An Elevated Maternal Plasma Soluble fms-Like Tyrosine Kinase-1 to Placental Growth Factor Ratio at Midtrimester Is a Useful Predictor for Preeclampsia

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.

Correlation of sFlt/PlGF ratio with severity of preeclampsia in an Indian population

Background

Preeclampsia affects 2% to 8% of pregnant women and significantly increases the risk for maternal and perinatal morbidity, especially in low- and middle-income countries. There is increasing evidence to support the use of biochemical markers such as placental growth factor and soluble fms-like tyrosine kinase-1 in predicting the severity of preeclampsia and to rule out severe disease in clinical conditions masquerading as severe preeclampsia.

OBJECTIVE

This study aimed to assess the role of the sFlt-1/PlGF ratio in predicting adverse perinatal and maternal outcomes in women with preeclampsia in a South Asian population with a higher rate of the disease and its associated complications.

STUDY DESIGN

This was a prospective cohort study of women diagnosed with preeclampsia or suspected to have preeclampsia who underwent biophysical and biochemical investigations to measure the severity, including determining maternal hemodynamic indices, mean arterial pressure, fetal biometric and Doppler parameters, and soluble fms-like tyrosine kinase-1 and placental growth factor levels. The performance of these markers, individually or in combination, in predicting adverse perinatal and maternal outcomes was then assessed using receiver operating characteristic curve analysis. An adverse maternal outcome was defined as 1 or more of severe hypertension; admission to the intensive care unit; eclampsia; placental abruption; hemolysis, elevated liver enzymes, low-platelet count syndrome; disseminated intravascular coagulation; platelets <100×10⁹/L; creatinine >1.1 mg/dL; and alanine aminotransferase >100 U/L. An adverse perinatal outcome was defined as 1 or more of preterm birth ≤34+0 weeks' gestation, neonatal intensive care unit admission for >48 hours, respiratory distress syndrome, intraventricular hemorrhage, hypoxic ischemic encephalopathy, necrotizing enterocolitis, retinopathy of prematurity, and confirmed fetal infection.

RESULTS

We recruited 91 women with preeclampsia with a mean gestational age of 30.63±2.86 weeks. Women who had adverse maternal events had higher median maternal concentrations of soluble fms-like tyrosine kinase (11,500.0 pg/mL vs 3051.0 pg/mL; P<.001), lower concentrations of placental growth factor (44.88 pg/mL vs 148.50 pg/mL; P<.001), and a higher sFlt-1/PlGF ratio (306.22 vs 30.63; P<.001) than women who did not. Pregnancies with an adverse perinatal outcome also had a higher soluble fms-like tyrosine kinase concentration (12,100.0 pg/mL vs 3051.0 pg/mL; P<.001), lower placental growth factor concentration (27.2 pg/mL vs 148.50 pg/mL; P<.001), and higher sFlt-1/PlGF ratio (378.45.4 vs 30.63; P<.001). The area under the receiver operating characteristic curve showed that soluble fms-like tyrosine kinase and placental growth factor were the best biomarkers when compared with other biochemical markers to predict adverse maternal (area under the curve, 0.81; 95% confidence interval, 0.72-0.90) and fetal (area under the curve, 0.88; 95% confidence interval, 0.80-0.96) outcomes in preeclampsia.

CONCLUSION

The sFlt-1/PlGF ratio correlates better with adverse maternal and perinatal outcomes than any other biochemical marker in an Indian population. The incorporation of the sFlt-1/PlGF ratio in women with preeclampsia can help in predicting the severity of the condition and the timings of the delivery.

Study on lipid nanomicelles targeting placenta for the treatment of preeclampsia

In view of the serious clinical harm of preeclampsia and the lack of effective treatment methods, a PEG-modified lipid hybrid micelle was designed with folic acid molecule on the surface, containing siRNA, targeted delivery to the placenta, interfering the expression of sFlt-1 and treating preeclampsia. In this paper, the preparation and characterization of lipid hybrid micelles were investigated in detail, the cytology in vitro and in vivo distribution, pharmacodynamics, safety and action mechanism of the preparation were studied, which laid a foundation for gene therapy of preeclampsia.

Placental growth factor for the prognosis of women with preeclampsia (fullPIERS model extension): context matters

Background

The fullPIERS risk prediction model was developed to identify which women admitted with confirmed diagnosis of preeclampsia are at highest risk of developing serious maternal complications. The model discriminates well between women who develop (vs. those who do not) adverse maternal outcomes. It has been externally validated in several populations. We assessed whether placental growth factor (PlGF), a biomarker associated with preeclampsia risk, adds incremental value to the fullPIERS model.

Methods

Using a cohort of women admitted into tertiary hospitals in well-resourced settings (the USA and Canada), between May 2010 to February 2012, we evaluated the incremental value of PlGF added to fullPIERS for prediction of adverse maternal outcomes within 48 h after admission with confirmed preeclampsia. The discriminatory performance of PlGF and the fullPIERS model were assessed in this cohort using the area under the receiver’s operating characteristic curve (AUROC) while the extended model (fullPIERS +PlGF) was assessed based on net reclassification index (NRI) and integrated discrimination improvement (IDI) performances.

Results

In a cohort of 541 women delivered shortly (< 1 week) after presentation, 8.1% experienced an adverse maternal outcome within 48 h of admission. Prediction of adverse maternal outcomes was not improved by addition of PlGF to fullPIERS (NRI: -8.7, IDI − 0.06). Discriminatory performance (AUROC) was 0.67 [95%CI: 0.59–0.75] for fullPIERS only and 0.67 [95%CI: 0.58–0.76]) for fullPIERS extended with PlGF, a performance worse than previously documented in fullPIERS external validation studies (AUROC > 0.75).

Conclusions

While fullPIERS model performance may have been affected by differences in healthcare context between this study cohort and the model development and validation cohorts, future studies are required to confirm whether PlGF adds incremental benefit to the fullPIERS model for prediction of adverse maternal outcomes in preeclampsia in settings where expectant management is practiced.

Values of serum sFlt-1, PLGF levels, and sFlt-1/PLGF ratio in diagnosis and prognosis evaluation of preeclamptic patients

PURPOSE

To explore the values of serum sFlt-1, PLGF levels and sFlt-1/PLGF ratio in the diagnosis and prognosis evaluation of preeclamptic patients.

METHODS

From March 2017 to October 2018, 60 cases of early onset preeclampsia (E-PE), 116 cases of late onset preeclampsia (L-PE) and 50 cases of gestational hypertension (GH) were selected. Fifty women who had vaginal bleeding or abdominal distention before 34 gestational weeks were selected as an early control group, and 50 pregnant women awaiting delivery were selected as a late control group. Serum sFlt-1 and PLGF levels were measured, and changes of sFlt-1/PLGF ratio were analyzed. Their correlations with neonatal birth weight were analyzed, and ROC curves were plotted for E-PE diagnosis.

RESULTS

The sFlt-1/PLGF ratio of patients with E-PE was significantly higher than those of other groups, and negatively correlated with neonatal birth weight. When the ratio was used as a diagnostic index, AUC was 0.975. The ratio of patients with severe L-PE exceeded that of cases with mild L-PE. In all preeclamptic patients, the ratio was elevated with increasing maternal and neonatal complications.

CONCLUSION

sFlt-1/PLGF ratio is valuable for assessing the severity of preeclampsia and diagnosing E-PE, and can be used to predict neonatal birth weight.

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

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

The Role of Placental Growth Factor, Soluble Endoglin, and Uterine Artery Diastolic Notch to Predict the Early Onset of Preeclampsia

BACKGROUND:

Reducing maternal mortality is one of the targets in the Millennium Development Goals (MDGs). In a systematic review, 4.6 per cent (95% CI 2.7-8.2) of pregnancies were complicated by preeclampsia worldwide. Preeclampsia occurs in around 10% of pregnancies in the world whereas developing countries contribute more than developed countries. In developing countries, there are 13 cases of preeclampsia in every 1,000 births, whereas in developed countries only 2-3 cases of preeclampsia are found in every 10,000 deliveries. Variations in prevalence among countries reflect, at least in part, differences in the distribution of maternal age and the proportion of nulliparous pregnant women in the population.

AIM:

We aimed to investigate the role of placental growth factor, soluble endoglin, and uterine artery diastolic notch to predict the early onset of preeclampsia.

METHODS:

This study used an analytical study with a nested case-control design. The study was conducted at Bunda Thamrin Hospital, Tanjung Mulia Mitra Medika Hospital, Sundari Hospital and a private clinic, from March to November 2018 with a total sample of 70 research subjects.

RESULTS:

Uterine artery diastolic notch was not found in 50% of subjects. A total of 27 subjects (38.6%) had a unilateral diastolic notch, and 8 subjects (11.4%) had a bilateral diastolic notch. Cut-off point PIGF levels was 441 pg/ml, and Area Under Curve (AUC) 82.5% (95% CI 61.5%-100%), with sensitivity 80% and specificity 87.7%. The levels sEng in this study could not predict the incidence of early-onset preeclampsia (p = 0.113). Combined PlGF and pulsatile index of uterine arteries may predict early onset preeclampsia with sensitivity 40% and specificity 90.77%. From these results, pregnant women o 22-24 weeks of pregnancy, the levels of PlGF and the uterine artery pulsatility index can be a predictor of early-onset preeclampsia. Examination of PlGF levels alone is sufficient as a predictor of early-onset preeclampsia.

CONCLUSION:

From these results, it can be concluded that in pregnant women of 22-24 weeks, the diastolic notches in uterine arteries cannot predict the incidence of early-onset preeclampsia. PlGF levels and pulsatile index of uterine arteries can be used as predictors of early-onset preeclampsia although examination of PlGF levels alone is sufficient as a predictor of early-onset preeclampsia.

[Potential value of placental angiogenic factors as biomarkers in preeclampsia for clinical physicians]

The role of angiogenic factors in the onset of clinical manifestations of preeclampsia was demonstrated in 2003 by the implication of sFlt-1, PlGF and VEGF, and in 2006 by the implication of soluble endoglin. Placental ischemia and inflammation observed in preeclampsia alter both the production and progression of angiogenic factors during pregnancy. During the first trimester, the combination of PlGF with clinical, biophysical and biological factors results in a better test than the conventional one. However, the clinical value of this method remains to be confirmed. During the second and third trimesters, the sFlt-1/PlGF ratio may be used, with or without pre-existing renal disease, for short-term prediction, diagnosis, and prognosis, and to evaluate the effectiveness of preeclampsia treatment. While a sFlt-1/PlGF ratio<38 and≤33, respectively, rules out the short-term onset and diagnosis of preeclampsia, a sFlt-1/PlGF ratio≥85 between 20 and 34 weeks of pregnancy and≥110 beyond 34 weeks of pregnancy confirms a diagnosis of preeclampsia. Angiogenic and non-angiogenic preeclampsia are identified by a sFlt-1PlGF≥85 and<85, respectively, with the risk of maternal and fetal complications at two weeks differing between the two. Similarly, a sFlt-1/PlGF ratio>665 and>205, respectively, is a good short-term predictor of adverse outcomes of early and late-onset preeclampsia. These values could be incorporated into future guidelines for better clinical management of preeclampsia.

Integrated Systems Biology Approach Identifies Novel Maternal and Placental Pathways of Preeclampsia

Preeclampsia is a disease of the mother, fetus, and placenta, and the gaps in our understanding of the complex interactions among their respective disease pathways preclude successful treatment and prevention. The placenta has a key role in the pathogenesis of the terminal pathway characterized by exaggerated maternal systemic inflammation, generalized endothelial damage, hypertension, and proteinuria. This sine qua non of preeclampsia may be triggered by distinct underlying mechanisms that occur at early stages of pregnancy and induce different phenotypes. To gain insights into these molecular pathways, we employed a systems biology approach and integrated different “omics,” clinical, placental, and functional data from patients with distinct phenotypes of preeclampsia. First trimester maternal blood proteomics uncovered an altered abundance of proteins of the renin-angiotensin and immune systems, complement, and coagulation cascades in patients with term or preterm preeclampsia. Moreover, first trimester maternal blood from preterm preeclamptic patients in vitro dysregulated trophoblastic gene expression. Placental transcriptomics of women with preterm preeclampsia identified distinct gene modules associated with maternal or fetal disease. Placental “virtual” liquid biopsy showed that the dysregulation of these disease gene modules originates during the first trimester. In vitro experiments on hub transcription factors of these gene modules demonstrated that DNA hypermethylation in the regulatory region of ZNF554 leads to gene down-regulation and impaired trophoblast invasion, while BCL6 and ARNT2 up-regulation sensitizes the trophoblast to ischemia, hallmarks of preterm preeclampsia. In summary, our data suggest that there are distinct maternal and placental disease pathways, and their interaction influences the clinical presentation of preeclampsia. The activation of maternal disease pathways can be detected in all phenotypes of preeclampsia earlier and upstream of placental dysfunction, not only downstream as described before, and distinct placental disease pathways are superimposed on these maternal pathways. This is a paradigm shift, which, in agreement with epidemiological studies, warrants for the central pathologic role of preexisting maternal diseases or perturbed maternal–fetal–placental immune interactions in preeclampsia. The description of these novel pathways in the “molecular phase” of preeclampsia and the identification of their hub molecules may enable timely molecular characterization of patients with distinct preeclampsia phenotypes.

Placental growth factor (alone or in combination with soluble fms-like tyrosine kinase 1) as an aid to the assessment of women with suspected pre-eclampsia: systematic review and economic analysis

BACKGROUND

Pre-eclampsia (PE) prediction based on blood pressure, presence of protein in the urine, symptoms and laboratory test abnormalities can result in false-positive diagnoses. This may lead to unnecessary antenatal admissions and preterm delivery. Blood tests that measure placental growth factor (PlGF) or the ratio of soluble fms-like tyrosine kinase 1 (sFlt-1) to PlGF could aid prediction of PE if either were added to routine clinical assessment or used as a replacement for proteinuria testing.

OBJECTIVES

To evaluate the diagnostic accuracy and cost-effectiveness of PlGF-based tests for patients referred to secondary care with suspected PE in weeks 20-37 of pregnancy.

DESIGN

Systematic reviews and an economic analysis.

DATA SOURCES

Bibliographic databases including MEDLINE, EMBASE, Web of Science and The Cochrane Library and Database of Abstracts of Reviews of Effects were searched up to July 2015 for English-language references. Conferences, websites, systematic reviews and confidential company submissions were also accessed.

REVIEW METHODS

Systematic reviews of test accuracy and economic studies were conducted to inform an economic analysis. Test accuracy studies were required to include women with suspected PE and report quantitatively the accuracy of PlGF-based tests; their risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria. The economic studies review had broad eligibility criteria to capture any types of economic analysis; critical appraisal employed standard checklists consistent with National Institute for Health and Care Excellence criteria. Study selection, critical appraisal and data extraction in both reviews were performed by two reviewers.

ECONOMIC ANALYSIS

An independent economic analysis was conducted based on a decision tree model, using the best evidence available. The model evaluates costs (2014, GBP) from a NHS and Personal Social Services perspective. Given the short analysis time horizon, no discounting was undertaken.

RESULTS

Four studies were included in the systematic review of test accuracy: two on Alere's Triage^® PlGF test (Alere, Inc., San Diego, CA, USA) for predicting PE requiring delivery within a specified time and two on Roche Diagnostics' Elecsys^® sFlt-1 to PlGF ratio test (Roche Diagnostics GmbH, Mannheim, Germany) for predicting PE within a specified time. Three studies were included in the systematic review of economic studies, and two confidential company economic analyses were assessed separately. Study heterogeneity precluded meta-analyses of test accuracy or cost-analysis outcomes, so narrative syntheses were conducted to inform the independent economic model. The model predicts that, when supplementing routine clinical assessment for rule-out and rule-in of PE, the two tests would be cost-saving in weeks 20-35 of gestation, and marginally cost-saving in weeks 35-37, but with minuscule impact on quality of life. Length of neonatal intensive care unit stay was the most influential parameter in sensitivity analyses. All other sensitivity analyses had negligible effects on results.

LIMITATIONS

No head-to-head comparisons of the tests were identified. No studies investigated accuracy of PlGF-based tests when used as a replacement for proteinuria testing. Test accuracy studies were found to be at high risk of clinical review bias.

CONCLUSIONS

The Triage and Elecsys tests would save money if added to routine clinical assessment for PE. The magnitude of savings is uncertain, but the tests remain cost-saving under worst-case assumptions. Further research is required to clarify how the test results would be interpreted and applied in clinical practice.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015017670.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The sFlt-1/PlGF ratio as a predictor for poor pregnancy and neonatal outcomes

BACKGROUND

Soluble fms-like tyrosine kinase receptor-1 (sFlt-1)/placental growth factor (PlGF) ratio has been studied extensively as a predictive marker for pre-eclampsia. However, its usefulness for predicting neonatal outcomes remains unknown. This study aimed to evaluate the association of sFlt-1/PlGF ratio with pregnancy outcomes, neonatal morbidities and short-term postnatal growth patterns in pregnant women and their babies.

METHODS

sFlt-1 and PlGF were measured in women with fetal intrauterine growth retardation (IUGR) or pre-eclampsia during gestational age (GA) of 16-36 weeks. These women were classified into high- and low-ratio groups with a sFlt-1/PlGF cut-off ratio of 85. The maternal and neonatal outcomes were retrospectively reviewed and compared between the two groups.

RESULTS

A total of 25 pregnant women were recruited. Thirteen of them had a sFlt-1/PlGF ratio over 85 and twelve had a ratio of less than 85. The median duration from elevation of sFlt-1/PlGF to delivery was 4.5 weeks. Women in the high SFlt-1/PlGF ratio group had higher rates of intrauterine fetal demise (2/13 vs. 0/12) and early termination (1/13 vs. 0/12). The surviving offspring in this group had a higher incidence of preterm birth (GA: 31.4 ± 2.9 weeks vs. 37.3 ± 1.3 weeks, p < 0.001), lower birth weight (1142 ± 472 g vs. 2311 ± 236 g, p < 0.001), higher incidence of respiratory distress syndrome (6/10 vs. 0/12, p = 0.002) and bronchopulmonary dysplasia (4/10 vs. 0/12, p = 0.01). However, the percentile of body weight, height and head circumference at 28 days of age, 56 days of age and the corrected age of 6 months were comparable between groups.

CONCLUSIONS

High sFlt-1/PlGF ratio in pregnant women is associated with poor pregnancy and neonatal outcomes. Therefore, the monitoring of sFlt-1/PlGF ratio in pregnant women with fetal IUGR and timely management for placenta-associated diseases are recommended.

Expression profiling of maternal plasma and placenta microRNAs in preeclamptic pregnancies by microarray technology

Preeclampsia (PE) is one of the leading causes of maternal and fetal morbidity and mortality, occurring usually in the second half of pregnancy and affecting approximately 5-8% of pregnancies in the world. miRNAs play critical role in the regulation of placental development processes. We aimed to determine specific novel miRNAs for early diagnosis of preeclampsia which is one of the most dangerous pregnancy diseases. In this study 72 samples, maternal age 22 ≤ and ≤36, have been analyzed; maternal plasma and placental miRNAs were isolated from 18 severe preeclampsia (sPE) patients and 18 controls, respectively. Profiling of human miRNAs (1368 probe) was performed in samples with Agilent v16 microarrays for detection of the differences in miRNA expression between two groups. The results were validated by using TaqMan RT-qPCR method. The analysis indicated that 406 of these miRNAs in all placentas and 42 of these miRNAs in all maternal plasma were expressed. The relative expression analysis has shown that 12 miRNAs (p < 0.05 and >2-fold) in maternal plasma were differentially expressed in PE and control group. However, five miRNAs were validated by qRT-PCR. Once validated miRNAs have been searched in databases for their target genes and function, it has been shown that there are some preeclampsia related pathways as a target such as angiogenesis, cardiovascular, hypertension, placental abruption and preeclampsia disorders. Differentially expressed and validated plasma miRNAs might be used as notable biomarkers for non-invasive early diagnosis of preeclampsia and treatment of disease.

Serum biomarkers combined with uterine artery Doppler in prediction of preeclampsia

First-trimester screening may be a major advantage over a second-trimester approach since it opens prospects for early and more efficient interventions. The aim of the current study was to evaluate whether the measurement of maternal serum inhibin A, activin A and placental growth factor (PlGF) at three to four months gestation with the second-trimester uterine artery pulsatility index (PI) are useful in predicting preeclampsia in a group of nulliparous women. All the patients also underwent uterine artery Doppler examination to measure the PI at 22–24 weeks gestation. Inhibin A, activin A and PlGF were measured using an ELISA by an examiner who was blinded to the pregnancy outcome. Thirty-eight cases with preeclampsia and 100 controls were analyzed. Second-trimester uterine artery PI and marker levels were expressed as multiples of the median (MoM). The uterine artery PI was increased in pregnancies with preeclampsia compared with controls. In pregnancies that developed preeclampsia, the uterine artery PI was increased (1.61±0.047 vs. 1.02±0.049, P<0.001), as was the level of inhibin A (1.72±0.023 vs. 1.03±0.063, P<0.001) and the level of activin A (1.68±0.38 vs. 1.06±0.42, P<0.001) compared with the controls. In contrast, the level of PlGF was decreased in pregnancies that developed preeclampsia compared with the controls (0.69±0.23 vs. 1.00±0.26, P<0.001). A combination of activin A, PlGF and uterine artery PI gave an AUC of 0.915 (95% CI, 0.812–0.928; P<0.001) with a sensitivity of 91% at a specificity of 82%. In our study, we demonstrated that both serum inhibin A and activin A levels were increased, while the PlGF level was decreased in the early second-trimester in women who developed preeclampsia.

Prediction of preeclampsia and induced delivery at <34 weeks gestation by sFLT-1 and PlGF in patients with abnormal midtrimester uterine Doppler velocimetry: a prospective cohort analysis

Background

Women with bilateral abnormal uterine artery Doppler velocimetry (UtADV) are at increased risk for an adverse pregnancy outcome. This study aimed to determine if additional assessment of midtrimester angiogenic factors improves the predictive accuracy of Doppler results for various outcome parameters.

Methods

Women with a bilateral abnormal UtADV, which was defined as a postsystolic incision and/or an increased pulsatility index greater than the 95^th centile, and a singleton pregnancy were prospectively recruited between 19 + 0 and 26 + 6 weeks of gestation. Maternal serum levels of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFLT-1) were measured with a fully automated immunoassay and their ratio was calculated.

Results

Angiogenic factors could predict the development of preeclampsia (PE), as well as induced delivery at <34 weeks of gestation, but failed to predict the development of normotensive intrauterine growth restriction. Twelve (24.0%) of the 50 recruited women developed PE. Nine of these patients had early-onset disease (<34 + 0 weeks). Six (12.0%) patients were delivered at <34 + 0 weeks. The most useful test results in the prediction of PE and induced delivery at <34 + 0 weeks were observed using the sFLT-1/PlGF >95^th centile ratio with a sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of 66.7%, 89.5%, 66.7%, and 89.5% for PE, and 85.7%, 86.1%, 50.1%, and 97.4% for induced delivery, respectively. Positive and negative likelihood ratios were 6.33 (95% CI 2.31–17.38) and 0.37 (95% CI 0.17–0.84) for PE, and 6.14 (95% CI 2.76–13.69) and 0.17 (0.03–1.02) for induced delivery, respectively. Corresponding odds ratios were 17.0 (95% CI 3.5–83.0) and 37.0 (95% CI 3.8–363.9), respectively.

Conclusions

Measurement of angiogenic factors improves the specificity of an abnormal UtADV for prediction of PE. Compared with prediction of PE an abnormal sFLT-1/PlGF ratio revealed higher sensitivity for prediction of induced delivery at <34 + 0 weeks. The NPV of 97% will help to reassure most patients with an abnormal UtADV and a normal sFLT-1/PlGF ratio.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2393-14-292) contains supplementary material, which is available to authorized users.

Maternal hyperlipidemia and the risk of preeclampsia: a meta-analysis

Published reports examining lipid levels during pregnancy and preeclampsia have been inconsistent. The objective of this meta-analysis was to test the association between preeclampsia and maternal total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), non-HDL-C, and triglyceride levels measured during pregnancy. We conducted a systematic search for studies published between the index date until July 2013 reporting maternal lipid levels in women with preeclampsia and normotensive pregnant women. Seventy-four studies met all eligibility criteria and were included in the meta-analysis. Weighted mean differences in lipid levels were calculated using a random-effects model. Statistical heterogeneity was investigated using the I(2) statistic. Meta-regression was used to identify sources of heterogeneity. Preeclampsia was associated with elevated total cholesterol, non-HDL-C, and triglyceride levels, regardless of gestational age at the time of blood sampling, and with lower levels of HDL-C in the third trimester. A marginal association was found with LDL-C levels. Statistical heterogeneity was detected in all analyses. Meta-regression analyses suggested that differences in body mass index (weight (kg)/height (m)(2)) across studies may be partially responsible for the heterogeneity in the triglyceride and LDL-C analyses. This systematic review and meta-analysis demonstrates that women who develop preeclampsia have elevated levels of total cholesterol, non-HDL-C, and triglycerides during all trimesters of pregnancy, as well as lower levels of HDL-C during the third trimester.