Haemostatic, fibrinolytic and endothelial variables in normal pregnancies and pre-eclampsia

Increased contact activated endogenous thrombin potential in pregnant women with preeclampsia

Preeclampsia is a worldwide contributor to maternal and fetal morbidity and mortality. Women with preeclampsia are in a hyper-coagulable state with increased risk of thromboembolic disease later in life compared with normal pregnant women. The contact system (CAS) in plasma can mediate thrombin generation and is an important contributor to thrombus growth, but the activation of CAS during pregnancy complicated by preeclampsia is not yet elucidated, and CAS may play a role in the pathophysiology of preeclampsia. Therefore, the aim of the study is to address thrombin generation, and in particular, the capacity of the CAS-mediated pathway in patients with preeclampsia compared with pregnant controls. One hundred and seventeen women with preeclampsia and matched controls were included. The project was registered at www.clinicaltrials.gov as NCT04825145. CAS and tissue factor induced thrombin generation, proteins C and S, antithrombin, and histidine-rich glycoprotein (HRG) were assessed. Women with preeclampsia had significantly increased CAS and tissue factor-induced endogenous thrombin potential (ETP), and HRG compared with controls, P  = 0.022, P  = 0.024, and P  = 0.02, respectively. The concentrations of protein C and antithrombin were significantly reduced in the preeclampsia group, P  = 0.024 and P  < 0.0001, respectively. No significant difference in the concentration of protein S was detected, P  = 0.06. This study demonstrates a significant increased CAS-induced ETP and an overall decrease of important regulators of coagulation in women with preeclampsia compared with controls. These aspects can contribute to the hyper-coagulable state characterizing preeclampsia.

Plasminogen activator inhibitor-2 and impaired fibrinolysis in pregnancy and sickle cell anemia

PURPOSE

This is the first study that aimed to determine antigen levels in plasma and genotypes of PAI-2 in pregnant and non-pregnant homozygous sickle cell anemia (SCA) patients.

METHODS

The study subjects were all Bahraini females in the reproductive age group. The study population included 31 pregnant homozygous SS (SCA) patients. Three control groups were also studied to evaluate the effect of pregnancy and SCA on PAI-2 levels and fibrinolysis: (1) 31 healthy non-pregnant volunteers; (2) 31 cases of normal pregnancy; and (3) 20 non-pregnant SCA patients. Pregnancies were screened in the second (TM2) and third (TM3) trimesters. Global coagulation, fibrinolysis rate (euglobulin clot lysis time, ECLT), PAI-2 antigen (ELISA), and PAI-2 Ser(413)/Cys polymorphism (restriction fragment length polymorphism analysis) were determined.

RESULTS

Feto-maternal complications were documented in both pregnancy groups. PAI-2 antigen levels were undetectable in the non-pregnant groups, but was quantifiable in both pregnant groups. Impaired fibrinolysis rate and rising PAI-2 levels with progression of pregnancy were observed in both healthy and SCA subjects. These changes were more prominent in SCA, although the rise in ECLT was less steep and PAI-2 antigen levels were not significantly different compared to normal pregnancy in the third trimester. No correlation was observed between PAI-2 genotypes and plasma antigen levels. Also, no significant difference in feto-maternal complications was found in normal (n = 25) versus SCA pregnant patients (n = 30).

CONCLUSIONS

These observations suggest that with progression of pregnancy, increasing PAI-2 levels contribute to the hypercoagulable state, particularly in SCA patients.

A Retrospective Case-Control Study on the Diagnostic Values of Hemostatic Markers in Hypertensive Disorder of Pregnancy

Objective

The purpose of this study was to evaluate the diagnostic performance of the following hemostatic markers in hypertensive disorder of pregnancy (HDP): tissue-type plasminogen activator and inhibitor-1 complex (tPAI-C), thrombomodulin, thrombin-antithrombin complex, plasmin inhibitor-plasmin complex, D-dimer, and fibrinogen degradation products.

Methods

A total of 311 individuals diagnosed with HDP and 187 healthy controls (HC) of matched gestational age were admitted, including 175 subjects with gestational hypertension, 94 with mild preeclampsia, and 42 with severe preeclampsia.

Results

Compared with those of the HC group, the plasma concentrations of all the hemostatic markers continuously increased with the clinical severity of the hypertensive disorder, regardless of their statistical significance. In the receiver operating characteristic analysis, tPAI-C displayed the best discrimination performance.

Conclusion

The tPAI-C level was consistently and significantly elevated across the different HDP groups when compared with the HC group, suggesting aggravated fibrinolysis disorder increasing with the severity of the HDP.

Fibrinolytic Changes in Women with Preeclampsia

Objectives

Preeclampsia (PE) is a serious complication of pregnancy. The fibrinolytic system play crucial roles regarding placentation and evolution of PE.

Aim

To study comprehensively components of the fibrinolytic system and fibrin lysability in women with PE.

Design and Methods

117 women with PE and matched controls were included. Tissue type plasminogen activator (t-PA), plasminogen, PAI-1, plasmin inhibitor (PI), D-dimer, the fibrinolytic potential of dextran sulphate euglobulin fraction (DEF), PAI-2, polymere PAI-2, fibrin clot lysability, thrombin activatable fibrinolysis inhibitor (TAFI) and fibrinogen were assessed.

Results

Women with PE had significantly increased concentrations of t-PA and PAI-1, whereas the plasma concentration of PAI-2 was significantly lower compared to controls, p < 0.0001. Polymere PAI-2 was detected in both groups. DEF, TAFI and fibrinogen were not different between the groups. D-dimer was significantly increased and plasminogen/PI together with fibrin clot lysability time decreased in the PE-group, p  =  0.0004 p  =  0.04, p  =  0.03, p < 0.0001 respectively.

Conclusion

This study demonstrates that PE is associated with an affected t-PA/PAI-1 system, decreased PAI-2 and increased fibrin lysability. Furthermore, PAI-2 has the potential to polymerize during pregnancy.

Immature Platelet Fraction and Thrombin Generation: Preeclampsia Biomarkers

Preeclampsia, a human pregnancy syndrome, is characterized by elevated blood pressure and proteinuria after the 20th week of gestation. Its etiology remains unknown, and its pathophysiological mechanisms are related to placental hypoperfusion, endothelial dysfunction, inflammation, and coagulation cascade activation. Recently, the role of the complement system has been considered. This syndrome is one of the main causes of maternal and fetal mortality and morbidity. This article discusses the hypothesis of preeclampsia being triggered by the occurrence of inadequate implantation of the syncytiotrophoblast, associated with bleeding during the first stage of pregnancy and with augmented thrombin generation. Thrombin activates platelets, increasing the release of antiangiogenic factors and activating the complement system, inducing the membrane attack complex (C5b9). Immature platelet fraction and thrombin generation may be possible blood biomarkers to help the early diagnosis of preeclampsia.

Pregnant biglycan knockout mice have altered cardiorenal adaptations and a shorter gestational length, but do not develop a pre-eclamptic phenotype

INTRODUCTION

Pre-eclampsia complicates 4.6% of pregnancies and is linked to impaired placentation; likely due to dysregulated vasculogenesis/angiogenesis. Proteoglycans, such as biglycan, are located on the endothelial surface of fetal capillaries. Biglycan is reduced in the placenta of pregnancies complicated by fetal growth restriction and pre-eclampsia. Importantly, biglycan stimulates angiogenesis in numerous tissues. Therefore, this study investigated whether biglycan knockdown in mice results in a pre-eclamptic phenotype.

METHODS

Wild-type (WT) and Bgn-/- mice underwent cardiorenal measurements prior to and during pregnancy. One cohort of mice underwent post-mortem on gestational day 18 (E18) and another cohort underwent post-mortem on postnatal day 1 (PN1), with maternal and offspring tissues of relevance collected.

RESULTS

Bgn-/- dams had increased heart rate (+9%, p < 0.037) and reduced systolic (-11%, p < 0.001), diastolic (-15%, p < 0.001), and mean arterial (-12%, p < 0.001) pressures at all ages investigated compared to WT. Additionally, Bgn-/- dams had reduced urine flow rate (-64%, p < 0.001) as well as reduced urinary excretions (-49%, p < 0.004) during late gestation compared to WT. Bgn-/- pups had higher body weight (+8%, p = 0.004; E18 only) and a higher liver-to-brain weight ratio (+43%, p < 0.001). Placental weight was unaltered with only minor changes in vasculogenic and angiogenic gene abundances detected, which did not correlate to changes in protein expression.

DISCUSSION

This study demonstrated that total knockdown of biglycan is not associated with features of pre-eclampsia.

Predictive values of various serum biomarkers in women with suspected preeclampsia: A prospective study

BACKGROUND

Preeclampsia (PE) prediction has been shown to improve the maternal and fetal outcomes in pregnancy. We aimed to evaluate the PE prediction values of a series of serum biomarkers.

METHODS

The singleton pregnant women (20-36 gestational weeks) with PE-related clinical and/or laboratory presentations were recruited and had the blood drawn at their first visits. The following markers were tested with the collected serum samples: soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PlGF), thrombomodulin (TM), tissue plasminogen activator inhibitor complex (tPAI-C), complement factors C1q, B, H, glycosylated fibronectin (GlyFn), pregnancy-associated plasma protein-A2 (PAPP-A2), blood urea nitrogen (BUN), creatinine (Cre), uric acid (UA), and cystatin C (Cysc).

RESULTS

Of the 196 recruited subjects, 25% (n = 49) developed preeclampsia before delivery, and 75% remained preeclampsia negative (n = 147). The serum levels of sFlt-1, BUN, Cre, UA, Cysc, and PAPP-A2 were significantly elevated, and the PlGF level was significantly decreased in the preeclampsia-positive patients. In the receiver operating characteristics (ROC) analyses, the area under the curves were listed in the order of decreasing values: 0.73 (UA), 0.67 (sFlt-1/PlGF), 0.66 (Cysc), 0.65 (GlyFn/PlGF), 0.64 (PAPP-A2/PlGF), 0.63 (BUN), 0.63 (Cre), and 0.60 (PAPP-A2). The positive predictive values of these serum markers were between 33.1% and 58.5%, and the negative predictive values were between 80.9% and 89.5%.

CONCLUSIONS

The serum markers investigated in current study showed better performance in ruling out than ruling in PE. Absence of pre-defined latency period between blood draw and the onset of PE limits the clinical utility of these markers.

Changes in laboratory markers of thrombotic risk early in the first trimester of pregnancy may be linked to an increase in estradiol and progesterone

BACKGROUND

Pregnant women are at increased risk of venous thrombosis compared to non-pregnant women. Epidemiological and laboratory data suggest that hypercoagulability begins in the first trimester but it is unknown exactly how early in pregnancy this develops. The mechanisms that result in a prothrombotic state may involve oestrogens and progestogens.

METHODS

Plasma samples were taken prior to conception and five times in early pregnancy, up to Day 59 gestation, from 22 women undergoing natural cycle in vitro fertilization, who subsequently gave birth at term following a normal pregnancy. Thrombin generation, free Protein S, Ddimer, Fibrinogen, factor VIII, estradiol and progesterone were measured. To counter inter-individual variability, the change in laboratory measurements between the pre-pregnant and pregnant state were measured over time.

RESULTS

Peak thrombin, Endogenous Thrombin Potential, Velocity Index and fibrinogen significantly increased, and free Protein S significantly decreased, from pre-pregnancy levels, by 32 days gestation. Ddimer and VIII significantly increased from pre-pregnancy levels by 59 days gestation. Estradiol significantly increased by Day 32 gestation with a non-significant increase of 67% by Day 24 gestation. Progesterone significantly increased by Day 32 gestation. Almost all laboratory markers of thrombosis correlated significantly with estradiol and progesterone.

CONCLUSION

Our work is the first to demonstrate that the prothrombotic state develops very early in the first trimester. Laboratory markers of hypercoagulability correlate significantly with estradiol and progesterone suggesting these are linked to the prothrombotic state of pregnancy. Clinicians should consider commencing thromboprophylaxis early in the first trimester in women at high thrombotic risk.

Longitudinal assessment of D-dimer and plasminogen activator inhibitor type-1 plasma levels in pregnant women with risk factors for preeclampsia

OBJECTIVE

Investigating D-Dimer/D-Di and plasminogen activator inhibitor type-1/PAI-1 levels throughout gestation in women with preeclampsia/PE risk factors.

METHODS

D-Di and PAI-1 plasma levels were determined in 28 women at 12-19, 20-29, 30-34 and 35-40 weeks of gestation.

RESULTS

D-Di was lower at 12-19 weeks and higher at 30-34 weeks in women who developed PE versus who did not develop it. D-Di increased throughout gestation in both groups, peaking earlier in pregnant women who developed PE versus who did not develop it. PA1-1 increased across gestation, but it didn't differ between groups.

CONCLUSION

D-Di was able to discriminate these groups of women at 12-19 and 30-34 weeks of gestation.

Effects of gestational hypertension and pre-eclampsia in mRNA expression of fibrinolysis genes in primary cultured human umbilical vein endothelial cells

Hypertension disorders (HD) and pre-eclampsia (PRE) are leading causes of maternal deaths worldwide. PRE is associated with vascular endothelial dysfunction and with deregulation of the fibrinolysis pathway genes. Fibrinolysis is the fibrin clot hydrolysis process catalyzed by plasmin, a proteolytic enzyme formed from plasminogen. Plasminogen is cleaved by tissue-type (tPA) and urokinase-type (uPA) activators and inhibited by the plasminogen activator inhibitors type-1 (PAI-1) and type-2 (PAI-2). The whole process maintains blood hemostasis. This study aims to assess PAI-1, PAI-2, tPA and uPA mRNA expression in primary cultured human umbilical vein endothelial cells (HUVEC) isolated and cultured from healthy, HD and PRE women. Results show that PAI-1 and PAI-2 mRNA decreased in HD-HUVEC, whereas PAI-1 and uPA decreased in PRE-HUVEC cultures compared to control ones. Notably, the expression ratio between pro- and anti-fibrinolytic actors remained unchanged among the studied groups. It seems that newborn's hemostasis is maintained balanced probably by a compensatory mechanism that involves changes in the fibrinolysis gene expression profile. The real impact of these changes in mRNA expression is unknown, however, it is suggested that these changes could be associated with an increased predisposition to vascular disease development in the progeny.

Impact of haemostatic mechanisms on pathophysiology of preeclampsia

Preeclampsia (PE) is disorder of new onset hypertension and proteinuria during the second half of pregnancy. There is increasing evidence to implicate placental over-expression of tissue factor and PAR-1 in the pathophysiology of PE. Excessive activation of platelets, neutrophils and the complement system may also contribute to the placental pathology and maternal endothelial responsible for the symptoms of PE. Increased knowledge in this field may identify new therapeutic strategies for the treatment of PE.

Maternal cardiac function at 35-37 weeks' gestation: prediction of pre-eclampsia and gestational hypertension

OBJECTIVE

To investigate the potential value of combining maternal factors with multiples of the normal median values of maternal cardiovascular parameters at 35-37 weeks' gestation in the prediction of pre-eclampsia (PE) and gestational hypertension (GH).

METHODS

In 2764 singleton pregnancies maternal characteristics and medical history were recorded; uterine artery pulsatility index (UtA-PI), mean arterial pressure (MAP) and maternal cardiovascular parameters were measured. Multivariable logistic regression analysis was then used to determine if the maternal factors and maternal cardiovascular parameters made a significant contribution to predicting PE and GH. The performance of screening was determined by the area under receiver-operating characteristics curves.

RESULTS

In pregnancies that subsequently delivered with PE or GH, total peripheral resistance and MAP were higher and maternal cardiac output was lower, mainly owing to a decrease in heart rate in PE and a decrease in stroke volume in GH. The increases in total peripheral resistance and MAP were inversely related to gestational age at delivery. The performance of screening for PE and GH achieved by maternal characteristics and medical history was improved by the inclusion of MAP, but not by UtA-PI or maternal cardiovascular parameters.

CONCLUSIONS

In women developing term PE total peripheral resistance and MAP are increased and maternal cardiac output is reduced. However, assessment of maternal cardiac function at 35-37 weeks' gestation is unlikely to improve the performance of screening for PE provided by maternal factors and MAP alone. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Novel Electrocardiographic Patterns for the Prediction of Hypertensive Disorders of Pregnancy--From Pathophysiology to Practical Implications

Hypertensive disorders of pregnancy are a major cause of poor outcome, including placental abruption, organ failure, cerebrovascular accident and disseminated intravascular coagulation. These disorders are associated with increased fetal risk of intrauterine growth restriction, intrauterine death and prematurity. Electrocardiography (ECG) recently emerged as a useful tool to evaluate cardiovascular complications during pregnancy. Specifically, left atrial abnormalities detected by standard ECG are associated with a fourfold increased risk of developing hypertensive disorders during pregnancy. The mechanisms linking left atrial abnormality on ECG with hypertensive disorders are still elusive. Several mechanisms, possibly reflected by abnormal left atrial activation on ECG, has been suggested. These include increased reactivity to angiotensin II and up-regulation of angiotensin type 1 receptors, with activation of autoantibodies targeting these receptors.

Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy

OBJECTIVE

This guideline summarizes the quality of the evidence to date and provides a reasonable approach to the diagnosis, evaluation and treatment of the hypertensive disorders of pregnancy (HDP).

EVIDENCE

The literature reviewed included the previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines from 2008 and their reference lists, and an update from 2006. Medline, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Registry of Controlled Trials (CCRCT) and Database of Abstracts and Reviews of Effects (DARE) were searched for literature published between January 2006 and March 2012. Articles were restricted to those published in French or English. Recommendations were evaluated using the criteria of the Canadian Task Force on Preventive Health Care and GRADE.

Significance of the platelet distribution width as a severity marker for the development of preeclampsia

OBJECTIVE

To evaluate the platelet distribution width (PDW) and other platelet indices as potential severity markers of preeclampsia (PE).

STUDY DESIGN

A total of 935 pregnant women who had received continuous prenatal care and had undergone delivery were included. The participants were classified into 3 groups: healthy pregnant women (n=816), pregnant women with mild PE (n=59), and pregnant women with severe PE (n=60). Blood samples were collected during antenatal care or at the time of admission, and the platelet indices were compared among the three groups.

RESULTS

Among the three groups, the platelet count and plateletcrit decreased as the disease progressed. The mean platelet volume and the PDW, however, increased as the disease progressed. When compared to the levels of other platelet indices, the PDW showed significant elevation in the severe PE group. In the mild and severe PE groups, the PDW was statistically correlated with the mean arterial pressure (MAP) (r=0.231, p<0.05), whereas other platelet indices were not. In the receiver operating characteristics curve analysis, the area under the curve of the PDW to predict severe PE was 0.74.

CONCLUSIONS

Among platelet indices, the PDW is significantly higher in women with severe PE than in women with mild PE, and is positively correlated with the MAP. Therefore, the PDW can serve as a candidate marker for predicting the severity of PE.

THE EVIDENCE FOR LATE-ONSET PRE-ECLAMPSIA AS A MATERNOGENIC DISEASE OF PREGNANCY

It is our opinion that the evidence from epidemiological observations, clinical trials and biological studies is strong enough to support the view of different origin and phenotypes of pre-eclampsia: placental, which usually occurs (but not exclusively) early in pregnancy and is associated with poor early placentation of different severity with subsequent restriction of foetal growth, at different stages of gestation; and maternogenic, which generally occurs late in pregnancy and it is not related to placental insufficiency and foetal growth restriction.

DNA methylation is altered in maternal blood vessels of women with preeclampsia

We analyzed 27,578 CpG sites that map to 14,495 genes in omental arteries of normal pregnant and preeclamptic women for DNA methylation status using the Illumina platform. We found 1685 genes with a significant difference in DNA methylation at a false discovery rate of <10% with many inflammatory genes having reduced methylation. Unsupervised hierarchical clustering revealed natural clustering by diagnosis and methylation status. Of the genes with significant methylation differences, 236 were significant at a false discovery rate of <5%. When data were analyzed more stringently to a false discovery rate of <5% and difference in methylation of >0.10, 65 genes were identified, all of which showed reduced methylation in preeclampsia. When these genes were mapped to gene ontology for molecular functions and biological processes, 75 molecular functions and 149 biological processes were overrepresented in the preeclamptic vessels. These included smooth muscle contraction, thrombosis, inflammation, redox homeostasis, sugar metabolism, and amino acid metabolism. We speculate that reduced methylation may contribute to the pathogenesis of preeclampsia and that alterations in DNA methylation resulting from preeclampsia may increase maternal risk of cardiovascular disease later in life.

Pregnancy and renal outcomes in lupus nephritis: an update and guide to management

Systemic lupus erythematosis (SLE) commonly affects women of child bearing-age, and advances in treatment have resulted in an increasing number of women with renal involvement becoming pregnant. Knowledge of the relationship of the condition with respect to fertility and pregnancy is important for all clinicians involved in the care of women with lupus nephritis because they have complicated pregnancies. Presentation of lupus nephritis can range from mild asymptomatic proteinuria to rapidly progressive renal failure and may occur before, during, or after pregnancy. The timing of diagnosis may influence pregnancy outcome. Pregnancy may also affect the course of lupus nephritis. All pregnancies in women with lupus nephritis should be planned, preferably after more than six-months of quiescent disease. Predictors of poor obstetric outcome include active disease at conception or early pregnancy, baseline poor renal function with Creatinine >100 μmol/L, proteinuria >0.5 g/24 hours, presence of concurrent antiphospholipid syndrome and hypertension. In this review the most recent studies of pregnancies in women with lupus nephritis are discussed and a practical approach to managing women prepregnancy, during pregnancy and post-partum is described.

Coagulation and Fibrinolytic System Protein Profiles in Women with Normal Pregnancies and Pregnancies Complicated by Hypertension

OBJECTIVE: The current study longitudinally evaluated concentrations of fibrinogen (Fib), D-Dimer, plasminogen activator type-1 (PAI-1) and tissue type plasminogen activator (T-Pa) before pregnancy and in the first and third trimesters of pregnancy with a focus on the pregnancy transition. STUDY DESIGN: Twenty healthy, nonsmoking, nulliparous women, aged 29.8 ± 3.0 years, BMI 23.3 ± 3.2 kg/m(2) were studied during menstrual cycle day 8 ± 4 and again in early (11 - 15 wks) and late (31 - 34 wks) pregnancy. Seventeen women had singleton conceptions and delivered at term with uncomplicated pregnancies (CTL) and three women developed complicated hypertension (CH) during pregnancy after the third trimester (late pregnancy) evaluation. Data are means ± SEM, Significance was based on p < 0.05. RESULTS: Fib was the only protein evaluated that increased in early pregnancy relative to the prepregnancy assessment. D-dimer, PAI-1 and T-Pa increased in the third trimester compared with prepregnant and early pregnant values (p < .001). T-PA was significantly higher during late pregnancy in CH subjects compared with CTL (8.1 ± 0.7 ng/ml vs. 5.0 ± 0.2 ng/ml, p = .02). There were no other differences between groups. CONCLUSIONS: Increases in fibrinogen are evident in early pregnancy whereas fibrinolysis, perhaps in response to the procoagulant environment of pregnancy, is increased during late pregnancy. Before development of clinically overt hypertension, T-Pa is increased without concomitant changes in other proteins assessed. This is consistent with altered endothelial function with preeclampsia that may contribute to, or reflect, the vasculopathy accompanying this disorder.

Predictive Value of Platelet Indices in Development of Preeclampsia

Aim

To evaluate the association between changes in platelet indices (platelet count, mean platelet volume, platelet distribution width) and development of preeclampsia.

Materials and methods

Two hundred pregnant women at 20 to 24 weeks of gestation with singleton pregnancy and normal blood pressure were enrolled after taking well-informed consent. At monthly intervals CBC (complete blood count) was done from 20 to 24 weeks till 40 weeks and 7 days after delivery. Data regarding changes in platelet indices with increasing gestation was collected and analyzed.

Results

Platelet count decreased significantly in patients with preeclampsia compared to normal pregnant patients (19.4% vs 7.4%). Mean platelet volume increased significantly in preeclampsia patients (44.5% vs 9.22%). Increase in PDW was observed significantly in patients with preeclampsia (47.19% vs 29.4%).

Conclusion

Patients with preeclampsia are more likely to have significant decrease in platelet count, increase in PDW and MPV. These changes can be observed at an earlier gestational age than significant rise in BP can be observed and are directly proportional to progressive rise in hypertension. Thus, estimation of platelet indices can be considered as an early, simple and cost-effective procedure in the assessment of severity of preeclampsia.

How to cite this article

Dadhich S, Agrawal S, Soni M, Choudhary R, Jain R, Sharma S, Saini SL. Predictive Value of Platelet Indices in Development of Preeclampsia. J South Asian Feder Obst Gynae 2012;4(1):17-21.

Syncytiotrophoblast microvesicles released from pre-eclampsia placentae exhibit increased tissue factor activity

Background

Pre-eclampsia is a complication of pregnancy associated with activation of coagulation. It is caused by the placenta, which sheds increased amounts of syncytiotrophoblast microvesicles (STBM) into the maternal circulation. We hypothesized that STBM could contribute to the haemostatic activation observed in pre-eclampsia.

Methodology/Principal Findings

STBM were collected by perfusion of the maternal side of placentae from healthy pregnant women and women with pre-eclampsia at caesarean section. Calibrated automated thrombography was used to assess thrombin generation triggered by STBM-borne tissue factor in platelet poor plasma (PPP). No thrombin was detected in PPP alone but the addition of STBM initiated thrombin generation in 14/16 cases. Pre-eclampsia STBM significantly shortened the lag time (LagT, P = 0.01) and time to peak thrombin generation (TTP, P = 0.005) when compared to normal STBM. Blockade of tissue factor eliminated thrombin generation, while inhibition of tissue factor pathway inhibitor significantly shortened LagT (p = 0.01) and TTP (P<0.0001), with a concomitant increase in endogenous thrombin potential.

Conclusions/Significance

STBM triggered thrombin generation in normal plasma in a tissue factor dependent manner, indicating that TF activity is expressed by STBM. This is more pronounced in STBM shed from pre-eclampsia placentae. As more STBM are shed in pre-eclampsia these observations give insight into the disordered haemostasis observed in this condition.

Preeclampsia: pathophysiology and implications for care

Nurses are increasingly encountering pregnant/postpartum women with hypertensive disorders of pregnancy, of which preeclampsia is one of the most common. The Joint Commission published a Sentinel Event Alert in 2010 on prevention of maternal death. This report notes that one of the 5 leading causes of pregnancy-related mortality between 1991 and 1997 was "hypertensive disorder." Preeclampsia presents significant risk to the health of the mother and the fetus. Clearly, nurses must understand the pathophysiology, assessment, management, recurrence risk, and long-term implications of preeclampsia to participate fully in a management plan that promotes safe patient care.

Performance of messenger RNAs circulating in maternal blood in the prediction of preeclampsia at 10-14 weeks

OBJECTIVE

The purpose of this study was to determine whether the combined distribution of a panel of cellular messenger RNA markers can detect preeclampsia long before onset.

STUDY DESIGN

We compared blood at 10-14 weeks from 11 women who ultimately experienced preeclampsia with 88 matched control subjects. After multiples of the median conversion of all the markers, logistic regression was used to calculate the risk of the development of preeclampsia.

RESULTS

Higher multiples of the median values than expected were found for endoglin, fms-related tyrosine kinase 1, and transforming growth factor-β1. Lower multiples of the median values were found for placental growth factor and placental protein 13. Endoglin fms-related tyrosine kinase 1 and transforming growth factor-β1 had the best discriminant power. Messenger RNA species provided independent contributions to the prediction of preeclampsia. In fact, 11 women with preeclampsia scored a median risk of 50% of experiencing preeclampsia. Control subjects scored a median risk of preeclampsia of 0.18%. The detection rate at a 5% false positive rate was 72.3%.

CONCLUSION

The messenger RNA dosage in maternal blood would be a useful method for the calculation of the risk of the development of preeclampsia.

Evidence of the escape of antithrombin from the blood into the interstitial space in pregnant women

OBJECTIVE

we investigated whether ascites samples obtained from pregnant women during cesarean sections contained antithrombin because it is unknown whether antithrombin escapes from the blood and passes into the interstitial space during pregnancy.

METHODS

the concentration and activity levels of antithrombin were determined in six ascites samples obtained from six consecutive women who exhibited generalized edema, ascites, and a gradual decline in antithrombin activity.

RESULTS

all six ascites samples contained antithrombin (mean ± SD, 4.9 ± 2.2 mg/dL; range, 2.7-8.8 mg/dL) and exhibited an antithrombin activity level of 15.5 ± 6.0% (range, 10-24%).

CONCLUSIONS

antithrombin escapes from the blood into the interstitial space in pregnant women. This phenomenon partially explains the gradual decline in antithrombin activity observed in these six pregnant women with generalized edema and large volumes of ascites.

Leukocytes of pregnant women with small-for-gestational age neonates have a different phenotypic and metabolic activity from those of women with preeclampsia

OBJECTIVE

Preeclampsia and pregnancies complicated by small-for-gestational age (SGA) neonates share several underlying mechanisms of disease. However, while an exaggerated systemic maternal inflammatory response is regarded as one of the hallmarks of the pathogenesis of preeclampsia, the presence of a similar systemic intra-vascular inflammation in mothers of SGA neonates without hypertension is controversial. The aim of this study was to determine phenotypic and metabolic changes in granulocytes and monocytes of women who develop preeclampsia and those who deliver an SGA neonate, compared to normal pregnant women.

METHODS

This cross-sectional study included patients with a normal pregnancy (n = 33), preeclampsia (n = 33), and an SGA without preeclampsia (n = 33), matched for gestational age at blood sample collection. Granulocyte and monocyte phenotypes were determined by flow cytometry, using monoclonal antibodies against selective cluster of differentiation (CD) antigens. The panel of antibodies included the following: CD11b, CD14, CD16, CD18, CD49d, CD62L, CD64, CD66b, and HLA-DR. Intracellular reactive oxygen species (iROS) were assessed at the basal state and after stimulation (oxidative burst). Results were reported as mean channel brightness (MCB) or intensity of detected fluorescence. Analysis was conducted with non-parametric statistics. A p-value < 0.01 was considered statistically significant.

RESULTS

(1) Women who delivered an SGA neonate had a higher MCB of CD11b in granulocytes and monocytes than those with a normal pregnancy (p < 0.001 for both); (2) patients with preeclampsia had a lower median MCB of CD62L in granulocytes (p = 0.006) and a higher median basal iROS and oxidative burst in monocytes than women with an SGA neonate (p = 0.003 and p = 0.002, respectively).

CONCLUSION

Pregnancies complicated by the delivery of an SGA neonate are characterized by a higher activation of maternal peripheral leukocytes than in normal pregnancies, but lower than in pregnancies complicated by preeclampsia.

Natural coagulation inhibitors and active protein c resistance in preeclampsia

INTRODUCTION

The etiology of preeclampsia is not fully established. A few studies have shown a relationship between natural coagulation inhibitors and preeclampsia.

OBJECTIVES

The purpose of this study was to investigate the status of natural coagulation inhibitors and active protein C resistance (APC-R) in preeclampsia.

PATIENTS AND METHODS

We studied 70 women with preeclampsia recruited consecutively and 70 healthy pregnant and 70 nonpregnant women as controls. Plasma protein C (PC), free protein S (fPS), antithrombin III (ATIII) and APC-R were evaluated.

RESULTS

ATIII values were found to be significantly lower in preeclamptic patients than in the control groups (p< 0.001). Nevertheless, there was no significant difference between the healthy pregnant and nonpregnant women groups (p=0.141). The fPS values of the preeclamptic and healthy pregnant groups were lower than that of the nonpregnant group (p< 0.001), and the fPS value of the preeclamptic pregnant women was lower than that of healthy pregnant women (p<0.001). The PC value of the preeclamptic pregnant women was lower than that of the control groups (p< 0.001). The PC value of the healthy pregnant women was lower than that of the nonpregnant women (p< 0.001). The mean APC activity values were lower in the preeclamptic patients than that of the control groups (p< 0.001, p< 0.001). The APC-R positivity rates of the preeclamptic groups were higher than that of the control groups (p<0.001).

CONCLUSIONS

This study demonstrated that ATIII, fPS, PC values and APC resistance were lower and APC-R positivity was higher in preeclamptic women than in normal pregnant and nonpregnant women.

Evidence of increased oxidative stress and a change in the plasminogen activator inhibitor (PAI)-1 to PAI-2 ratio in early-onset but not late-onset preeclampsia

OBJECTIVE

The aims of this study were to measure the degree of oxidative stress and alterations in plasminogen activator inhibitor (PAI) type 1 and PAI-2 ratio in women with early-onset and late-onset preeclampsia.

STUDY DESIGN

A case-control study was conducted in women with early-onset (24-32 weeks' gestation; n=18) and late-onset (35-42 weeks' gestation; n=20) preeclampsia and in control pregnant women at corresponding gestational weeks. Placenta, urine, and serum samples were collected.

RESULTS

In early-onset preeclampsia, the median placental concentration of 8-iso-prostaglandin (PG)-F2alpha was higher and the PAI-1 to PAI-2 ratio higher than in early controls. These values did not differ between women with late-onset preeclampsia and their corresponding controls. Serum concentrations of 8-iso-PGF2alpha and vitamins C and E did not differ between cases and controls.

CONCLUSION

Early-onset but not late-onset preeclampsia is associated with increased placental oxidative stress and increased PAI-1 to PAI-2 ratio.

Pregnancy outcome and fibrinolytic, endothelial and coagulation markers in women undergoing uterine artery Doppler screening at 23 weeks

BACKGROUND

Pre-eclampsia (PET) and/or fetal growth restriction (FGR) remain a major cause of maternal and fetal morbidity and mortality. In pregnancy, fibrinolysis is controlled by the maternal endothelium and placenta, both of which are central to the pathogenesis of PET/FGR. Clinically, uterine artery Doppler screening at 23 weeks is used to predict PET/FGR. An abnormal uterine artery Doppler finding is defined as early diastolic bilateral uterine artery notching (BN) in the waveform. However, about 50% of mothers with BN do not develop PET/FGR.

OBJECTIVES

We investigated fibrinolytic changes and uterine artery Doppler findings in the second trimester, and related them to pregnancy outcome; in particular assessing whether fibrinolytic markers could discriminate between normal and abnormal outcome in mothers with BN.

PATIENTS/METHODS

Plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), plasminogen activator inhibitor-2 (PAI-2), plasmin-alpha(2) antiplasmin (PAP), D-dimers and markers of endothelial dysfunction were measured with Doppler ultrasound at 23 weeks.

RESULTS

Those with BN had decreased PAP and D-dimer levels, and raised PAI-1 and thrombomodulin levels. Mothers with BN and PET/FGR had significantly increased t-PA levels and reduced PAI-2 levels.

CONCLUSIONS

BN at 23 weeks of gestation is associated with increased PAI-1 levels. Within the BN group, mothers who developed PET/FGR had increased t-PA levels and decreased PAI-2 levels, although there was no net change in fibrinolysis as measured by D-dimer levels. No single fibrinolytic marker is helpful in determining pregnancy outcome in those with BN, but t-PA and PAI-2 are worthy of study in a multifactorial algorithm.

Disseminated intravascular coagulation in obstetric disorders and its acute haematological management

As activation of the coagulation pathway is a physiological response to injury, the development of disseminated intravascular coagulation (DIC) is a warning signal to the clinician that the primary pathological disease state is decompensating. In pregnancy, DIC can occur in several settings, which include emergencies such as placental abruption and amniotic fluid embolism as well as complications such as pre-eclampsia. Whilst the acuteness of the event and the proportionality in the coagulant and fibrinolytic responses may vary between these different conditions, a common theme for pregnancy-associated DIC is the pivotal role played by the placenta. Removal of the placenta is the linchpin to treatment in most cases but appropriate blood product support is also key to management. This is necessary because DIC itself can have pathological consequences that translate clinically into a worse prognosis for affected patients. This article will describe how pregnancy-associated DIC can be diagnosed promptly and how treatment should be managed strategically. It also discusses the latest developments in our understanding of haemostatic mechanisms within the placenta and how these may have relevance to new diagnostic approaches as well as novel therapeutic modalities.

Haemostatic factors in women with history of preeclampsia

OBJECTIVE

Evaluation of haemostatic parameters--Plasma tissue plasminogen activator (t-PA), plasminogen activator inhibitor type 1 (PAI-1) and fibrin fragment D-dimer several years after the end of pregnancy to investigate if they are modified in women with history of preeclampsia (PE).

STUDY DESIGN

65 healthy women with history of PE and 54 control women with previous normal pregnancy were enrolled in this study. Groups were matched for age, time period since delivery, smoking status and alcohol consumption. t-PA, PAI-1 and fibrin fragment D-dimer antigen levels were quantified using standards commercial ELISA methods. Plasma fibrinogen was measured using automated capillary zone electrophoresis.

RESULTS

Systolic and diastolic blood pressures were higher in women with history of PE. Levels of t-PA, PAI-1 and fibrinogen were similar between groups as well as the t-PA/PAI-1 ratio. A significant increase in D-dimer levels was observed in women with history of PE.

CONCLUSION

The increase in D-dimer level suggests an abnormal haemostatic potential namely increased intravascular coagulation. This, together with the increased blood pressure, can reflect a tendency for an increased risk of cardiovascular/thrombotic events later in life.

Variations in fibrinolytic parameters and inhibin-A in pregnancy: related hypertensive disorders

BACKGROUND

The mechanisms leading to pregnancy-related hypertensive disorders, and pregnancy-induced hypertension (PIH) and pre-eclampsia (PE) in particular, are still not clear. Diagnostic criteria are clinical because specific markers of the condition are lacking. A role of the fibrinolytic system has been suggested.

OBJECTIVES

We aimed to evaluate the behavior of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor type 1 (PAI-1), PAI-2, and the placental hormone inhibin-A in women with a normal pregnancy vs. women with pregnancies complicated by PIH or PE.

METHODS

Blood samples were drawn between the 25th and 30th gestational week (GW) and between the 31st and 36th GW in order to assay t-PA, PAI-1, PAI-2 and inhibin-A; routine biochemical exams, ultrasonography umbilical artery pulsatility index (PI), placental weight and newborn weight were measured.

RESULTS

In pregnancies complicated by hypertensive disorders, PAI-1 levels were higher than in controls and increased significantly after the 25th GW, especially in PE, as did inhibin-A. PAI-2 levels were significantly lower after the 30th GW in patients with PIH and PE. The PAI-1/PAI-2 ratio was significantly higher in PE patients than in controls as of the 25th GW, but only after the 30th GW in patients with PIH. Inhibin-A was significantly correlated with fibrinolytic parameters, and inversely with newborn weight. Receiver-operator characteristic curves for PAI-1 and inhibin-A showed a high sensitivity and specificity for PE. PAI-2 correlated with newborn and placental weight, and inversely with PI of the umbilical artery.

CONCLUSIONS

Fibrinolytic tests (especially PAI-1) and inhibin-A monitoring during pregnancy may help in the early diagnosis of pregnancy-related hypertensive disorders.