Thrombophilia and the Risk for Venous Thromboembolism during Pregnancy, Delivery, and Puerperium

Prior Thromboembolic Disease and Assisted Reproductive Therapy

Assisted reproductive therapy (ART) increases the risk of venous thrombosis (VT) by 2- to 4-fold, whereas pregnancy increases the risk by 5- to 10-fold. Women with a history of VT undergoing ART are often suggested thromboprophylaxis. The literature is scarce and international guidelines are lacking. We made a review of the literature and base our suggestions primarily on expert opinions. We suggest women with a prior VT to use low-molecular-weight heparin as thromboprophylaxis starting from ovarian stimulation, throughout pregnancy, and 6 weeks postpartum. Assessment of VT risk should be done prior to ART. Adjustment of treatment to minimize the thrombotic risk, such as preventing ovarian hyperstimulation syndrome, single-embryo transfer, cryopreservation, and transfer of frozen embryos instead of fresh embryo in high-risk women, is suggested. Women with previous arterial thrombosis should continue aspirin during ART treatment, pregnancy, and postpartum.

Pregnancy-related venous thromboembolism and HIV infection

OBJECTIVE

To assess risk factors for venous thromboembolism (VTE) in African women in order to guide thromboprophylaxis.

METHODS

A case-control study was performed at a specialist obstetric unit in South Africa from July 1, 2017 to June 30, 2020. We identified 128 cases with VTE and 640 controls, matched for gestation.

RESULTS

Prepartum risk factors associated with VTE included; medical comorbidities (odds ratios [OR] 5.32, 95% confidence intervals [CI] 1.82-15.56), human immunodeficiency virus (HIV) (OR 2.84, 95% CI 1.50-5.41), and hospital admission or immobility (OR 5.33, 95% CI 1.17-24.22). Postpartum, the following were identified as significant risk factors; medical comorbidities (OR 23.72, 95% CI 8.75-64.27), hospital admission or immobility (OR 13.18, 95% CI 5.04-34.49), systemic infection (OR 4.48, 95% CI 1.28-15.68), HIV (OR 3.20, 95% CI 1.49-6.87), pre-eclampsia and fetal growth restriction (OR 2.74, 95% CI 1.18-6.36), and postpartum hemorrhage (OR 4.38, 95% CI 1.75-10.97). Antiretroviral therapy, opportunistic infections, and viral load >50 copies/ml, however, were not associated with VTE risk among HIV-infected participants.

CONCLUSION

HIV was a significant risk factor for pregnancy-related thrombosis. This was independent of traditional HIV risk factors. As such, future studies are recommended to explore the mechanisms of thrombosis associated with HIV infection.

The Correlation Between Abnormal Uterine Artery Flow in the First Trimester and Genetic Thrombophilic Alteration: A Prospective Case-Controlled Pilot Study

INTRODUCTION

Evaluation of the first trimester uterine artery flow can predict the development of obstetrical complications. A genotype, making women prone to microthrombi. constitutes the main known susceptibility factor for anomalous development of placenta. Our aim was to study whether polymorphisms of 10 genes leading to blood clotting abnormalities are related to abnormal uterine artery blood flow in the first trimester, and may predict placenta-related diseases.

MATERIAL AND METHODS

In primary analyses we included 19 singleton pregnancies with abnormal blood flow in the uterine arteries during the first trimester of gestation, and 24 matched control with normal flow patterns. All patients were genotyped for sequence variations in F5, F2, F11, MTHFR, SERPINE-1, CYP4V2, SELE, GP6, angiotensinogen (AGT) and fibrinogen gamma (FGG) genes and followed up until delivery.

RESULTS

There were no differences between groups regarding selected sequence variations in any of these genes. The co-occurrence of several polymorphisms in the same patient was also not related to the blood flow patterns in the uterine arteries.

CONCLUSIONS

Although we found certain trends of genetic polymorphisms being related to preeclampsia and fetal growth, we failed to find an association between clotting gene polymorphisms, single or in combination, with the abnormal uterine flow in the first trimester.

United Kingdom recommendations for obstetric venous thromboembolism prophylaxis: Evidence and rationale

Venous thromboembolism (VTE) is a leading cause of maternal death in the United Kingdom. To address this problem guidance from the Royal College of Obstetricians and Gynaecologists (RCOG) has been developed that recommends the assessment of a woman's risk of thrombosis at specific time-points during pregnancy and postnatally at the time of delivery. The RCOG guidelines provide clinicians with a framework to inform decision-making on the use of thromboprophylaxis and are based on the premise that the higher risk a woman has for VTE, the more likely she is to benefit from prophylaxis - determining her level of risk is based on the number and characteristics of the risk factors that she has. This article will address the pathophysiology of VTE in pregnancy, evidence behind the risk factors for VTE and the use of thromboprophylactic agents. Further, it will reflect on the rationale behind the RCOG guidance.

Contemporary management of patients with BCR-ABL1-negative myeloproliferative neoplasms during pregnancy

INTRODUCTION

The management of pregnancy during the course of BCR-ABL1-negative myeloproliferative neoplasms (MPN) is an increasingly relevant problem. This is mostly due to earlier and better diagnosis of MPN together with the trend in modern society toward delaying pregnancy until later life. Areas Covered: The present review aims to provide an overview of the available literature data concerning outcome of pregnancy in MPN. Possible therapeutic modalities are discussed and a management algorithm is suggested. Expert Commentary: Most data are available for women with essential thrombocythemia and we present 793 published pregnancies. Live birth rate is 68.5% with 31.5% miscarriages. Spontaneous abortion is the most frequent complication with 26.5%, followed by stillbirth with 4.8%. Maternal complications are relatively low with 1.8% major thrombotic and 2.4% major bleeding events. In polycythemia vera the situation is clinically more complex and roughly 150 pregnancy reports are available. There is very limited information in primary myelofibrosis with less than 20 reported pregnancies. With active management including control of blood counts, aspirin, low molecular weight heparin and in higher risk cases interferon alpha pregnancy in MPN is manageable with a success rate not far below the normal situation with 80%.

Surgical management of iliofemoral vein thrombosis during pregnancy and the puerperium

BACKGROUND

The risk of deep venous thrombosis is elevated during pregnancy and the puerperium. Therapy is usually limited to conservative measures as invasive thrombus removal is feared because of possible complications. However, leg- or life-threatening situations require fast thrombus removal, and the long-term rate of post-thrombotic syndrome (PTS) may be reduced by venous recanalization. Our center's experience may give support to surgical venous thrombectomy (VT).

METHODS

Between 1996 and 2016, all women who received VT for pregnancy-related deep venous thrombosis in our department were included. Retrospective data were combined with a current follow-up.

RESULTS

The study included 82 women with a mean age of 29 years (17-38 years). An additional arteriovenous fistula was performed in 79 and planned simultaneous cesarean section in 13 patients. Neither pulmonary emboli nor fetal complications occurred during surgery, and perioperative and postoperative mortality was 0%. Operative revision was required in 38% mainly for rethrombosis (24%) and bleeding (12%). One fetus died 2 months after VT of unrelated causes. After a mean of 83 months, complete venous recanalization was seen in 88%, venous valve sufficiency in 90%, and PTS in 31% without any ulcers. At 10 years, PTS incidence rose to reach 50% with limited statistical significance because of the number of patients reaching long-term follow-up.

CONCLUSIONS

Iliofemoral venous recanalization during pregnancy can be performed safely in a specialized center, with lower PTS rates than in historical controls.

Prevalence of Budd-Chiari Syndrome during Pregnancy or Puerperium: A Systematic Review and Meta-Analysis

Women during pregnancy or puerperium are likely to develop Budd-Chiari syndrome (BCS). However, the reported prevalence of pregnancy-related BCS varied considerably among studies. Our study aims to systematically review this issue. Overall, 817 papers were initially identified via the PubMed, EMBASE, China National Knowledge Infrastructure, and Chinese Scientific and Technological Journal databases. Twenty of them were eligible. The prevalence of pregnancy-related BCS varied from 0% to 21.5%. The pooled prevalence was 6.8% (95% CI: 3.9–10.5%) in all BCS patients, 6.3% (95% CI: 3.8–9.4%) in primary BCS patients, and 13.1% (95% CI: 7.1–20.7%) in female BCS patients. Among them, one study was carried out in Africa with a prevalence of 10.6%; 14 studies in Asian countries with a pooled prevalence of 7.1% (95% CI: 3.1–12.6%); and 5 studies in European countries with a pooled prevalence of 5.0% (95% CI: 3.1–7.3%). The pooled prevalence was 6.7% (95% CI: 2.6–12.3%) in studies published before 2005 and 7.3% (95% CI: 4.2–12.5%) in those published after 2005. In conclusion, pregnancy is a relatively common risk factor for BCS, but there is a huge variation in the prevalence among studies. Physicians should be aware of pregnancy-related BCS.

Diagnostik und Therapie venöser Thromboembolien in der Schwangerschaft und Postpartalperiode

Das Auftreten sowohl der tiefen Beinvenenthrombose als auch einer Lungenarterienembolie wird bereits durch physiologische Mechanismen in der Schwangerschaft und im Wochenbett begünstigt. Es kommt neben vorbestehenden Risikofaktoren zu transienten Erscheinungen, die das Risiko für venöse thromboembolische Erkrankungen erhöhen. Die Klinik von Thromboembolien ist oft unspezifisch. Erprobte Diagnosealgorithmen bestehen in der Schwangerschaft nicht. Aufgrund der klinischen Relevanz ist jedoch eine Diagnosesicherung unerlässlich. Die Anamnese, Klinik und Labordiagnostik sind wesentliche Bestandteile in der Diagnosefin-dung, können aber alleine eine venöse Thromboembolie nicht ausschließen. Eine apparative Beurteilung der betroffenen Venen durch die Sonographie ist dabei die Untersuchungsmethode der Wahl. Die vorliegende Arbeit beschreibt die Diagnostik und Therapie venöser Thromboembolien in der Schwangerschaft.

[Antithrombotic therapy and pregnancy]

The incidence of venous thromboembolism (VTE) during pregnancy is about one event per 1000 pregnancies and placenta-mediated pregnancy complications (PC) occurred in 15%. Knowing the biological combined with clinical risk factors would help to prevent problems during the pregnancy. Several antithrombotic therapies exist, including very recent ones but LMWH and aspirin are still molecules of choice. The women should be assessed for VTE and PC risk in order to improve the outcome.

Venous thromboembolism in pregnancy

In Western nations, venous thromboembolism (VTE) is an important cause of morbidity and the most common cause of maternal death during pregnancy and the puerperium. Pregnancy is a hypercoagulable state in which coagulation is activated and thrombolysis inhibited. This prothrombotic risk is compounded when hereditary and acquired thrombophilias and other prothrombotic risk factors are present. The risk of venous thrombotic events is increased fivefold during pregnancy and 60-fold in the first 3 months after delivery (postpartum period) compared with nonpregnant women. Many of the signs and symptoms of VTE overlap those of a normal pregnancy, which complicates the diagnosis. Patients with history of previous VTE should use graduated compression stockings throughout pregnancy and the puerperium, and should receive postpartum anticoagulant prophylaxis. The indications for antepartum anticoagulant prophylaxis are somewhat controversial. This article reviews the management of VTE during pregnancy and in the postpartum period.

Risk of venous thrombosis in pregnancy among carriers of the factor V Leiden and the prothrombin gene G20210A polymorphisms

BACKGROUND

Pregnancy is associated with a 10-fold increased risk of venous thrombosis (VT), with different risk profiles for the antenatal and postnatal periods. The purpose of this study was to assess the risk of pregnancy-related VT associated with the factor (F)V Leiden and prothrombin gene G20210A polymorphisms.

MATERIALS AND METHODS

The study comprised 377,155 women with 613,232 pregnancies at 18 Norwegian hospitals from 1 January 1990 to 31 December 2003. Of a total 559 cases with a validated first lifetime diagnosis of VT in pregnancy or within 14 weeks postpartum, and 1229 controls naive for VT, 313 cases and 353 controls donated biological material.

RESULTS

The odds ratios for VT during pregnancy or puerperium were 5.0 [95% confidence interval (CI) 3.1-8.3] and 9.4 (95% CI 2.1-42.4) for heterozygous carriers of the FV Leiden and the prothrombin gene polymorphisms, respectively. All homozygous carriers of the FV Leiden polymorphism (n = 8) and the prothrombin polymorphism (n = 1) developed VT, indicating a very high risk of VT. We estimated that pregnancy-related VT occurred in 1.1/1000 non-carriers, in 5.4/1000 heterozygous carriers of the FV Leiden polymorphism, and in 9.4/1000 heterozygous carriers of the prothrombin polymorphism. To avoid one VT, the number of pregnant women needed to be screened for these two polymorphisms and the number needed to be given thromboprophylaxis were 2015 and 157, respectively.

CONCLUSIONS

Although the relative risk for VT during pregnancy and after delivery was increased among carriers of the FV Leiden and the prothrombin polymorphisms, the overall probability for pregnancy-related VT was low.

Deep vein thrombosis and pulmonary embolism in pregnancy: diagnosis, complications, and management

Venous thromboembolism is a leading cause for maternal mortality. Because of the increase risk for thromboembolism in pregnancy and the postpartum period, the clinician must be on high alert for the signs and symptoms and use appropriate diagnostics in a timely manner so that prompt anticoagulation therapy can be initiated. A diagnostic and management approach for both deep vein thrombosis and pulmonary embolism and for prophylaxis against thromboembolism in the obstetric patient are crucial to decreasing morbidity, mortality, and long-term sequelae.

The association of antiphospholipid antibodies with pregnancy-related first time venous thrombosis--a population-based case-control study

In this population-based case-control study we explored the association of antiphospholipid antibodies with pregnancy-related venous thrombosis. From 1990 through 2003 615 pregnant women were identified at 18 hospitals in Norway with a diagnosis of first time VT. In 2006, 531 of 559 eligible cases and 1092 of 1229 eligible controls were invited for further investigations. The final study population comprised 313 cases and 353 controls, who completed a comprehensive questionnaire and donated a single blood sample, 3-16 years after index pregnancy. We report the results on lupus anticoagulant, anticardiolipin antibodies, and anti-ss(2) glycoprotein-1 antibodies alone, in combination, and with the contribution of the factor V Leiden and the prothrombin gene G20210A polymorphisms. Cut-off values for APAs were chosen according to current international consensus. 29 (9.3%) of the cases and 24 (6.8%) of the controls had at least one positive test for APAs (OR 1.4; 95% CI 0.8-2.5). Nine cases (2.8%) and no controls had more than one positive test (multi-positivity) for APAs. After excluding women with factor V Leiden or prothrombin polymorphisms, still 6 cases were multi-positive for APAs. We conclude that multi-positivity, but not single-positivity, for APAs was weakly associated with a history of ante- and postnatal VT.

Venous thromboembolism in women

Abstract

The risk of venous thromboembolism (VTE) varies throughout a woman’s life and is associated primarily with underlying hormonal exposure. Alteration in hemostatic mechanisms, including resistance to activated protein C, may explain this altered risk. Initially, development of VTE with the use of contraception in young adulthood may reveal inherited thrombophilia. Pregnancy, and particularly the post-partum period, likely confer the greatest risk of VTE, but the absolute risk is small. Guidelines for prevention of VTE during pregnancy are based on personal or family history of VTE, and known inherited thrombophilia. Use of hormone replacement therapy later in life is associated with increased risk of VTE, and may be safest if given as an estrogen-only preparation to young postmenopausal women for less than 5 years. Universal screening for thrombophilia prior to pregnancy or initiating hormonal therapy is not recommended; however, selected testing in high-risk groups may be warranted. The lack of firm recommendations for the prevention of VTE in women highlights the need for future investigation aimed at identifying high-risk groups and evaluating the efficacy of prophylactic measures.

Management of Philadelphia negative chronic myeloproliferative disorders in pregnancy

The management of pregnancy in Philadelphia negative chronic myeloproliferative disorders (CMPDs) is an increasingly frequent problem. In the literature, most pregnancies are reported for women with essential thrombocythemia (ET) with about 400 pregnancies in about 200 women. In ET, first trimester abortion is the most frequent complication occurring in about one third of pregnancies. Interestingly, the incidence of maternal complications is relatively low with 3% for major thromboembolic and 2% for major bleeding events. The presence of the Jak2 mutation seems to be an independent predictor of pregnancy complications. Pregnancies in ET should be stratified according to underlying risk factors in low, high and highest risk pregnancies. Women with low risk pregnancies are treated with low-dose aspirin, whereas women with high and higher risk pregnancies may benefit from low-dose aspirin plus interferon alpha +/- low molecular weight heparin throughout pregnancy and at least for six weeks post-partum. In polycythemia vera (PV) there is only very few information on pregnancy outcome with 36 pregnancies reported in the literature. According to these data pregnancy in PV is per se a high risk situation. Accordingly, all women with PV should be treated with low-dose aspirin. Some pregnant PV patients may benefit from a more intensive therapy including interferon alpha +/- low molecular weight heparin throughout pregnancy and at least for six weeks post-partum.