Enhanced thrombin generation in normal and hypertensive pregnancy

Immunometabolic adaptation in monocytes underpins functional changes during pregnancy

Metabolic heterogeneity is a determinant of immune cell function. The normal physiological metabolic reprogramming of pregnancy that ensures the fuel requirements of mother and baby are met, might also underpin changes in immunity that occur with pregnancy and manifest as altered responses to pathogens and changes to autoimmune disease symptoms. Using peripheral blood from pregnant women at term, we reveal that monocytes lose M2-like and gain M1-like properties accompanied by reductions in mitochondrial mass, maximal respiration, and cardiolipin content in pregnancy; glycolysis is unperturbed. We establish that muramyl dipeptide (MDP)-stimulated cytokine production relies on oxidative metabolism, then show in pregnancy reduced cytokine production in response to MDP but not LPS. Overall, mitochondrially centered metabolic capabilities of late gestation monocytes are down-regulated revealing natural plasticity in monocyte phenotype and function that could reveal targets for improving pregnancy outcomes but also yield alternative therapeutic approaches to diverse metabolic and/or immune-mediated diseases beyond pregnancy.

Deciphering the immunological interactions: targeting preeclampsia with Hydroxychloroquine's biological mechanisms

Preeclampsia (PE) is a complex pregnancy-related disorder characterized by hypertension, followed by organ dysfunction and uteroplacental abnormalities. It remains a major cause of maternal and neonatal morbidity and mortality worldwide. Although the pathophysiology of PE has not been fully elucidated, a two-stage model has been proposed. In this model, a poorly perfused placenta releases various factors into the maternal circulation during the first stage, including pro-inflammatory cytokines, anti-angiogenic factors, and damage-associated molecular patterns into the maternal circulation. In the second stage, these factors lead to a systemic vascular dysfunction with consecutive clinical maternal and/or fetal manifestations. Despite advances in feto-maternal management, effective prophylactic and therapeutic options for PE are still lacking. Since termination of pregnancy is the only curative therapy, regardless of gestational age, new treatment/prophylactic options are urgently needed. Hydroxychloroquine (HCQ) is mainly used to treat malaria as well as certain autoimmune conditions such as systemic lupus and rheumatoid arthritis. The exact mechanism of action of HCQ is not fully understood, but several mechanisms of action have been proposed based on its pharmacological properties. Interestingly, many of them might counteract the proposed processes involved in the development of PE. Therefore, based on a literature review, we aimed to investigate the interrelated biological processes of HCQ and PE and to identify potential molecular targets in these processes.

Quantitative Proteomics of Maternal Blood Plasma in Isolated Intrauterine Growth Restriction

Intrauterine growth restriction (IUGR) remains a significant concern in modern obstetrics, linked to high neonatal health problems and even death, as well as childhood disability, affecting adult quality of life. The role of maternal and fetus adaptation during adverse pregnancy is still not completely understood. This study aimed to investigate the disturbance in biological processes associated with isolated IUGR via blood plasma proteomics. The levels of 125 maternal plasma proteins were quantified by liquid chromatography-multiple reaction monitoring mass spectrometry (LC-MRM MS) with corresponding stable isotope-labeled peptide standards (SIS). Thirteen potential markers of IUGR (Gelsolin, Alpha-2-macroglobulin, Apolipoprotein A-IV, Apolipoprotein B-100, Apolipoprotein(a), Adiponectin, Complement C5, Apolipoprotein D, Alpha-1B-glycoprotein, Serum albumin, Fibronectin, Glutathione peroxidase 3, Lipopolysaccharide-binding protein) were found to be inter-connected in a protein-protein network. These proteins are involved in plasma lipoprotein assembly, remodeling, and clearance; lipid metabolism, especially cholesterol and phospholipids; hemostasis, including platelet degranulation; and immune system regulation. Additionally, 18 proteins were specific to a particular type of IUGR (early or late). Distinct patterns in the coagulation and fibrinolysis systems were observed between isolated early- and late-onset IUGR. Our findings highlight the complex interplay of immune and coagulation factors in IUGR and the differences between early- and late-onset IUGR and other placenta-related conditions like PE. Understanding these mechanisms is crucial for developing targeted interventions and improving outcomes for pregnancies affected by IUGR.

Iliac vein stenting and pregnancy

Venous stenting is the mainstay treatment of symptomatic iliofemoral venous outflow obstruction. However, because pregnancy and the postpartum period are hypercoagulable, concerns exist regarding stent placement in women of childbearing age. We performed a systematic review up to April 2023 of studies reporting on the performance of venous stents in women who subsequently became pregnant. The data collected included demographics, indication for stenting, stent characteristics, stent-related complications, incidence of venous thromboembolism, medical management during pregnancy, and follow-up. The indications for stenting included acute iliofemoral deep vein thrombosis in 39 patients (51%), nonthrombotic iliac vein lesions in 35 (46%), and post-thrombotic lesions in 2 patients. A total of 76 women with 87 subsequent pregnancies after stenting were included. Of the 76 women, 1 (1.14%) experienced stent occlusion, 2 (2.29%) developed asymptomatic nonocclusive in-stent thrombus, and 2 (2.29%) experienced permanent stent compression. The only patency loss occurred because of inadequate anticoagulation therapy in a patient with antiphospholipid antibodies. The two cases of permanent compression occurred in an arterial stent and a balloon-fenestrated Vici stent (Boston Scientific). Venous stents performed well through pregnancy and can be safely used in women of childbearing age. Given the increased risk of venous thromboembolism and the low bleeding risk, it is prudent to recommend anticoagulation therapy for all stented patients until more data are available.

Outcomes of dedicated iliac venous stents during pregnancy and postpartum

OBJECTIVE

The aim of this study was to assess the performance of dedicated iliac venous stents during subsequent pregnancy and postpartum, including stent patency and stent integrity, as well as incidence of venous thromboembolism and bleeding complications.

METHODS

This study included retrospective analysis of prospectively collected data of patients attending a private vascular practice. Women of child-bearing age who had received dedicated iliac venous stents were included in a surveillance program and then, for any subsequent pregnancies, followed the same pregnancy care protocol. This included an antithrombotic regime of 100 mg aspirin daily until gestation week 36, and subcutaneous enoxaparin at a dose dependent on risk of thrombosis: low-risk patients, those stented for non-thrombotic iliac vein lesion, received a prophylactic dose of 40 mg/day from the third trimester; high-risk patients, those stented for thrombotic indication, received a therapeutic dose of 1.5 mg/kg/day from the first trimester. All women underwent follow-up with duplex ultrasound assessment of stent patency during pregnancy and at 6 weeks postpartum.

RESULTS

Data was analyzed for a total of 10 women and 13 post-stent pregnancies. Stents were placed for non-thrombotic iliac vein lesions in seven patients, and for post-thrombotic stenoses in three patients. All stents were dedicated venous stents, and four crossed the inguinal ligament. All stents remained patent during pregnancy, at 6 weeks postpartum, and latest follow-up (median time post-stent, 60 months). There were no cases of deep vein thrombosis or pulmonary embolism, and no bleeding complications. There was only one reintervention case due to in-stent thrombus, and one case of asymptomatic stent compression.

CONCLUSIONS

Dedicated venous stents performed well through pregnancy and post-partum. A protocol including the use of low dose antiplatelets in combination with anticoagulation at either a prophylactic or therapeutic dose depending on the patient's risk profile appears safe and effective.

Perturbations in kinetics of the thrombin generation assay identify women at risk of preeclampsia in the first trimester and provide the rationale for a preventive approach

BACKGROUND

Activation of the coagulation system and increased thrombin generation have been implicated in the pathophysiology of preeclampsia, and this rationale supports the administration of low-molecular-weight heparin to prevent this syndrome in patients at risk. Yet, randomized trials of this prophylactic measure have yielded contradictory results. A possible explanation is that only a subset of patients with preeclampsia have excessive thrombin generation and would benefit from the administration of low-molecular-weight heparin. Therefore, the key questions are whether and when patients who subsequently develop preeclampsia present evidence of abnormal thrombin generation.

OBJECTIVE

This study aimed to determine (1) the kinetics of thrombin generation throughout gestation in women with a normal pregnancy and in those with early and late preeclampsia, and (2) the diagnostic performance of in vivo thrombin generation parameters to predict the development of preeclampsia.

STUDY DESIGN

This retrospective, nested case-control study was based on a prospective longitudinal cohort of singleton gestations. Cases comprised women who developed preeclampsia (n=49), and controls consisted of patients with a normal pregnancy (n=45). Preeclampsia was classified into early-onset (n=24) and late-onset (n=25). Longitudinal changes in the parameters of the thrombin generation assay (lag time, time to peak thrombin concentration, peak thrombin concentration, endogenous thrombin generation, and velocity index) throughout gestation were compared between the study groups, and normal pregnancy percentiles were derived from the control group. We tested whether a single parameter or a combination of parameters, derived from the kinetics of thrombin generation, could identify patients who subsequently developed preeclampsia. Time-related parameters <10th percentile were considered short, and concentration-related parameters >90th percentile were considered high.

RESULTS

(1) Patients who developed preeclampsia (early- and late-onset) had abnormal thrombin generation kinetics as early as 8 to 16 weeks of pregnancy; (2) patients with a combination of a short lag time and high peak thrombin concentration at 8 to 16 weeks of pregnancy had an odds ratio of 43.87 for the subsequent development of preeclampsia (area under the curve, 0.79; sensitivity, 56.8%; specificity, 92.7%; positive likelihood ratio, 7.76); (3) at 16 to 22 weeks of gestation, patients with a combination of a short lag time and a high velocity index had an odds ratio of 16 for the subsequent development of preeclampsia (area under the curve, 0.78; sensitivity, 62.2%; specificity, 92.5%; positive likelihood ratio, 8.29).

CONCLUSION

During early pregnancy, the thrombin generation assay can identify the subset of patients at a greater risk for the development of preeclampsia owing to accelerated and enhanced production of thrombin. This observation provides a rationale for testing the efficacy of low-molecular-weight heparin in this subset of patients. We propose that future research on the efficacy of low-molecular-weight heparin and other interventions targeting the coagulation system to prevent preeclampsia should be focused on patients with abnormal kinetics of thrombin generation.

Pathophysiological, immunogenetic, anatomopathological profile of thrombophilia in pregnancy

Thrombophilic states have been associated with early and/or late pregnancy loss and possibly other severe obstetrical complications. Pregnancy-induced hypercoagulability, increased stasis, and the consequences of inherited and acquired thrombophilia are just a few of the factors that contribute to the development of thrombosis in pregnancy. In this review, we illustrate the impact that these factors have on the development of thrombophilia during pregnancy. We also explore how thrombophilia impact pregnancy outcomes. Next, we discuss how human leukocyte antigen G plays a part in thrombophilia during pregnancy by regulating cytokine release to prevent trophoblastic cell invasion and maintain local immunotolerance constant. Human leukocyte antigen class E is briefly explored with thrombophilia in pregnancy. Regarding the anatomopathologic aspect, we describe the different histopathological lesions of the placenta found in women with thrombophilia.

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.

How can Secondary Thromboprophylaxis in High-Risk Pregnant Patients be Improved?

Low-molecular-weight heparin (LMWH) is suggested for thromboprophylaxis in pregnant women with previous venous thromboembolism (VTE). Anyway, there is only limited amount of studies evaluating the effect of LMWH on hemostatic parameters during pregnancy of patients with previous VTE and the need of secondary thromboprophylaxis. We therefore provide results of prospective and longitudinal assessment of changes in hemostasis in high-risk pregnant women at four times during pregnancy (T1–T4) and one time after the postpartum period (T5) used for individualized modification of thromboprophylaxis. In this study, the results of coagulation factor VIII (FVIII) and protein S (PS) activity, ProC Global ratio and anti-Xa activity were evaluated. Despite the thromboprophylaxis, an increased predisposition to thromboembolic complications was detected (significant increase in FVIII activity and decrease in PS function, ProC Global ratio not normalized even after the postpartum period – p < .0001 between controls and T5 for PS and ProC Global). These results indicate that hemostasis may not be restored even 6 to 8 weeks after delivery and pose the question when is it safe to withdraw the anticoagulant thromboprophylaxis in high-risk patients with prior VTE.

DIC in Pregnancy - Pathophysiology, Clinical Characteristics, Diagnostic Scores, and Treatments

Obstetrical hemorrhage and especially DIC (disseminated intravascular coagulation) is a leading cause for maternal mortality across the globe, often secondary to underlying maternal and/or fetal complications including placental abruption, amniotic fluid embolism, HELLP syndrome (hemolysis, elevated liver enzymes and low platelets), retained stillbirth and acute fatty liver of pregnancy. Various obstetrical disorders can present with DIC as a complication; thus, increased awareness is key to diagnosing the condition. DIC patients can present to clinicians who may not be experienced in a variety of aspects of thrombosis and hemostasis. Hence, DIC diagnosis is often only entertained when the patient already developed uncontrollable bleeding or multi-organ failure, all of which represent unsalvageable scenarios. Beyond the clinical presentations, the main issue with DIC diagnosis is in relation to coagulation test abnormalities. It is widely believed that in DIC, patients will have prolonged prothrombin time (PT) and partial thromboplastin time (PTT), thrombocytopenia, low fibrinogen, and raised D-dimers. Diagnosis of DIC can be elusive during pregnancy and requires vigilance and knowledge of the physiologic changes during pregnancy. It can be facilitated by using a pregnancy specific DIC score including three components: 1) fibrinogen concentrations; 2) the PT difference - relating to the difference in PT result between the patient's plasma and the laboratory control; and 3) platelet count. At a cutoff of ≥26 points, the pregnancy specific DIC score has 88% sensitivity, 96% specificity, a positive likelihood ratio (LR) of 22, and a negative LR of 0.125. Management of DIC during pregnancy requires a prompt attention to the underlying condition leading to this complication, including the delivery of the patient, and correction of the hemostatic problem that can be guided by point of care testing adjusted for pregnancy.

Nonovert disseminated intravascular coagulation (DIC) in pregnancy: a new scoring system for the identification of patients at risk for obstetrical hemorrhage requiring blood product transfusion

BACKGROUND

Nonovert disseminated intravascular coagulation (DIC) is a subclinical hemostatic dysfunction that has not yet reached the decompensation stage. The detection of pregnant patients at this stage may assist in the identification of those who will develop severe obstetrical hemorrhage, as it is one of the leading causes for preventable maternal mortality. Currently, nonovert DIC is diagnosed by a scoring system based on nonpregnant patients, originally generated by the International Society on Thrombosis and Hemostasis (ISTH), which does not address the physiologic changes of the hemostatic system during pregnancy.

OBJECTIVES

(1) To develop a pregnancy-specific nonovert DIC score, (2) to determine the diagnostic performance of this score in detecting women at risk for obstetrical hemorrhage requiring blood product transfusion, and (3) to compare it to the existing ISTH nonovert DIC score.

STUDY DESIGN

This retrospective study has longitudinal and cross-sectional components and includes three steps: (1) characterization of the longitudinal changes in the components of modified ISTH nonovert DIC scores, including these parameters - fibrinogen, antithrombin III, protein C, prothrombin time (PT), platelets, thrombin-antithrombin (TAT) complex, and D-dimer - during gestation in a group of normal pregnancies (n = 50); (2) development of a pregnancy-specific nonovert DIC score in a cross-sectional design of high-risk (n = 152) and control (n = 50) pregnancies, based on the predictive performance of each analyte for the detection of women at risk for obstetrical hemorrhage requiring blood product transfusion and a logistic regression model; and (3) comparison between the diagnostic performance of the pregnancy-specific nonovert DIC score and the modified ISTH nonovert DIC score to detect, upon admission, women who are at increased risk for subsequent development of obstetrical hemorrhage requiring blood product transfusion.

RESULTS

(1) The study cohort included 202 patients, of which 21 (10%) had obstetrical hemorrhage that required blood product transfusion and were considered to have nonovert DIC; (2) using the nonpregnant ISTH nonovert DIC score, 92% of the patients had a D-dimer concentration above the 0.5 mg/L threshold, and only 2% were identified to have a low fibrinogen concentration (<100 mg/dL); thus, this scoring system was unable to identify any of the patients with nonovert DIC based on the suggested cutoff of a score of ≥5; (3) the parameters included in the pregnancy-specific nonovert DIC score were selected based on their contribution to the performance of the model for the prediction of women at risk for obstetrical hemorrhage requiring blood product transfusion; as a result, we excluded the PT difference parameter from the score and the TAT complex concentration was added; and (4) a pregnancy-specific nonovert DIC score of ≥3 had a sensitivity of 71.4% and a specificity of 77.9% to identify patients at risk for obstetrical hemorrhage requiring blood product transfusion.

CONCLUSION

We propose (1) a pregnancy-specific nonovert DIC score adjusted for the physiologic changes in the hemostatic system during gestation; and (2) that the pregnancy-specific nonovert DIC score can be a useful tool for the identification of patients at risk for obstetrical hemorrhage requiring blood product transfusion.

Comparison of doses of heparin for venous thromboembolism and bleeding in pregnant women

The evaluation criteria for dosage of low-molecular-weight heparin (LMWH) for pregnant women at high risk of venous thromboembolism (VTE) remain unclear. A retrospective study was performed to investigate the relative appropriate LMWH administration strategy and dosage for pregnant women at risk of VTE. 219 pregnant women with perinatal and postpartum VTE were reviewed and divided into group A (fixed dose group: n=73, 5000 IU dalteparin daily for all women), group B (weight group: n=73, 2500 IU dalteparin daily for women less than 50 kg; 5000 IU dalteparin daily for women more than 50 kg), and group C (anti-factor Xa (FXa) + weight group: n=73, 5000 IU once daily for women less than 50 kg; 7500 IU once daily for women weighing 50-80 kg; 10,000 IU once daily for women weighing over 80 kg). Further dose administration was adjusted according to peak anti-FXa level, maintaining the peak at the 0.5-1.0 IU/mL range. Women in group C presented lower incidence of VTE and other pregnancy complications than group A and group B. Adjusting the dosage of LMWH according to both weight and anti-FXa level of pregnant women not only prevented VTE but also reduced the risk of postpartum hemorrhage induced by LMWH administration. In addition, adjusting the dose of LMWH according to anti-FXa level and body weight also affected the recurrence of VTE and the occurrence of postpartum hemorrhage in pregnant women.

Non-obstetric complications in preeclampsia

Preeclampsia is a multisystem disorder of pregnancy that remains a leading cause of maternal and foetal morbidity and mortality. It is still an underestimated risk factor for future cardiovascular, cerebrovascular, and kidney disease, developing often in the perimenopausal period of a woman's life. It remains unclear whether preeclampsia is an individual risk factor for future cardiovascular, cerebrovascular, and renal events or an early marker of women with high-risk profiles for these diseases. Risk factors for cardiovascular disorders and preeclampsia are very similar and include the following: obesity, dyslipidaemia, insulin resistance, pro-inflammatory and hypercoagulable state, and endothelial dysfunction. Thus, the pregnancy can only be a trigger for cardiovascular alterations that manifest in development of preeclampsia. On the other hand, there is strong evidence that changes in cardiovascular, endothelial, and metabolic systems occurring in the course of preeclampsia may not fully recover after delivery and can be a cause of future disease, especially in the presence of other metabolic risk factors regarding, for example, perimenopause. In this review the authors present current knowledge about short- and long-term maternal consequences of preeclampsia, such as: cardiovascular disease, cerebrovascular incidents (posterior reversible encephalopathy and stroke), kidney injury (including the risk of end-stage renal disease), liver failure, and coagulopathy (thrombocytopenia and disseminated intravascular coagulation).

The profiles of soluble adhesion molecules in the "great obstetrical syndromes". J Matern Fetal Neonatal Med 2018;32:2113-2136. [PMID: 29320948 DOI: 10.1080/14767058.2018.1427058]

OBJECTIVE

The objective of this study was to determine the profiles of maternal plasma soluble adhesion molecules in patients with preeclampsia, small-for-gestational-age (SGA) fetuses, acute pyelonephritis, preterm labor with intact membranes (PTL), preterm prelabor rupture of the membranes (preterm PROM), and fetal death.

MATERIALS AND METHODS

A cross-sectional study was conducted to determine maternal plasma concentrations of sE-selectin, sL-selectin, and sP-selectin as well as sICAM-1, sVCAM-1, and sPECAM-1 in patients with (1) an uncomplicated pregnancy (control, n = 100); (2) preeclampsia (n = 94); (3) SGA fetuses (in women without preeclampsia/hypertension, n = 45); (4) acute pyelonephritis (n = 25); (5) PTL (n = 53); (6) preterm PROM (n = 24); and (7) fetal death (n = 34). Concentrations of soluble adhesion molecules and inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-8) were determined with sensitive and specific enzyme-linked immunoassays.

RESULTS

In comparison to women with a normal pregnancy, (1) women with preeclampsia had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1, and a lower concentration of sL-selectin (all p values < .001); (2) patients with SGA fetuses had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1 (all p values < .05); (3) patients with a fetal death had higher median concentrations of sE-selectin and sP-selectin (all p values < .05); (4) patients with acute pyelonephritis had higher median plasma concentrations of sE-selectin, sICAM-1, and sVCAM-1 (all p values < .001); (5) patients with preeclampsia and acute pyelonephritis, plasma concentrations of sVCAM-1, sE-selectin, and sP-selectin correlated with those of the proinflammatory cytokines TNF-α and interleukin (IL)-8 (all p values < .05); (6) patients with PTL had a higher median concentration of sP-selectin and a lower median concentration of VCAM-1 (all p values < .05); and (7) women with preterm PROM had lower median concentrations of sL-selectin and sVCAM-1 (all p values < .05).

CONCLUSIONS

The results of this study show that endothelial cell activation/dysfunction reflected by the plasma concentration of sE-selectin is not specific to preeclampsia but is present in pregnancies complicated by SGA fetuses, acute pyelonephritis, and fetal death. Collectively, we report that each obstetrical syndrome appears to have a stereotypical profile of soluble adhesion molecules in the peripheral circulation.

Role of Plasminogen Activator Inhibitor Type 1 in Pathologies of Female Reproductive Diseases

Normal pregnancy is a state of hypercoagulability with diminishing fibrinolytic activity, which is mainly caused by an increase of plasminogen activator inhibitor type 1 (PAI-1). PAI-1 is the main inhibitor of plasminogen activators, including tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). In human placentas, PAI-1 is expressed in extravillous interstitial trophoblasts and vascular trophoblasts. During implantation and placentation, PAI-1 is responsible for inhibiting extra cellular matrix (ECM) degradation, thereby causing an inhibition of trophoblasts invasion. In the present study, we have reviewed the literature of various reproductive diseases where PAI-1 plays a role. PAI-1 levels are increased in patients with recurrent pregnancy losses (RPL), preeclampsia, intrauterine growth restriction (IUGR), gestational diabetes mellitus (GDM) in the previous pregnancy, endometriosis and polycystic ovary syndrome (PCOS). In general, an increased expression of PAI-1 in the blood is associated with an increased risk for infertility and a worse pregnancy outcome. GDM and PCOS are related to the genetic role of the 4G/5G polymorphism of PAI-1. This review provides an overview of the current knowledge of the role of PAI-1 in reproductive diseases. PAI-1 represents a promising monitoring biomarker for reproductive diseases and may be a treatment target in the near future.

The pattern and magnitude of "in vivo thrombin generation" differ in women with preeclampsia and in those with SGA fetuses without preeclampsia

OBJECTIVE

We aimed to determine the differences in the pattern and magnitude of thrombin generation between patients with preeclampsia (PE) and those with a small-for-gestational-age (SGA) fetus.

METHODS

This cross-sectional study included women in the following groups: (1) normal pregnancy (NP) (n = 49); (2) PE (n = 56); and (3) SGA (n = 28). Maternal plasma thrombin generation (TGA) was measured, calculating: (a) lag time (LT); (b) velocity index (VI); (c) peak thrombin concentration (PTC); (d) time-to-peak thrombin concentration (TPTC); and (e) endogenous thrombin potential (ETP).

RESULTS

(1) The median TPTC, VI, and ETP differed among the groups (p = .001, p = .006, p < .0001); 2) the median ETP was higher in the PE than in the NP (p < .0001) and SGA (p = .02) groups; 3) patients with SGA had a shorter median TPTC and a higher median VI than the NP (p = .002, p = .012) and PE (p < .0001, p = .006) groups.

CONCLUSIONS

(1) Patients with PE had higher in vivo thrombin generation than women with NP and those with an SGA fetus; (2) the difference in TGA patterns between PE and SGA suggests that the latter group had faster TGA, while patients with PE had a longer reaction, generating more thrombin. This observation is important for the identification of a subset of patients who might benefit from low molecular-weight heparin.

Tissue factor activity in women with preeclampsia or SGA: a potential explanation for the excessive thrombin generation in these syndromes

OBJECTIVE

The aim of this study was to determine whether the activity of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in the plasma of women with preeclampsia (PE) and small for gestational age (SGA) neonate differ from that of normal pregnant women and whether they are related to specific placental lesions.

METHODS

This cross-sectional study included the following groups: (1) normal pregnancy (n = 68); (2) PE (n= 128); and (3) SGA (n = 56). Maternal plasma TF and TFPI activity was determined with chromogenic assays.

RESULTS

(1) The median maternal plasma TF activity, but not TFPI activity, differed among the study groups (p < .0001 and p = .4, respectively); (2) patients with PE had a higher median maternal plasma TF activity than women with normal pregnancies (p < .0001) and mothers with SGA fetuses (p = .002); (3) among patients with PE, those with distal villous hypoplasia had a higher median maternal TF activity than those without these placental lesions (p = .018); and (4) following adjustment for confounding variables, maternal plasma TF and TFPI activity were not associated with an SGA neonate.

CONCLUSIONS

Plasma TF activity is higher in women with PE than in those with SGA or normal pregnancies. We propose that these changes may be responsible, at least in part, for the increased in-vivo thrombin generation observed in this obstetrical syndrome.

Blood laboratory testing for early prediction of preeclampsia: chasing the finish line or at the starting blocks?

Preeclampsia (PE) affects 2-8% of pregnancies worldwide, thus representing an important cause of maternal and neonatal morbidity, up to death. Many studies have been designed to identify putative biomarkers for accurate and timely diagnosing PE, but only some of them were focused on specific and sensitive biomarkers for early prediction of this life-threatening condition. In particular, some prospective studies aimed to investigate the predictive role of circulating biomarkers before 20 weeks of gestation in the general pregnant population yielded conflicting results. This article is hence centered on results obtained in studies investigating the predictive performances of angiogenic, anti-angiogenic, inflammatory, endocrine, and epigenetic biomarkers. The available evidence suggests that angiogenic and anti-angiogenic molecules, in particular the sFlt1:PlGF ratio, may be considered the biomarkers with the best diagnostic performance in the second trimester. However, doubts remain about their use in clinical settings before the 20th gestational week. Even lower evidence is available for other biomarkers, due to the fact that some positive results have not been confirmed in ensuing investigations, whereas unresolved analytical issues still contribute to make their clinical reliability rather questionable. Differential expression of microRNAs seems also a promising evidence for early prediction of PE, but additional research and well-designed prospective studies are needed to identify and validate routine predictive tests. KEY MESSAGES Preeclampsia affects 2-8% of pregnant women worldwide, thus remaining one of the leading causes of maternal and neonatal morbidity and mortality. Several studies have investigated the predictive role of circulating biomarkers before 20th week of gestation with conflicting results. Additional research and well-designed prospective studies are needed to identify and validate predictive tests in clinical practice.

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.

Is plasminogen activator inhibitor-1 a physiological bottleneck bridging major depressive disorder and cardiovascular disease?

Major depressive disorder (MDD) is estimated to affect one in twenty people worldwide. MDD is highly comorbid with cardiovascular disease (CVD), itself one of the single largest causes of mortality worldwide. A number of pathological changes observed in MDD are believed to contribute to the development of cardiovascular disease, although no single mechanism has been identified. There are also no biological markers capable of predicting the future risk of developing heart disease in depressed individuals. Plasminogen activator inhibitor-1 (PAI-1) is a prothrombotic plasma protein secreted by endothelial tissue and has long been implicated in CVD. An expanding body of literature has recently implicated it in the pathogenesis of major depressive disorder as well. In this study, we review candidate pathways implicating MDD in CVD and consider how PAI-1 might act as a mediator by which MDD induces CVD development: chiefly through sleep disruption, adiposity, brain-derived neurotrophic factor (BDNF) metabolism, systemic inflammation and hypothalamic-pituitary-adrenal (HPA)-axis dysregulation. As both MDD and CVD are more prevalent in women than in men, and incidence of either condition is dramatically increased during reproductive milestones, we also explore hormonal and sex-specific associations between MDD, PAI-1 and CVD. Of special interest is the role PAI-1 plays in perinatal depression and in cardiovascular complications of pregnancy. Finally, we propose a theoretical model whereby PAI-1 might serve as a useful biomarker for CVD risk in those with depression, and as a potential target for future treatments.

Pharmacology of Heparin and Related Drugs

Heparin has been recognized as a valuable anticoagulant and antithrombotic for several decades and is still widely used in clinical practice for a variety of indications. The anticoagulant activity of heparin is mainly attributable to the action of a specific pentasaccharide sequence that acts in concert with antithrombin, a plasma coagulation factor inhibitor. This observation has led to the development of synthetic heparin mimetics for clinical use. However, it is increasingly recognized that heparin has many other pharmacological properties, including but not limited to antiviral, anti-inflammatory, and antimetastatic actions. Many of these activities are independent of its anticoagulant activity, although the mechanisms of these other activities are currently less well defined. Nonetheless, heparin is being exploited for clinical uses beyond anticoagulation and developed for a wide range of clinical disorders. This article provides a "state of the art" review of our current understanding of the pharmacology of heparin and related drugs and an overview of the status of development of such drugs.

Adjusting enoxaparin dosage according to anti-FXa levels and pregnancy outcome in thrombophilic women. A randomised controlled trial

Women with thrombophilias and previous placenta-mediated pregnancy complications (PMPC) have an increased risk of both recurrent PMPC and venous thromboembolism (VTE) during subsequent pregnancies. We aimed to examine whether enoxaparin dose adjusted according to anti-factor Xa levels compared to a fixed dose would reduce the risk of PMPC in subsequent pregnancies. In a randomised trial, conducted at a single teaching hospital, pregnant women with thrombophilia and previous PMPC were enrolled in a 1:1 ratio to either a fixed dose of 40 mg daily enoxaparin or adjusted dose according to anti-factor Xa plasma levels. The primary outcome was a composite that included any of the following: pregnancy loss after enrollment, pre-eclampsia, birthweight <10th percentile, placental abruption, or VTE. Overall, 144 women were needed to detect a decrease of 20 % in the incidence of the composite outcome among the adjusted dose group. Between 2009 and 2015, 144 women consented; four in the fixed-dose group were excluded. Overall, 66 and 74 in the fixed- and adjusted-dose groups, respectively, were included. Demographic and obstetric characteristics were comparable. Composite outcome occurred in 12 (18.2 %) and 20 (27.0 %) women in the fixed- and adjusted-dose groups, respectively (p=0.24). Gestational age at delivery, preterm births, and birthweights were similar between the two groups. In conclusion, dose of enoxaparin adjusted according to anti-factor Xa levels compared to fixed dose, does not reduce the risk of PMPC recurrence in thrombophilic women.

Coagulation and Fibrinolysis in Preeclampsia and Neonates

Coagulation and fibrinolysis were determined in 67 Indonesian women admitted to the University Hospitals for delivery in Medan. They were diagnosed to be at term gestation (mean 39.3 ± 1.1 weeks) with moderate and severe preeclampsia (n=32) and in labor, and 8 had preterm labor (gestation mean 33.5 ± 2.6 weeks). Twenty-seven normal pregnant women in labor (gestation mean 39.7 ± 1.0 weeks) served as controls. Cord blood from 23 neonates from normal pregnancy and 31 neonates from preeclampsia was also evaluated. Preeclamptic women in labor showed further enhanced coagulation activation (F1+2) with raised urokinase-like plasminogen activator (u-PA) activity and reduced plasminogen activator inhibitor-2 (PAI-2) levels. In preterm preeclampsia, significantly reduced antithrombin III (ATIII) and PAI-2 levels with further elevated tissue-type PA (t-PA) antigen and plasminogen activator inhibitor-1 (PAI-1) antigen were seen compared to normal pregnancy. These would suggest a state of enhanced thrombin generation with elevated fibrinolytic/inhibitor proteins in preterm preeclampsia. The reduced PAI-2 levels seen in preeclampsia have been suggested to be associated with reduced placental function. Neonates born to mothers of either normal pregnancy or preeclampsia at term showed similar hemostatic changes with reduced fibrinogen, ATIII, t-PA, u-PA antigen, PAI-1 levels, and coagulation activation compared to their respective maternal plasma levels. No significant differences in hemostatic parameters studied between the neonates of both cohorts were seen, and this would suggest that the neonates were protected from the adverse effects of preeclampsia and their hemostatic system was physiologically balanced.

The Influence of Labor and Placental Separation on Hemostasis in Term Pregnancy

We studied the hemostatic effects in 68 term preg nant subjects with normal pregnancy (n = 39), gestational diabetes mellitus (n = 21), pregnancy-induced hypertension (n = 8), during labor, after placental separation, and at 24 hours postpartum. During labor, a hypercoagulable state with en hanced fibrinolysis and platelet activation along with elevated plasminogen activator inhibitor-1 and plasminogen activator inhibitor-2 were seen. In all cases following placental separa tion, enhanced fibrinolysis persisted with further elevated tissue plasminogen activator antigen and D-dimer levels, increased thrombin generation and platelet activation with decreasing plasminogen activator inhibitor-1 levels. By 24 hours postpar tum, thrombin generation (thrombin-antithrombin complex) decreased to a nonpregnant level except for pregnancy induced hypertension, but enhanced prothrombin activation (F1+2) was evident in normal, gestational diabetes mellitus and pregnancy- induced hypertension. Reduced total protein S and antithrom bin III activity with normal protein C and elevated fibrinogen levels seen during labor were not affected by delivery. How ever, although factor VII showed a decreasing trend at 24 hours postpartum it remained elevated above the normal nonpregnant level. At 24 hours postpartum, a hypercoagulable state still persisted in normal, gestational diabetes mellitus and preg nancy-induced hypertension term pregnancy accompanied by enhanced fibrinolysis and elevated plasminogen substrate for fibrinolysis, suggesting a critical dynamic equilibrium between a thrombotic and hemorrhagic state.

Thrombin Generation by Fetoscopic Trauma to the Fetal Membranes: An in vivo and in vitro Study

OBJECTIVE

We first aimed to investigate in vivo thrombin generation induced by fetoscopy, and second we used term membrane explants for measurement of thrombin generation, thrombin receptor location and induction of selected matrix metalloproteinases (MMPs) in tissue culture.

MATERIALS AND METHODS

In vivo study (37 cases): samples of amniotic fluid were taken at the beginning and end of fetoscopy (mean gestational age 26.7 weeks) and analyzed by ELISA for thrombin-antithrombin complexes. In vitro study: fetal membranes were put in culture and punctured for measurement of thrombin generation by calibrated automated thrombography and ELISA. Induction of MMP-9 and MMP-2 was analyzed by zymography. PAR-1 was localized by immunohistochemistry.

RESULTS

No significant increase in thrombin-antithrombin was measured in amniotic fluid obtained during fetoscopy. In vitro, thrombin generation induced by needle trauma of membrane cultures is correlated to the amount of plasma. Activity of MMP-9 but not MMP-2 was elevated in cultured membranes but could not be inhibited by a thrombin inhibitor. On histology, the thrombin receptor PAR-1 was located in the chorion and decidua, but not in the amnion.

DISCUSSION

Despite the influence of thrombin on punctured fetal membranes in vitro, the role of thrombin in iatrogenic preterm premature rupture of membranes is questionable.

Disseminated intravascular coagulation in pregnancy: insights in pathophysiology, diagnosis and management

Disseminated intravascular coagulation (DIC) is a life-threatening situation that can arise from a variety of obstetrical and nonobstetrical causes. Obstetrical DIC has been associated with a series of pregnancy complications including the following: (1) acute peripartum hemorrhage (uterine atony, cervical and vaginal lacerations, and uterine rupture); (2) placental abruption; (3) preeclampsia/eclampsia/hemolysis, elevated liver enzymes, and low platelet count syndrome; (4) retained stillbirth; (5) septic abortion and intrauterine infection; (6) amniotic fluid embolism; and (7) acute fatty liver of pregnancy. Prompt diagnosis and understanding of the underlying mechanisms of disease leading to this complication in essential for a favorable outcome. In recent years, novel diagnostic scores and treatment modalities along with bedside point-of-care tests were developed and may assist the clinician in the diagnosis and management of DIC. Team work and prompt treatment are essential for the successful management of patients with DIC.

Placental vascular pathology and increased thrombin generation as mechanisms of disease in obstetrical syndromes

Obstetrical complications including preeclampsia, fetal growth restriction, preterm labor, preterm prelabor rupture of membranes and fetal demise are all the clinical endpoint of several underlying mechanisms (i.e., infection, inflammation, thrombosis, endocrine disorder, immunologic rejection, genetic, and environmental), therefore, they may be regarded as syndromes. Placental vascular pathology and increased thrombin generation were reported in all of these obstetrical syndromes. Moreover, elevated concentrations of thrombin-anti thrombin III complexes and changes in the coagulation as well as anticoagulation factors can be detected in the maternal circulation prior to the clinical development of the disease in some of these syndromes. In this review, we will assess the changes in the hemostatic system during normal and complicated pregnancy in maternal blood, maternal–fetal interface and amniotic fluid, and describe the contribution of thrombosis and vascular pathology to the development of the great obstetrical syndromes.

Endocan, a putative endothelial cell marker, is elevated in preeclampsia, decreased in acute pyelonephritis, and unchanged in other obstetrical syndromes

Objective: Endocan, a dermatan sulphate proteoglycan produced by endothelial cells, is considered a biomarker for endothelial cell activation/dysfunction. Preeclampsia is characterized by systemic vascular inflammation, and endothelial cell activation/dysfunction. Therefore, the objectives of this study were to determine whether: (1) plasma endocan concentrations in preeclampsia differ from those in uncomplicated pregnancies; (2) changes in plasma endocan concentration relate to the severity of preeclampsia, and whether these changes are specific or observed in other obstetrical syndromes such as small-for-gestational age (SGA), fetal death (FD), preterm labor (PTL) or preterm prelabor rupture of membranes (PROM); (3) a correlation exists between plasma concentration of endocan and angiogenic (placental growth factor or PlGF)/anti-angiogenic factors (soluble vascular endothelial growth factor receptor or sVEGFR-1, and soluble endoglin or sEng) among pregnancies complicated by preeclampsia; and (4) plasma endocan concentrations in patients with preeclampsia and acute pyelonephritis (both conditions in which there is endothelial cell activation) differ.

Method: This cross-sectional study included the following groups: (1) uncomplicated pregnancy (n = 130); (2) preeclampsia (n = 102); (3) pregnant women without preeclampsia who delivered an SGA neonate (n = 51); (4) FD (n = 49); (5) acute pyelonephritis (AP; n = 35); (6) spontaneous PTL (n = 75); and (7) preterm PROM (n = 64). Plasma endocan concentrations were determined in all groups, and PIGF, sEng and VEGFR-1 plasma concentrations were measured by ELISA in the preeclampsia group.

Results: (1) Women with preeclampsia had a significantly higher median plasma endocan concentration than those with uncomplicated pregnancies (p = 0.004); (2) among women with preeclampsia, the median plasma endocan concentration did not differ significantly according to disease severity (p = 0.1), abnormal uterine artery Doppler velocimetry (p = 0.7) or whether diagnosis was made before or after 34 weeks gestational age (p = 0.3); (3) plasma endocan concentration in women with preeclampsia correlated positively with plasma anti-angiogenic factor concentrations [sVEGFR-1: Spearman rho 0.34, p = 0.001 and sEng: Spearman rho 0.30, p = 0.003]; (4) pregnancies complicated by acute pyelonephritis with bacteremia had a lower median plasma endocan concentration than pregnancies complicated by acute pyelonephritis without bacteremia (p = 0.004), as well as uncomplicated pregnancies (p = 0.001); and (5) there was no significant difference in the median plasma endocan concentration between uncomplicated pregnancies and those complicated by FD, delivery of an SGA neonate, PTL or preterm PROM (other members of the “great obstetrical syndromes”; each p > 0.05).

Conclusion: Median maternal plasma endocan concentrations were higher preeclampsia and lower in acute pyelonephritis with bacteremia than in uncomplicated pregnancy. No significant difference was observed in the median plasma endocan concentration between other great obstetrical syndromes and uncomplicated pregnancies. The difference in the direction of change of endocan in preeclampsia and acute pyelonephritis with bacteremia may be consistent with the view that both disease entities differ in pathogenic mechanisms, despite their associations with systemic vascular inflammation and endothelial cell activation/dysfunction.

Maternal plasma fetuin-A concentration is lower in patients who subsequently developed preterm preeclampsia than in uncomplicated pregnancy: a longitudinal study

Objective: Fetuin-A is a negative acute phase protein reactant that acts as a mediator for lipotoxicity, leading to insulin resistance. Intravascular inflammation and insulin resistance have been implicated in the mechanisms of disease responsible for preeclampsia (PE). Maternal plasma concentrations of fetuin-A at the time of diagnosis of preterm PE are lower than in control patients with a normal pregnancy outcome. However, it is unknown if the changes in maternal plasma fetuin-A concentrations precede the clinical diagnosis of the disease. We conducted a longitudinal study to determine whether patients who subsequently developed PE had a different profile of maternal plasma concentrations of fetuin-A as a function of gestational age (GA) than those with uncomplicated pregnancies. Methods: A longitudinal case-control study was performed and included 200 singleton pregnancies in the following groups: (1) patients with uncomplicated pregnancies who delivered appropriate for gestational age (AGA) neonates (n = 160); and (2) patients who subsequently developed PE (n = 40). Longitudinal samples were collected at each prenatal visit and scheduled at 4-week intervals from the first or early second trimester until delivery. Plasma fetuin-A concentrations were determined by ELISA. Analysis was performed using mixed-effects models. Results: The profiles of maternal plasma concentrations of fetuin-A differ between PE and uncomplicated pregnancies. Forward analysis indicated that the rate of increase of plasma fetuin-A concentration in patients who subsequently developed PE was lower at the beginning of pregnancy (p = 0.001), yet increased faster mid-pregnancy (p = 0.0017) and reached the same concentration level as controls by 26 weeks. The rate of decrease was higher towards the end of pregnancy in patients with PE than in uncomplicated pregnancies (p = 0.002). The mean maternal plasma fetuin-A concentration was significantly lower in patients with preterm PE at the time of clinical diagnosis than in women with uncomplicated pregnancies (p < 0.05). In contrast, there were no significant differences in maternal plasma fetuin-A concentration in patients who developed PE at term. Conclusions: (1) The profile of maternal plasma concentrations of fetuin-A over time (GA) in patients who develop PE is different from that of normal pregnant women; (2) the rate of change of maternal plasma concentrations of fetuin-A is positive (increases over time) in the midtrimester of normal pregnancy, and negative (decreases over time) in patients who subsequently develop PE; (3) at the time of diagnosis, the maternal plasma fetuin-A concentration is lower in patients with preterm PE than in those with a normal pregnancy outcome; however, such differences were not demonstrable in patients with term PE.

Clinical features of isolated gestational proteinuria progressing to pre-eclampsia: retrospective observational study

OBJECTIVES

Some women with isolated gestational proteinuria (IGP) later develop hypertension and are diagnosed with pre-eclampsia (PE). This study was performed to determine whether clinical features of such proteinuria preceding PE (P-PE) differ from those of other PE (O-PE).

DESIGN

Retrospective observational study after approval of the institutional review board of ethics.

SETTING

A single university hospital. Proteinuria was defined as a protein-to-creatinine ratio (mg/mg; P/Cr) of ≥0.27 in the spot urine specimen. IGP was defined as proteinuria in the absence of hypertension. P-PE was defined as PE in which proteinuria preceded hypertension by more than 2 days.

PARTICIPANTS

All of 10 and 18 consecutive women with P-PE and O-PE, respectively, who gave birth between January 2008 and August 2013.

RESULTS

Proteinuria appeared earlier (at 30.2±3.0 vs 35.3±4.3 weeks, p=0.001), the P/Cr level was greater at birth (7.28±2.14 vs 3.19±2.49, p<0.001), net maternal weight gain during the last antenatal 1 week was greater (3.1±1.8 vs 1.3±1.7 kg, p=0.023) and length of pregnancy was shorter (32.5±1.9 vs 36.1±3.6 weeks, p=0.001) in women with P-PE than in O-PE. The duration of IGP was 10.0±5.9 days (range 3-20), and the time interval until delivery after diagnosis of PE was 6.1±8.2 days (range 0-23) in 10 women with P-PE. The P/Cr levels at birth were significantly inversely correlated with the antenatal lowest antithrombin activity and fibrinogen levels among the 28 women with PE.

CONCLUSIONS

Women with P-PE were likely to exhibit greater proteinuria in the urine, greater water retention in the interstitial space and more enhanced coagulation-fibrinolysis, thus suggesting that they may constitute a more severe form of PE than women with O-PE do.

Thrombophilia and Recurrent Pregnancy Loss: Is heparin still the drug of choice?

The association between thrombophilia and recurrent pregnancy loss (RPL) has become an undisputed fact. Thorombophilia creates a hypercoaguable state which leads to arterial and/or venous thrombosis at the site of implantation or in the placental blood vessels. Anticoagulants are an effective treatment against RPL in women with acquired thrombophilia due to antiphospholipid syndrome. The results of the use of anticoagulants for treating RPL in women with inherited thrombophilia (IT) are encouraging, but recently four major multicentre studies have shown that fetal outcomes (determined by live birth rates) may not be as favourable as previously suggested. Although the reported side-effects for anticoagulants are rare and usually reversible, the current recommendation is not to use anticoagulants in women with RPL and IT, or for those with unexplained losses. This review examines the strength of the association between thrombophilia and RPL and whether the use of anticoagulants can improve fetal outcomes.

Pregnancy and thrombophilia

The physiological changes that occur during pregnancy create a hypercoagulable milieu. This hypercoagulable state is thought to be protective, especially at the time of labor, preventing excessive hemorrhage. The presence of hereditary or acquired causes of thrombophilia during pregnancy tilts the balance in favor of unwanted venous thromboembolism and adverse pregnancy outcomes due to vascular uteroplacental insufficiency. These adverse pregnancy outcomes include recurrent pregnancy losses, intrauterine fetal death, intrauterine growth retardation, preeclampsia and placental abruption. Much of the current data with regards to the association of the different thrombophilias and pregnancy-related complications are based on retrospectively designed studies. This lack of randomization, in-homogeneity of patient populations, varying case definitions, selection biases and inadequately matched control populations, have given rise to conflicting data with regard to screening for, and treatment of, pregnant women with suspected thrombophilias. The limited data that we have support the use of anticoagulant drugs for the prevention of pregnancy-related complications in the setting of thrombophilia. Heparin and low-molecular-weight heparins are the anticoagulant drugs of choice as they do not cross the placental barrier and, hence, do not cause fetal anticoagulation or teratogenicity. Warfarin can be used from the 12th week of gestation onwards but is preferably reserved for the postpartum period.

Plasma concentrations of angiogenic/anti-angiogenic factors have prognostic value in women presenting with suspected preeclampsia to the obstetrical triage area: a prospective study

OBJECTIVE

To prospectively determine the prognostic value of maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng) and soluble vascular endothelial growth factor receptors-1 and -2 (sVEGFR-1 and -2) in identifying patients with suspected preeclampsia (PE), who require preterm delivery (PTD) or develop adverse outcomes.

STUDY DESIGN

This prospective cohort study included 85 consecutive patients who presented to the obstetrical triage area at 20-36 weeks with a diagnosis of "rule out PE." Patients were classified as: 1) those who remained stable until term (n = 37); and 2) those who developed severe PE and required PTD (n = 48). Plasma concentrations of PlGF, sEng and sVEGFR-1 and -2 were determined by ELISA.

RESULTS

Patients with PlGF/sVEGFR-1 ≤0.05 multiples of the median (MoM) or PlGF/sEng ≤0.07 MoM were more likely to deliver preterm due to PE [adjusted odd ratio (aOR) 7.4 and 8.8], and to develop maternal (aOR 3.7 and 2.4) or neonatal complications (aOR 10.0 and 10.1). Among patients who presented <34 weeks of gestation, PlGF/sVEGFR-1 ≤ 0.035 MoM or PlGF/sEng ≤0.05 MoM had a sensitivity of 89% (16/18), specificity of 96% (24/25) and likelihood ratio for a positive test of 22 to identify patients who delivered within 2 weeks. The addition of the PlGF/sVEGFR-1 ratio to standard clinical tests improved the sensitivity at a fixed false-positive rate of 3% (p = 0.004) for the identification of patients who were delivered due to PE within 2 weeks. Among patients who had a plasma concentration of PlGF/sVEGFR-1 ratio ≤0.035 MoM, 0.036-0.34 MoM and ≥0.35 MoM, the rates of PTD <34 weeks were 94%, 27% and 7%, respectively.

CONCLUSIONS

The determination of angiogenic/anti-angiogenic factors has prognostic value in patients presenting to the obstetrical triage area with suspected PE for the identification of those requiring preterm delivery and at risk for adverse maternal/neonatal outcomes.

Long-term alterations in maternal plasma proteome after sFlt1-induced preeclampsia in mice

OBJECTIVE

Preeclampsia is associated with long-term adverse maternal health, such as cardiovascular and metabolic diseases. The objective of this study was to determine whether preeclampsia in a well-characterized animal model that was induced by overexpression of soluble fms-like tyrosine kinase-1 (sFlt1) results in alterations in the maternal circulating proteome that persist long after delivery.

STUDY DESIGN

CD-1 mice at day 8 of gestation were injected with adenovirus that carried sFlt1 or the murine immunoglobulin G2α Fc fragment as control. Depleted maternal plasma was analyzed 6 months after delivery by label-free liquid chromatography-mass spectrometry assay. The tandem mass spectrometry data were searched against a mouse database, and the resultant intensity data were used to compare abundance of proteins across disease/control plasma pool. Results were analyzed with ingenuity pathways analysis. Right-tailed Fisher exact test was used to calculate a probability value.

RESULTS

Of 150 proteins that are common for both groups, ingenuity pathways analysis determined 105 proteins that were ready for analysis. Diseases and disorders analysis showed significant enrichment of proteins that are associated with cardiovascular disease. Within this cluster, the most abundant proteins were associated with vascular disease, atherosclerosis, and atherosclerotic lesions. Other top disease clusters were inflammatory response, organismal injury and abnormalities, and hematologic and metabolic disease.

CONCLUSION

Exposure to sFlt1-induced preeclampsia alters multiple biologic functions in mothers that persist later in life. Our results suggest that some of the long-term adverse outcomes that are associated with preeclampsia actually may be a consequence rather than a mere unmasking of an underlying predisposition. If similar results are found in humans, the development of preventive strategies for preeclampsia should also improve long-term maternal health.

Maternal plasma concentrations of angiogenic/antiangiogenic factors in the third trimester of pregnancy to identify the patient at risk for stillbirth at or near term and severe late preeclampsia

OBJECTIVE

To determine whether maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) at 30-34 weeks of gestation can identify patients at risk for stillbirth, late preeclampsia, and delivery of small-for-gestational-age (SGA) neonates.

STUDY DESIGN

A prospective cohort study included 1269 singleton pregnant women from whom blood samples were obtained at 30-34 weeks of gestation and who delivered at >34 weeks of gestation. Plasma concentrations of PlGF, sEng, and sVEGFR-1 were determined by enzyme-linked immunosorbent assay.

RESULTS

The prevalence of late (>34 weeks of gestation) preeclampsia, severe late preeclampsia, stillbirth, and SGA was 3.2% (n = 40), 1.8% (n = 23), 0.4% (n = 5), and 8.5% (n = 108), respectively. A plasma concentration of PlGF/sEng <0.3 MoM was associated with severe late preeclampsia (adjusted odds ratio, 16); the addition of PlGF/sEng to clinical risk factors increased the area under the receiver-operating characteristic curve from 0.76 to 0.88 (P = .03). The ratio of PlGF/sEng or PlGF/sVEGFR-1 in the third trimester outperformed those obtained in the first or second trimester and uterine artery Doppler velocimetry at 20-25 weeks of gestation for the prediction of severe late preeclampsia (comparison of areas under the receiver-operating characteristic curve; each P ≤ .02). Both PlGF/sEng and PlGF/sVEGFR-1 ratios achieved a sensitivity of 74% with a fixed false-positive rate of 15% for the identification of severe late preeclampsia. A plasma concentration of PlGF/sVEGFR-1 <0.12 MoM at 30-34 weeks of gestation had a sensitivity of 80%, a specificity of 94%, and a likelihood ratio of a positive test of 14 for the identification of subsequent stillbirth. Similar findings (sensitivity 80%; specificity 93%) were observed in a separate case-control study.

CONCLUSION

Risk assessment for stillbirth and severe late preeclampsia in the third trimester is possible with the determination of maternal plasma concentrations of angiogenic and antiangiogenic factors at 30-34 weeks of gestation.

Pregnancy-specific glycoproteins bind integrin αIIbβ3 and inhibit the platelet-fibrinogen interaction

Pregnancy-specific glycoproteins (PSGs) are immunoglobulin superfamily members encoded by multigene families in rodents and primates. In human pregnancy, PSGs are secreted by the syncytiotrophoblast, a fetal tissue, and reach a concentration of up to 400 ug/ml in the maternal bloodstream at term. Human and mouse PSGs induce release of anti-inflammatory cytokines such as IL-10 and TGFβ1 from monocytes, macrophages, and other cell types, suggesting an immunoregulatory function. RGD tri-peptide motifs in the majority of human PSGs suggest that they may function like snake venom disintegrins, which bind integrins and inhibit interactions with ligands. We noted that human PSG1 has a KGD, rather than an RGD motif. The presence of a KGD in barbourin, a platelet integrin αIIbβ3 antagonist found in snake venom, suggested that PSG1 may be a selective αIIbβ3 ligand. Here we show that human PSG1 binds αIIbβ3 and inhibits the platelet – fibrinogen interaction. Unexpectedly, however, the KGD is not critical as multiple PSG1 domains independently bind and inhibit αIIbβ3 function. Human PSG9 and mouse Psg23 are also inhibitory suggesting conservation of this function across primate and rodent PSG families. Our results suggest that in species with haemochorial placentation, in which maternal blood is in direct contact with fetal trophoblast, the high expression level of PSGs reflects a requirement to antagonise abundant (3 mg/ml) fibrinogen in the maternal circulation, which may be necessary to prevent platelet aggregation and thrombosis in the prothrombotic maternal environment of pregnancy.

Perfusion with magnesium sulfate increases sFlt-1 secretion only in the fetal side of placenta of women with preeclampsia

OBJECTIVE

To examine the effect of magnesium sulfate (MgSO(4)) on sFlt (soluble fms-like tyrosine kinase)-1 in the fetal and maternal compartments of normotensive and preeclamptic placentas.

METHODS

Cotyledons of term normotensive and preeclamptic placentas were dually perfused for six hours, with control medium and MgSO(4) (6-7 mg %) in the maternal reservoir. Perfusate sFlt-1 concentrations were measured.

RESULTS

Median sFlt-1 concentration was higher in the maternal than in the fetal side in both groups and perfusion media (p < 0.0001). When perfused with control medium, the maternal side median sFlt-1 concentration was higher in the preeclampsia than in the control group (p < 0.0001). After perfusion with MgSO(4), the median maternal and fetal sides perfusate sFlt-1 concentration were higher in the preeclampsia than in the control group (p < 0.0001). In comparison to perfusion with control medium, the median sFlt-1 concentration of normal pregnant women decreased in the fetal and increased in the maternal side. In the preeclampsia group, only median fetal side sFlt-1 concentration increased.

CONCLUSION

In contrast to normal pregnant women, perfusion with MgSO(4) of preeclamptic placentas did not increase their sFlt-1 concentration. This may indicate that MgSO(4) role may be limited to its anti-eclamptic and does not affect the anti-angiogenic state associated with preeclampsia.

Physiological changes in hematological parameters during pregnancy

Pregnancy is a state characterized by many physiological hematological changes, which may appear to be pathological in the non-pregnant state. The review highlights most of these changes along with the scientific basis for the same, as per the current knowledge, with a special reference to the red blood and white blood cells, platelets and hemostatic profile.

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.

ADAMTS13, FVIII, von Willebrand factor, ABO blood group assessment in preeclampsia

INTRODUCTION

Preeclampsia (PE) is a multifactorial disease characterized by high blood pressure and proteinuria after the 20th week of pregnancy. PE is associated with fibrin deposition in placental microcirculation and intrauterine fetal growth retardation. We evaluated FVIII activity, VWF and ADAMTS13 plasma levels, according to O and "non O" blood groups, in women with severe PE (sPE).

METHODS

This case-control study included 140 women; 55 pregnant with sPE, 35 normotensive pregnant and 50 non-pregnant women. VWF and ADAMTS13 antigen levels were assessed by ELISA (American Diagnostica). FVIII activity was measured by automated coagulometric method (Dade Behring) and ABO blood groups phenotyping was performed by indirect technique.

RESULTS

FVIII activity and VWF levels were significantly higher comparing either sPE to normotensive pregnant (P=0.01; P=0.05) and to non-pregnant women (P=0.00 in both cases) or normotensive pregnant and non-pregnant women (P=0.00 in both cases). A significant decrease in ADAMTS13 levels was observed comparing either sPE to normotensive pregnant (P=0.02) and non-pregnant women (P=0.00) or normotensive pregnant and non-pregnant women (P=0.00). FVIII activity and VWF levels were associated to O and "non O" blood groups only in non-pregnant women.

CONCLUSIONS

The increase of FVIII activity and VWF levels and the decrease of ADAMTS13 in sPE are not associated to O and "non O" blood groups. These alterations in hemostatic markers in sPE largely surpass those physiologically determined by ABO blood groups influence and may have masked the effect of O and "non O" groups in this disease. A concomitant analysis of VWF levels and ADAMTS13 activity and antigenic levels will be important to clarify the imbalance between these parameters found in sPE in the present study.

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.