Prospective cohort study of 100 hospitalized pregnant women from two tertiary hospitals, diagnosed with COVID-19, and divided into two groups: PE+ group (pregnant women with COVID-19 and preeclampsia) and PE- group (pregnant women with COVID-19 without preeclampsia). These pregnant women had prevalence, risk factors, maternal and perinatal data analyzed.

Results

The prevalence of preeclampsia was 11%. Severe COVID-19 was the main risk factor for preeclampsia (OR = 8.18 [CI 1.53-43.52]), as well as fetal growth restriction was the main perinatal outcome (OR = 8.90 [CI 1.52-38.4]). Comorbidities were more frequent in the PE+ group (63.6% vs 31.5%, p = 0.03), as well as prematurity (81.8% vs 41.6%, p = 0.02), low birth weight (63.6% vs 24.7%, p = 0.01), and the need for neonatal intensive care admission of the newborn (63.6% vs 27.0%, p = 0.03). Pregnant women with PE had twice as long a length of stay in the intensive care unit (RR = 2.35 [CI 1.34-4.14]). Although maternal mortality was more frequent among pregnant women with PE, it was not statistically significant.

Conclusions

Prevalence of preeclampsia in hospitalized pregnant women with COVID-19 was 11%. Severe COVID-19 was the main risk factor for preeclampsia and associated comorbidities increased the risk for developing preeclampsia. Long length of stay in the intensive care unit was the main maternal outcome and fetal growth restriction was the main perinatal outcome of preeclampsia.

Maternal serum biomarkers of placental insufficiency at 24-28 weeks of pregnancy in relation to the risk of delivering small-for-gestational-age infant in Sylhet, Bangladesh: a prospective cohort study

BACKGROUND

Small-for-gestational-age (SGA), commonly caused by poor placentation, is a major contributor to global perinatal mortality and morbidity. Maternal serum levels of placental protein and angiogenic factors are changed in SGA. Using data from a population-based pregnancy cohort, we estimated the relationships between levels of second-trimester pregnancy-associated plasma protein-A (PAPP-A), placental growth factor (PlGF), and serum soluble fms-like tyrosine kinase-1 (sFlt-1) with SGA.

METHODS

Three thousand pregnant women were enrolled. Trained health workers prospectively collected data at home visits. Maternal blood samples were collected, serum aliquots were prepared and stored at -80℃. Included in the analysis were 1,718 women who delivered a singleton live birth baby and provided a blood sample at 24-28 weeks of gestation. We used Mann-Whitney U test to examine differences of the median biomarker concentrations between SGA (< 10th centile birthweight for gestational age) and appropriate-for-gestational-age (AGA). We created biomarker concentration quartiles and estimated the risk ratios (RRs) and 95% confidence intervals (CIs) for SGA by quartiles separately for each biomarker. A modified Poisson regression was used to determine the association of the placental biomarkers with SGA, adjusting for potential confounders.

RESULTS

The median PlGF level was lower in SGA pregnancies (934 pg/mL, IQR 613-1411 pg/mL) than in the AGA (1050 pg/mL, IQR 679-1642 pg/mL; p < 0.001). The median sFlt-1/PlGF ratio was higher in SGA pregnancies (2.00, IQR 1.18-3.24) compared to AGA pregnancies (1.77, IQR 1.06-2.90; p = 0.006). In multivariate regression analysis, women in the lowest quartile of PAPP-A showed 25% higher risk of SGA (95% CI 1.09-1.44; p = 0.002). For PlGF, SGA risk was higher in women in the lowest (aRR 1.40, 95% CI 1.21-1.62; p < 0.001) and 2nd quartiles (aRR 1.30, 95% CI 1.12-1.51; p = 0.001). Women in the highest and 3rd quartiles of sFlt-1 were at reduced risk of SGA delivery (aRR 0.80, 95% CI 0.70-0.92; p = 0.002, and aRR 0.86, 95% CI 0.75-0.98; p = 0.028, respectively). Women in the highest quartile of sFlt-1/PlGF ratio showed 18% higher risk of SGA delivery (95% CI 1.02-1.36; p = 0.025).

CONCLUSIONS

This study provides evidence that PAPP-A, PlGF, and sFlt-1/PlGF ratio measurements may be useful second-trimester biomarkers for SGA.

Identifying molecular subgroups of patients with preeclampsia through bioinformatics

Preeclampsia (PE) is a pregnancy-related disorder associated with serious complications. Its molecular mechanisms remain undefined; hence, we aimed to identify molecular subgroups of patients with PE using bioinformatics to aid treatment strategies. R software was used to analyze gene expression data of 130 patients with PE and 138 healthy individuals from the Gene Expression Omnibus database. Patients with PE were divided into two molecular subgroups using the unsupervised clustering learning method. Clinical feature analysis of subgroups using weighted gene co-expression network analysis showed that the patients in subgroup I were primarily characterized by early onset of PE, severe symptoms at disease onset, and induced labor as the main delivery method. Patients in subgroup II primarily exhibited late PE onset, relatively mild symptoms, and natural delivery as the main delivery method. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses revealed that the significant enrichment of calcium ion channels in subgroup II indicated the potential efficacy of calcium antagonists and magnesium sulfate therapy. In conclusion, the establishment of PE molecular subgroups can aid in diagnosing and treating PE.

Model construction and application for predicting pre-eclampsia by Sonoclot coagulation analyzer

Maternal age has significantly increased among Chinese women, thereby posing risk of pregnancy-related complications. Preeclampsia is a leading cause of maternal and perinatal morbidity and mortality, and coagulation analysis in conjunction with clinical signs and symptoms are generally used for its diagnosis with limited efficacy. Sonoclot coagulation analyzer is effective in assessing coagulation function used during cerebral surgery and cardiovascular surgery. However, its use has not been explored in preeclampsia. Here, we investigated the potential use of Sonoclot in diagnosing preeclampsia in obstetrics cases. Subjects meeting the screening criteria were divided either into a test group or a control group, according to whether they were preeclamptic or not. We recorded the Sonoclot-derived coagulation and the routine coagulation parameters including platelet function (PF), activated clotting time (ACT) and clot rate (CR), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (FIB), and platelet count. Regression analysis was done on the relevant parameters to assess the feasibility of Sonoclot analyzer in preeclampsia diagnosis. In parallel, changes in preeclampsia lncRNAs was also evaluated. Significant differences were recorded in PT and ACT between the two groups. In the monovariant logistic regression, PT and ACT appeared to be reliable predictor variables. In the multinomial logistic regression, a total of five regression steps were performed with decreasing AIC values. The K-fold cross validation resulted in an accuracy rate (ACC) of 77.5%, a false positive rate of 16.4%, and a false negative rate of 33.2%. lncRNAs ANRIL and HOXD-AS1 were found deregulated. Our findings indicate that Sonoclot may be useful for diagnosis of preeclampsia in obstetrics.

A Comparison of Obstetric Outcomes in Antiphospholipid Syndrome Among Pregnant Women With Systemic Lupus Erythematosus

Objective The aim of this study was to evaluate the maternal and perinatal outcomes in systemic lupus erythematosus (SLE) women with antiphospholipid syndrome (APS). Methods This retrospective case-control study was conducted among pregnant women with SLE with and without APS. Group A included SLE patients with APS, whereas group B included pregnant SLE women without APS. Data were expressed as mean ± standard deviation (SD). Frequency and percentage were computed for categorical data. The chi-square test was used to analyze the difference between categorical data. Results Out of 125 cases of SLE, APS was found in 72 (57.6%) women. Almost 95.8% of patients were on treatment (aspirin and enoxaparin) in group A. Preterm delivery (31.89±7.36 versus 34.46±4.97; p=0.021) and termination of pregnancy (18.1% [13/72] versus 5.7% [3/53]; p=0.04) were statistically significant in group A. Among these terminations, second-trimester intrauterine death is found to be more in group A (SLE with APS) (16.7% [12/72]) as compared to group B (SLE without APS) (5.7% [3/53]) with a p-value of 0.05. Perinatal outcomes including NICU admissions (39% [23/59] versus 24% [12/50]; p=0.071) and neonatal death (12.3% [7/57]; p=0.015) were also found to be statistically significant between the two groups. Conclusion APS with SLE is associated with adverse pregnancy outcomes such as preterm birth, termination of pregnancy due to second-trimester fetal loss, more NICU admission, and neonatal deaths when compared to the control group. Hence, pregnancies with APS with SLE require vigilant monitoring and frequent follow-ups to ensure a positive pregnancy outcome.

Prediction of preterm birth in women with fetal growth restriction - Is the weekly change in sFlt-1/PlGF ratio or PlGF levels useful?

INTRODUCTION

To assess the rate of change in soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio and PlGF levels per week compared to a single sFlt-1/PlGF ratio or PlGF level to predict preterm birth for pregnancies complicated by fetal growth restriction.

MATERIAL AND METHODS

A prospective cohort study of pregnancies complicated by isolated fetal growth restriction. Maternal serum PlGF levels and the sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. We investigated the utility of PlGF levels, sFlt-1/PlGF ratio, change in PlGF levels per week or sFlt-1/PlGF ratio per week. Cox-proportional hazard models and Harrell's C concordance statistic were used to evaluate the effect of biomarkers on time to preterm birth.

RESULTS

The total study cohort was 158 pregnancies comprising 91 (57.6%) with fetal growth restriction and 67 (42.4%) with appropriate for gestational age controls. In the fetal growth restriction cohort, sFlt-1/PlGF ratio and PlGF levels significantly affected time to preterm birth (Harrell's C: 0.85-0.76). The rate of increase per week of the sFlt-1/PlGF ratio (hazard ratio [HR] 3.91, 95% confidence interval [CI]: 1.39-10.99, p = 0.01, Harrell's C: 0.74) was positively associated with preterm birth but change in PlGF levels per week was not (HR 0.65, 95% CI: 0.25-1.67, p = 0.37, Harrell's C: 0.68).

CONCLUSIONS

Both a high sFlt-1/PlGF ratio and low PlGF levels are predictive of preterm birth in women with fetal growth restriction. Although the rate of increase of the sFlt-1/PlGF ratio predicts preterm birth, it is not superior to either a single elevated sFlt-1/PlGF ratio or low PlGF level.

Predicting Preterm Birth Using Proteomics

The complexity of preterm birth (PTB), both spontaneous and medically indicated, and its various etiologies and associated risk factors pose a significant challenge for developing tools to accurately predict risk. This review focuses on the discovery of proteomics signatures that might be useful for predicting spontaneous PTB or preeclampsia, which often results in PTB. We describe methods for proteomics analyses, proteomics biomarker candidates that have so far been identified, obstacles for discovering biomarkers that are sufficiently accurate for clinical use, and the derivation of composite signatures including clinical parameters to increase predictive power.

Signs or symptoms of suspected preeclampsia - A retrospective national database study of prevalence, costs, and outcomes

BACKGROUND

Most patients with signs or symptoms (s/s) of suspected preeclampsia are not diagnosed with preeclampsia. We sought to determine and compare the prevalence of s/s, pregnancy outcomes, and costs between patients with and without diagnosed preeclampsia.

METHODS

This retrospective cohort study analyzed a large insurance research database. Pregnancies with s/s of preeclampsia versus a confirmed preeclampsia diagnosis were identified using International Classification of Diseases codes. S/s include hypertension, proteinuria, headache, visual symptoms, edema, abdominal pain, and nausea/vomiting. Pregnancies were classed as 1) s/s of preeclampsia without a confirmed preeclampsia diagnosis (suspicion only), 2) s/s with a confirmed diagnosis (preeclampsia with suspicion), 3) diagnosed preeclampsia without s/s recorded (preeclampsia only), and 4) no s/s, nor preeclampsia diagnosis (control).

RESULTS

Of 1,324,424 pregnancies, 29.2 % had ≥1 documented s/s of suspected preeclampsia, and 14.2 % received a preeclampsia diagnosis. Hypertension and headache were the most common s/s, leading 20.2 % and 9.2 % pregnancies developed to preeclampsia diagnosis, respectively. Preeclampsia, with or without suspicion, had the highest rates of hypertension-related severe maternal morbidity (HR [95 % CI]: 3.0 [2.7, 3.2] and 3.6 [3.3, 4.0], respectively) versus controls. A similar trend was seen in neonatal outcomes such as preterm delivery and low birth weight. Cases in which preeclampsia was suspected but not confirmed had the highest average total maternal care costs ($6096 [95 % CI: 602, 6170] over control).

CONCLUSION

There is a high prevalence but poor selectivity of traditional s/s of preeclampsia, highlighting a clinical need for improved screening method and cost-effectiveness disease management.

Plasma soluble fms-like tyrosine kinase 1 to placental growth factor ratio of 11.5 multiples of median predicts preeclampsia with severe features within 2 weeks of testing

BACKGROUND

Angiogenic imbalances, characterized by an excess of antiangiogenic factors (soluble fms-like tyrosine kinase 1) and reduced angiogenic factors (vascular endothelial growth factor and placental growth factor), contribute to the mechanisms of disease in preeclampsia. The ratio of soluble fms-like tyrosine kinase 1 to placental growth factor has been used as a biomarker for preeclampsia, but the cutoff values may vary with gestational age and assay platform.

OBJECTIVE

This study aimed to compare multiples of the median of the maternal plasma soluble fms-like tyrosine kinase 1 to placental growth factor ratio, soluble fms-like tyrosine kinase 1, placental growth factor, and conventional clinical and laboratory values in their ability to predict preeclampsia with severe features.

STUDY DESIGN

We conducted a cohort study across 18 United States centers involving hospitalized individuals with hypertension between 23 and 35 weeks' gestation. Receiver operating characteristic curve analyses of maternal plasma biomarkers, highest systolic or diastolic blood pressures, and laboratory values at enrollment were performed for the prediction of preeclampsia with severe features. The areas under the curve were compared, and quasi-Poisson regression models were fitted to estimate relative risks. The primary outcome was preeclampsia with severe features within 2 weeks of enrollment. Secondary outcomes were a composite of severe adverse maternal outcomes (elevated liver enzymes, low platelets count, placental abruption, eclampsia, disseminated intravascular coagulation, and pulmonary edema) and a composite of severe adverse perinatal outcomes (birth weight below the third percentile, very preterm birth [<32 weeks' gestation], and fetal or neonatal death).

RESULTS

Of the 543 individuals included in the study, preeclampsia with severe features within 2 weeks was observed in 33.1% (n=180) of them. A receiver operating characteristic curve-derived cutoff of 11.5 multiples of the median for the soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio provided good sensitivity (90.6%), specificity (76.9%), positive predictive value (66.0%), negative predictive value (94.3%), positive likelihood ratio (3.91), negative likelihood ratio (0.12), and accuracy (81.4%) for preeclampsia with severe features within 2 weeks. This cutoff was used to compare test positive cases (≥ cutoff) and test negative cases (< cutoff). Preeclampsia with severe features (66.0% vs 5.7%; P<.001) and composites of severe adverse maternal (8.11% vs 2.7%; P=.006) or perinatal (41.3% vs 10.14%; P=.001) outcomes within 2 weeks were more frequent in test positive cases than in test negative cases. A soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio ≥11.5 multiples of the median was independently associated with preeclampsia with severe features (adjusted incidence rate ratio, 9.08; 95% confidence interval, 6.11-14.06; P<.001) and a composite of severe adverse perinatal outcomes (adjusted incidence rate ratio, 9.42; 95% confidence interval, 6.36-14.53; P<.001) but not with a composite of severe adverse maternal outcomes (adjusted incidence rate ratio, 2.20; 95% confidence interval, 0.95-5.54; P=.08). The area under the curve for the soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio in multiples of the median (0.91; 95% confidence interval, 0.89-0.94) for preeclampsia with severe features within 2 weeks was significantly higher (P<.001 for all comparisons) than either plasma biomarker alone or any other parameter with the exception of absolute soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio values.

CONCLUSION

A soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio ≥11.5 multiples of the mean among hospitalized patients with hypertension between 23 and 35 week's gestation predicts progression to preeclampsia with severe features and severe adverse perinatal outcomes within 2 weeks.

A Galectin-9-Driven CD11chigh Decidual Macrophage Subset Suppresses Uterine Vascular Remodeling in Preeclampsia

BACKGROUND

Preeclampsia is a serious disease of pregnancy that lacks early diagnosis methods or effective treatment, except delivery. Dysregulated uterine immune cells and spiral arteries are implicated in preeclampsia, but the mechanistic link remains unclear.

METHODS

Single-cell RNA sequencing and spatial transcriptomics were used to identify immune cell subsets associated with preeclampsia. Cell-based studies and animal models including conditional knockout mice and a new preeclampsia mouse model induced by recombinant mouse galectin-9 were applied to validate the pathogenic role of a CD11chigh subpopulation of decidual macrophages (dMφ) and to determine its underlying regulatory mechanisms in preeclampsia. A retrospective preeclampsia cohort study was performed to determine the value of circulating galectin-9 in predicting preeclampsia.

RESULTS

We discovered a distinct CD11chigh dMφ subset that inhibits spiral artery remodeling in preeclampsia. The proinflammatory CD11chigh dMφ exhibits perivascular enrichment in the decidua from patients with preeclampsia. We also showed that trophoblast-derived galectin-9 activates CD11chigh dMφ by means of CD44 binding to suppress spiral artery remodeling. In 3 independent preeclampsia mouse models, placental and plasma galectin-9 levels were elevated. Galectin-9 administration in mice induces preeclampsia-like phenotypes with increased CD11chigh dMφ and defective spiral arteries, whereas galectin-9 blockade or macrophage-specific CD44 deletion prevents such phenotypes. In pregnant women, increased circulating galectin-9 levels in the first trimester and at 16 to 20 gestational weeks can predict subsequent preeclampsia onset.

CONCLUSIONS

These findings highlight a key role of a distinct perivascular inflammatory CD11chigh dMφ subpopulation in the pathogenesis of preeclampsia. CD11chigh dMφ activated by increased galectin-9 from trophoblasts suppresses uterine spiral artery remodeling, contributing to preeclampsia. Increased circulating galectin-9 may be a biomarker for preeclampsia prediction and intervention.

Systemic Lupus Erythematosus and Pregnancy Complications and Outcomes: A Mendelian Randomization Study and Retrospective Validation

Introduction

Previous studies have shown that pregnant women with systemic lupus erythematosus (SLE) tend to have a higher risk of adverse pregnancy outcomes, but the potential causal role remained unclear. In this study, we aimed to investigate the causal relationship between SLE and some common pregnancy complications and outcomes using two-sample Mendelian randomization (MR).

Methods

The genetic tools were derived from genome-wide association studies of SLE and pregnancy complications and outcomes. MR analysis was performed using inverse variance weighting as primary method. Sensitivity analyses were performed to evaluate the robustness of the results. A retrospective analysis was conducted on 200 pregnant women with SLE and a control group of pregnant women delivering at Tongji Hospital.

Results

In the results, we found that genetic susceptibility to SLE was associated with a higher risk of gestational diabetes mellitus (OR = 1.028, 95% CI: 1.006-1.050), premature delivery (OR = 1.039, 95% CI: 1.013-1.066), polyhydramnios (OR = 1.075, 95% CI: 1.004-1.151) and premature rupture of membranes (OR = 1.030, 95% CI: 1.001-1.060). Some of the retrospective analysis results align with the findings from the MR analysis, indicating that pregnant women with SLE have a higher risk of developing gestational diabetes mellitus and preterm birth. Additionally, although MR analysis did not reveal a causal relationship between SLE and preeclampsia/eclampsia, retrospective analysis discovered that SLE pregnant women are more susceptible to developing preeclampsia/eclampsia (OR = 2.935, 95% CI: 1.118-7.620).

Conclusion

Our study findings suggest a potential causal relationship between SLE and increased risks of gestational diabetes and preterm delivery. Clinical data indicate that pregnant women with SLE are more prone to developing preeclampsia/eclampsia. Clinicians need to be vigilant about the occurrence of these conditions when managing pregnant women with SLE.

Acute response to pathogens in the early human placenta at single-cell resolution

The placenta is a selective maternal-fetal barrier that provides nourishment and protection from infections. However, certain pathogens can attach to and even cross the placenta, causing pregnancy complications with potential lifelong impacts on the child's health. Here, we profiled at the single-cell level the placental responses to three pathogens associated with intrauterine complications-Plasmodium falciparum, Listeria monocytogenes, and Toxoplasma gondii. We found that upon exposure to the pathogens, all placental lineages trigger inflammatory responses that may compromise placental function. Additionally, we characterized the responses of fetal macrophages known as Hofbauer cells (HBCs) to each pathogen and propose that they are the probable niche for T. gondii. Finally, we revealed how P. falciparum adapts to the placental microenvironment by modulating protein export into the host erythrocyte and nutrient uptake pathways. Altogether, we have defined the cellular networks and signaling pathways mediating acute placental inflammatory responses that could contribute to pregnancy complications.

Excessive endometrial PlGF- Rac1 signalling underlies endometrial cell stiffness linked to pre-eclampsia

Cell stiffness is regulated by dynamic interaction between ras-related C3 botulinum toxin substrate 1 (Rac1) and p21 protein-activated kinase 1 (PAK1) proteins, besides other biochemical and molecular regulators. In this study, we investigated how the Placental Growth Factor (PlGF) changes endometrial mechanics by modifying the actin cytoskeleton at the maternal interface. We explored the global effects of PlGF in endometrial stromal cells (EnSCs) using the concerted approach of proteomics, atomic force microscopy (AFM), and electrical impedance spectroscopy (EIS). Proteomic analysis shows PlGF upregulated RhoGTPases activating proteins and extracellular matrix organization-associated proteins in EnSCs. Rac1 and PAK1 transcript levels, activity, and actin polymerization were significantly increased with PlGF treatment. AFM further revealed an increase in cell stiffness with PlGF treatment. The additive effect of PlGF on actin polymerization was suppressed with siRNA-mediated inhibition of Rac1, PAK1, and WAVE2. Interestingly, the increase in cell stiffness by PlGF treatment was pharmacologically reversed with pravastatin, resulting in improved trophoblast cell invasion. Taken together, aberrant PlGF levels in the endometrium can contribute to an altered pre-pregnancy maternal microenvironment and offer a unifying explanation for the pathological changes observed in conditions such as pre-eclampsia (PE).

Comparison of competing-risks model with angiogenic factors in midgestation screening for preterm growth-related neonatal morbidity

OBJECTIVES

First, to evaluate the predictive performance for preterm growth-related neonatal morbidity of a high soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio or low PlGF at midgestation and, second, to compare the performance of a high sFlt-1/PlGF ratio or low PlGF with that of the competing-risks model for small-for-gestational age (SGA), utilizing a combination of maternal risk factors, sonographic estimated fetal weight and uterine artery pulsatility index.

METHODS

This was a prospective observational study in women attending for a routine hospital visit at 19-24 weeks' gestation in two maternity hospitals in England. The visit included recording of maternal demographic characteristics and medical history, carrying out an ultrasound scan and measuring serum PlGF and sFlt-1. The primary outcome was delivery < 32 and < 37 weeks' gestation of a SGA neonate with birth weight < 10th or < 3rd percentile, combined with neonatal unit (NNU) admission for ≥ 48 h or a composite of major neonatal morbidity. The detection rates in screening by PlGF < 10th percentile, sFlt-1/PlGF ratio > 90th percentile and the competing-risks model for SGA were estimated and then compared using McNemar's test.

RESULTS

In the study population of 40 241 women, prediction of preterm growth-related neonatal morbidity provided by the competing-risks model for SGA was superior to that of screening by low PlGF concentration or high sFlt-1/PlGF ratio. For example, at a screen-positive rate of 10.0%, as defined by the sFlt-1/PlGF ratio > 90th percentile, the competing-risks model predicted 70.1% (95% CI, 61.0-79.2%) of SGA < 10th percentile and 76.9% (95% CI, 67.6-86.3%) of SGA < 3rd percentile with NNU admission for ≥ 48 h delivered < 32 weeks' gestation. The respective values for SGA with major neonatal morbidity were 73.8% (95% CI, 64.4-83.2%) and 77.9% (95% CI, 68.0-87.8%). These were significantly higher than the respective values of 35.1% (95% CI, 25.6-44.6%), 35.9% (95% CI, 25.3-46.5%), 38.1% (95% CI, 27.7-48.5%) and 39.7% (95% CI, 28.1-51.3%) achieved by the application of the sFlt-1/PlGF ratio > 90th percentile (all P < 0.0001).

CONCLUSION

At midgestation, the prediction of growth-related neonatal morbidity by the competing-risks model for SGA is superior to that of a high sFlt-1/PlGF ratio or low PlGF. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Novel Associations Between Mid-Pregnancy Cardiovascular Biomarkers and Preeclampsia: An Explorative Nested Case-Control Study

Prediction of women at high risk of preeclampsia is important for prevention and increased surveillance of the disease. Current prediction models need improvement, particularly with regard to late-onset preeclampsia. Preeclampsia shares pathophysiological entities with cardiovascular disease; thus, cardiovascular biomarkers may contribute to improving prediction models. In this nested case-control study, we explored the predictive importance of mid-pregnancy cardiovascular biomarkers for subsequent preeclampsia. We included healthy women with singleton pregnancies who had donated blood in mid-pregnancy (~ 18 weeks' gestation). Cases were women with subsequent preeclampsia (n = 296, 10% of whom had early-onset preeclampsia [< 34 weeks]). Controls were women who had healthy pregnancies (n = 333). We collected data on maternal, pregnancy, and infant characteristics from medical records. We used the Olink cardiovascular II panel immunoassay to measure 92 biomarkers in the mid-pregnancy plasma samples. The Boruta algorithm was used to determine the predictive importance of the investigated biomarkers and first-trimester pregnancy characteristics for the development of preeclampsia. The following biomarkers had confirmed associations with early-onset preeclampsia (in descending order of importance): placental growth factor (PlGF), matrix metalloproteinase (MMP-12), lectin-like oxidized LDL receptor 1, carcinoembryonic antigen-related cell adhesion molecule 8, serine protease 27, pro-interleukin-16, and poly (ADP-ribose) polymerase 1. The biomarkers that were associated with late-onset preeclampsia were BNP, MMP-12, alpha-L-iduronidase (IDUA), PlGF, low-affinity immunoglobulin gamma Fc region receptor II-b, and T cell surface glycoprotein. Our results suggest that MMP-12 is a promising novel preeclampsia biomarker. Moreover, BNP and IDUA may be of value in enhancing prediction of late-onset preeclampsia.

Prognostic value of angiogenic markers in pregnancy with fetal growth restriction

OBJECTIVE

Pregnancies with fetal growth restriction (FGR) are at increased risk for pre-eclampsia. Angiogenic markers including soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are altered in pregnancies complicated by FGR, but their utility for predicting pre-eclampsia in growth-restricted pregnancies is uncertain. This study aimed to evaluate the prognostic value of angiogenic markers for predicting the development of pre-eclampsia in pregnancies with FGR and suspected pre-eclampsia.

METHODS

This was a retrospective study of singleton pregnancies with FGR, defined according to Delphi consensus criteria, which underwent sampling of sFlt-1 and PlGF for suspicion of pre-eclampsia at the Medical University of Vienna, Vienna, Austria, between 2013 and 2020. Women with an established diagnosis of pre-eclampsia at sampling were excluded. Cox regression analysis and logistic regression analysis were performed to evaluate the association of angiogenic markers with the development of pre-eclampsia at various timepoints.

RESULTS

In this cohort of 93 women, pre-eclampsia was diagnosed in 14 (15.1%) women within 1 week after sampling, 21 (22.6%) within 2 weeks after sampling and 38 (40.9%) at any time after assessment. The sFlt-1/PlGF ratio consistently showed a stronger association with the development of pre-eclampsia compared to sFlt-1 or PlGF alone (pre-eclampsia within 1 week: area under the receiver-operating-characteristics curve, 0.87 vs 0.82 vs 0.72). Models including the sFlt-1/PlGF ratio were associated more strongly with pre-eclampsia hazard compared to models including sFlt-1 or PlGF alone (concordance index, 0.790 vs 0.759 vs 0.755). The risk classification capability of the sFlt-1/PlGF ratio decreased after the 2-week timepoint. The established cut-off value for the sFlt-1/PlGF ratio of < 38 was effective for ruling out pre-eclampsia within 2 weeks, with a negative predictive value of 0.933 and sensitivity of 0.952.

CONCLUSIONS

Use of the sFlt-1/PlGF ratio is preferrable to the use of PlGF alone for the prediction of pre-eclampsia in pregnancies with FGR. Established cut-offs for ruling out the development of pre-eclampsia in the short term seem to be effective in these patients. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Vascular endothelial growth factors and risk of cardio-renal events: Results from the CREDENCE trial

BACKGROUND

Circulating concentrations of vascular endothelial growth factor (VEGF) family members may be abnormally elevated in type 2 diabetes (T2D). The roles of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFLT-1), and VEGF-A in cardio-renal complications of T2D are not established.

METHOD

The 2602 individuals with diabetic kidney disease (DKD) from the Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation trial were randomized to receive canagliflozin or placebo and followed for incident cardio-renal outcomes. PlGF, sFLT-1, and VEGF-A were measured at baseline, year 1, and year 3. Primary outcome was a composite of end-stage kidney disease, doubling of the serum creatinine, or renal/cardiovascular death. Cox proportional hazard regression was used to investigate the association between biomarkers with adverse clinical events.

RESULTS

At baseline, individuals with higher PlGF levels had more prevalent cardiovascular disease compared to those with lower values. Treatment with canagliflozin did not meaningfully change PlGF, sFLT-1, and VEGF-A concentrations at years 1 and 3. In a multivariable model, 1 unit increases in baseline log PlGF (hazard ratio [HR]: 1.76, 95% confidence interval [CI]: 1.23, 2.54, P-value = .002), sFLT-1 (HR: 3.34, [95% CI: 1.71, 6.52], P-value < .001), and PlGF/sFLT-1 ratio (HR: 4.83, [95% CI: 0.86, 27.01], P-value = .07) were associated with primary composite outcome, while 1 unit increase in log VEGF-A did not increase the risk of primary outcome (HR: 0.96 [95% CI: 0.81, 1.07]). Change by 1 year of each biomarker was also assessed: HR (95% CI) of primary composite outcome was 2.45 (1.70, 3.54) for 1 unit increase in 1-year concentration of log PlGF, 4.19 (2.18, 8.03) for 1 unit increase in 1-year concentration of log sFLT-1, and 21.08 (3.79, 117.4) for 1 unit increase in 1-year concentration of log PlGF/sFLT-1. Increase in 1-year concentrations of log VEGF-A was not associated with primary composite outcome (HR: 1.08, [95% CI: 0.93, 1.24], P-value = .30).

CONCLUSIONS

People with T2D and DKD with elevated levels of PlGF, sFLT-1, and PlGF/sFLT-1 ratio were at a higher risk for cardiorenal events. Canagliflozin did not meaningfully decrease concentrations of PlGF, sFLT-1, and VEGF-A.

CLINICAL TRIAL

CREDENCE, https://clinicaltrials.gov/ct2/show/NCT02065791.

Placental growth factor and fetoplacental Doppler indices in combination predict preterm birth reliably in pregnancies complicated by fetal growth restriction

OBJECTIVE

To assess the association between placental biomarkers (placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1)/PlGF ratio) and fetoplacental Doppler indices (umbilical artery (UA) pulsatility index (PI) and uterine artery (UtA) PI) in various combinations for predicting preterm birth (PTB) in pregnancies complicated by fetal growth restriction (FGR).

METHODS

This was a prospective observational cohort study, performed at Mater Mother's Hospital in Brisbane, Queensland, Australia, from May 2022 to June 2023, of pregnancies complicated by FGR and appropriate-for-gestational-age (AGA) pregnancies. Maternal serum PlGF levels, sFlt-1/PlGF ratio, UA-PI and UtA-PI were measured at 2-4-weekly intervals from recruitment until delivery. Harrell's concordance statistic (Harrell's C) was used to evaluate multivariable Cox proportional hazards regression models featuring various combinations of placental biomarkers and fetoplacental Doppler indices to ascertain the best combination to predict PTB (< 37 weeks). Multivariable Cox regression models were used with biomarkers as time-varying covariates.

RESULTS

The study cohort included 320 singleton pregnancies, comprising 179 (55.9%) affected by FGR, defined according to a Delphi consensus, and 141 (44.1%) with an AGA fetus. In the FGR cohort, both low PlGF levels and elevated sFlt-1/PlGF ratio were associated with significantly shorter time to PTB. Low PlGF was a better predictor of PTB than was either sFlt-1/PlGF ratio or a combination of PlGF and sFlt-1/PlGF ratio (Harrell's C, 0.81, 0.78 and 0.79, respectively). Although both Doppler indices were significantly associated with time to PTB, in combination they were better predictors of PTB than was either UA-PI > 95th centile or UtA-PI > 95th centile alone (Harrell's C, 0.82, 0.75 and 0.76, respectively). Predictive utility for PTB was best when PlGF < 100 ng/L, UA-PI > 95th centile and UtA-PI > 95th centile were combined (Harrell's C, 0.88) (hazard ratio, 32.99; 95% CI, 10.74-101.32).

CONCLUSIONS

Low maternal serum PlGF level (< 100 ng/L) and abnormal fetoplacental Doppler indices (UA-PI > 95th centile and UtA-PI > 95th centile) in combination have the greatest predictive utility for PTB in pregnancies complicated by FGR. Their assessment may help guide clinical management of these complex pregnancies. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.