Thrombophilia and adverse pregnancy outcome

Redox status of pregnant women with thrombophilia

Background/Aim. Since the role of oxidative stress in the pathogenesis of thrombophilia in pregnancy has still not been clarified, the aim of the study was to assess the redox status of pregnant women with thrombophilia. Methods. The study involved 120 pregnant women divided into two groups: pregnant women with thrombophilia (n = 60) and women with normal pregnancy (n = 60). Blood samples for biochemical analysis were collected at the end of the first, second, and third trimester of pregnancy. Concentrations of hydrogen peroxide (H2O2), nitrites (NO2-), and the index of lipid peroxidation measured as thiobarbituric acid reactive substances (TBARS) were measured in plasma. Levels of reduced glutathione (GSH), activities of superoxide dismutase (SOD) and catalase (CAT) were measured in erythrocytes. Results. In women with thrombophilia, NO2- values were increased in the first and third trimester compared to healthy pregnant women (p < 0.05). The higher levels of TBARS and H2O2 were noticed in women with thrombophilia in the first trimester compared to healthy pregnant women (p < 0.05). The values of SOD and CAT were lower in women with thrombophilia in the third and GSH in the first trimester compared to the control group (p < 0.05). Conclusion. Our results suggest an increased generation of prooxidants in thrombophilia at the beginning of gestation, which declines as gestation progresses and reaches similar values as in normal pregnancy at the end of pregnancy. Generally viewed, pregnant women with thrombophilia was associated with impaired antioxidant capacity ? activities of SOD and CAT were lower in the third and GSH in the first trimester compared to their values in healthy pregnant women.

Genetic risk assessment of thrombophilia in patients with adverse obstetric outcomes

OBJECTIVES

To investigate the incidence of inherited thrombophilias in patients with adverse obstetric outcomes and to compare detection rates of thrombophilias between standard blood tests and a novel genetic test.

METHODS

This is a case-control prospective study performed in Hospital Sant Joan de Déu in Barcelona, Spain. Cases had a history of intrauterine growth restriction requiring delivery before 34 weeks gestation, placental abruption before 34 weeks gestation, or severe preeclampsia. Controls had at least two normal, spontaneously conceived pregnancies at term, without complications or no underlying medical disease. At least 3 months after delivery, all case and control women underwent blood collection for standard blood tests for thrombophilias and saliva collection for the genetic test, which enables the diagnosis of 12 hereditary thrombophilias by analyzing genetic variants affecting different points of the blood coagulation cascade.

RESULTS

The study included 33 cases and 41 controls. There were no statistically significant differences between cases and controls in the standard blood tests for thrombophilias in plasma or the TiC test for genetic variables. One clinical-genetic model was generated using variables with the lowest P values: ABO, body mass index, C_rs5985, C_rs6025, and protein S. This model exhibited good prediction capacity, with an area under the curve of almost 0.7 (P <0.05), sensitivity of almost 67%, and specificity of 70%.

CONCLUSION

Although some association may exist between hypercoagulability and pregnancy outcomes, no significant direct correlation was observed between adverse obstetric outcomes and inherited thrombophilias when analyzed using either standard blood tests or the genetic test. Future studies with a larger sample size are required to create a clinical-genetic model that better discriminates women with a history of adverse pregnancy outcomes and an increased risk of poor outcomes in subsequent pregnancies.

Comprehensive Evaluation of the Effectiveness and Safety of Placenta-Targeted Drug Delivery Using Three Complementary Methods

No effective treatments currently exist for placenta-associated pregnancy complications, and developing strategies for the targeted delivery of drugs to the placenta while minimizing fetal and maternal side effects remains challenging. Targeted nanoparticle carriers provide new opportunities to treat placental disorders. We recently demonstrated that a synthetic placental chondroitin sulfate A binding peptide (plCSA-BP) could be used to guide nanoparticles to deliver drugs to the placenta. In this protocol, we describe in detail a system for assessing the efficiency of drug delivery to the placenta by plCSA-BP that employs three separate methods used in combination: in vivo imaging, high-frequency ultrasound (HFUS), and high-performance liquid chromatography (HPLC). Using in vivo imaging, plCSA-BP-guided nanoparticles were visualized in the placentas of live animals, while HFUS and HPLC demonstrated that plCSA-BP-conjugated nanoparticles efficiently and specifically delivered methotrexate to the placenta. Thus, a combination of these methods can be used as an effective tool for the targeted delivery of drugs to the placenta and development of new treatment strategies for several pregnancy complications.

Abnormal inflammation leads to maternal coagulopathies associated with placental haemostatic alterations in a rat model of foetal loss

Spontaneous pregnancy loss is often associated with aberrant maternal inflammation and systemic coagulopathies. However, the role of inflammation in the development of obstetric coagulopathies is poorly understood. Further, questions remain as to whether systemic coagulopathies are linked to placental haemostatic alterations, and whether these local alterations contribute to a negative foetal outcome. Using a model of spontaneous foetal loss in which pregnant rats are given a single injection of bacterial lipopolysaccharide (LPS), we characterised the systemic maternal coagulation status following LPS administration using thromboelastography (TEG), a global haemostatic assay that measures the kinetics of clot formation. Systemic maternal coagulopathy was evident in 82% of LPS-treated rats. Specifically, we observed stage-I, -II, and -III disseminated intravascular coagulation (DIC) and hypercoagulability. Modulation of inflammation through inhibition of tumour necrosis factor α with etanercept resulted in a 62% reduction in the proportion of rats exhibiting coagulopathy. Moreover, inflammation-induced systemic coagulopathies were associated with placental haemostatic alterations, which included increased intravascular, decidual, and labyrinth fibrin deposition in cases of DIC-I and hypercoagulability, and an almost complete absence of fibrin deposition in cases of DIC-III. Furthermore, systemic and placental haemostatic alterations were associated with impaired utero-placental haemodynamics, and inhibition of these haemostatic alterations by etanercept was associated with maintenance of utero-placental haemodynamics. These findings indicate that modulation of maternal inflammation may be useful in the prevention of coagulopathies associated with complications of pregnancy.

Microparticles and pregnancy complications

Microparticles (MPs) are shed from cell membranes of a variety of cells, promote thrombus formation, mediate pro-inflammatory effects and may cause endothelial dysfunction. Normal pregnancy is characterized by increased levels of MPs compared to non-pregnant healthy women but the prevalence, cell origin and the role of MPs in pregnancy-related complications remain controversial. Normal pregnancy is an acquired hyper-coagulable state due to an increase in procoagulants and decrease in natural anticoagulants. Pregnancy-related complications such as preeclampsia, intrauterine fetal growth restriction (IUGR) and fetal loss are associated with placental dysfunction and may cause significant maternal and fetal morbidity and mortality. This article highlights the role of microparticles in maternal placental crosstalk and the interplay between microparticles, thrombosis and pregnancy complications.

Favorable maternal and fetal effects of danshensu in an experimental mice model of preeclampsia

BACKGROUND

Preeclampsia is a serious pregnancy-specific complication that results in high maternal and neonatal mortality and morbidity worldwide. Till date, there is no satisfactory pharmacotherapeutic treatment, except for aspirin and heparin, to stop the preeclampsia progression. Although the mechanism of preeclampsia is poorly understood, it has proved to be associated with coagulation activation. Researches on prophylactic and remedial application of anticoagulants maybe benefit the clinical aspects of preeclampsia individuals.

METHODS

Sixty-six preeclampsia-like pregnant mice, induced by phosphatidyleserine/phosphatidylcholine (PS/PC) microvesicle administration, were randomly divided into six groups as follows: control group (group C), preeclampsia model group (group PE), group treated with heparin (group H), group treated with aspirin (group A), group treated with low-dose danshensu (group LD), and group treated with high-dose danshensu (group HD). Systolic blood pressure (SBP), proteinuria, mean platelet counts, plasma antithrombin III activity (AT III), D-dimmer levels, thrombin time (TT), fibrin deposition with phosphotungstic acid hematoxylin (PTAH) staining, and thrombomodulin (TM) expression with immunohistochemistry staining in placentas were examined as indices for maternal syndrome. Meanwhile, the number of potentially viable fetuses, weight of fetuses and placentas, weight of fetal brains, nose-breech length, ponderal index (PI), and neurons with hematoxylin-eosin (H/E) and toluidine blue-eosin (Nissl's) staining were all evaluated as indices for fetal syndrome.

RESULTS

Heparin presents significant effects on maternal syndrome of preeclampsia such as hypertension and proteinuria, and different dose danshensu also presents the certain effects. High-dose danshensu and aspirin all process better effects than low-dose danshensu on decreasing blood pressure to normal level, whereas high-dose danshensu process better effects than aspirin and low-dose danshensu on decreasing proteinuria to normal level. As to danshensu's effects on hemostatic function, high- and low-dose danshensu's marked effects on increasing the plasma AT III activity are same as that of aspirin and inferior to heparin. High-dose danshensu's better effect on elevating the platelet counts is superior to low-dose danshensu and aspirin. Low-dose danshensu's obvious effect on decreasing D-dimmer levels is close to heparin and superior to high-dose danshensu and aspirin. High- and low-dose danshensu's significant effects on reduced TT level are same to that of heparin. Different anticoagulants all have the improvement roles on placental fibrin depositions, but heparin and high-dose danshensu's roles on lowering thrombomodulin expression in placentas are superior to low-dose danshensu and aspirin. But anticoagulant function of high-dose danshensu is still inferior to heparin. Furthermore, we found the following changes: increasing fetal body weight and length in every group, obvious overall improvement in group H, greater amelioration equaling to that in heparin group on maternal body weight, fetal nose-breech length and fetal brain weight in group HD, better changes on survival fetal number in group LD than in other groups, and more corrected brain development in group HD than in group A. We found long-term use of heparin and aspirin, in spite of low-dose administration, can raise the risk of bleeding such as placental abruption and intestinal hemorrhage. But no side effect was observed in mice treated with different dose of danshensu in our study.

CONCLUSIONS

Danshensu has proven effective in ameliorating the prognosis of maternal syndrome and fetal syndrome in the PE mouse model. We suggest long-term provision of low-dose danshensu in pregnancy, leading to an improvement of preeclampsia syndrome with considerable maternal safety.

Thrombophilia mediates lowering cardiovascular risk factors in women with a history of preeclampsia

OBJECTIVE

Preeclampsia is associated with increased risk of cardiovascular disease. The aim of this pilot study was to assess whether the presence of thrombophilia results in a greater tendency to develop endothelial dysfunction and cardiovascular diseases.

METHODS

Ten women with thrombophilia were matched with 10 women without thrombophilia for a history of hypertensive disorders during pregnancy. Laboratory measurements: blood pressure, insulin sensitivity, and micro- and macrovascular function were determined.

RESULTS

Women with thrombophilia had significant lower total- and low-density cholesterol, were more insulin sensitive, and had better microvascular function.

CONCLUSION

This study suggests that thrombophilia "mediates" in lowering of cardiovascular risk factors in women with a history of preeclampsia.

Pravastatin prevents miscarriages in mice: role of tissue factor in placental and fetal injury

Pregnancy loss and intrauterine growth restriction (IUGR) are serious pregnancy complications, and the triggers and mediators of placental and fetal damage are not completely understood. Using a mouse model of recurrent spontaneous miscarriages (DBA/2-mated CBA/J mice) that shares features with human recurrent miscarriage and fetal growth restriction, we identified tissue factor (TF) as an essential participating factor in placental and fetal injury. We have previously shown that C5a releases antiangiogenic molecule sFlt-1 in monocytes that causes defective placental development and fetal death in DBA/2-mated CBA/J mice. In this study, we found that TF not only activates the coagulation pathway, but it also mediates sFlt-1 release in monocytes causing defective placental development and fetal death. Blockade of TF with a monoclonal antibody inhibited sFlt-1 release, prevented the pathological activation of the coagulation pathway, restored placental blood flow, prevented placental oxidative stress, and rescued pregnancies. We also demonstrated that pravastatin, by down-regulating TF expression on monocytes and trophoblasts, prevented placental damage and protected pregnancies in DBA/2-mated CBA/J mice. These studies indicate that TF is an important mediator in fetal death and growth restriction and that statins may be a good treatment for women with recurrent miscarriages and IUGR.

FV-Leiden- und Prothrombin-G20210A-Mutation

Die Faktor-V-Leiden-Mutation und die Prothrombin-G20210A-Mutation sind mit einer Inzidenz von 2–4% und etwa 1% die häufigsten genetisch determinierten thrombophilen Risikofaktoren. Während der thrombophile Mechanismus der FV-Leiden-Mutation auf einer Hemmung der antikoagulatorischen Aktivität von aktiviertem Protein C (APC) beruht, ist der molekulare Mechanismus der Prothrombin-G20210A-Mutation nicht eindeutig geklärt. Das Vorliegen beider Mutationen erhöht das Risiko für eine venöse Thrombose, hat aber keinen wesentlichen Einfluss auf das Rezidivrisiko nach einer spontanen venösen Thrombose. Deswegen kann der Mutationsnachweis die klinische Diagnose einer Thrombophilie zwar bestätigen, beeinflusst aber – bis auf homozygote und compound-heterozygote Mutationsträger – das therapeutische Vorgehen nicht.