Treatment of deep venous thrombosis with low-molecular-weight heparin during pregnancy

Efficacy and safety of postural intervention on prevention of deep venous thrombosis of lower extremity in postpartum women with pregnancy-induced hypertension: A protocol for systematic review and meta-analysis

BACKGROUND

Deep venous thrombosis (DVT) is a relatively serious complication commonly seen in pregnant women, especially parturients with pregnancy-induced hypertension (PIH), whose incidence of DVT is higher. Because it can lead to pulmonary embolism (PE) and endanger the lives of patients, it has been paid much attention in clinic. Nursing plays an important role in the prevention and treatment of DVT. Early posture intervention can prevent postpartum DVT in hypertensive pregnant women, which has certain clinical value, but there is no evidence of evidence-based medicine. This study aims to systematically study the effectiveness and safety of postural intervention on prevention of deep venous thrombosis of lower extremity in postpartum women with PIH.

METHODS

Use the computer to retrieve the English databases (PubMed, Embase, Web of Science, the Cochrane Library) and the Chinese databases (China Knowledge Network, Wanfang, Weipu, China Biomedical Database), in addition to the manual retrieval of Baidu academic, Google academic, from the construction of database to December 2020, for randomized controlled clinical studies of postural intervention on prevention of deep venous thrombosis of lower extremity in postpartum women with PIH. Two researchers independently extracted the data and evaluated the quality of the included research, and used RevMan5.3 software to do meta-analyze of the included literature.

RESULTS

This study assessed the efficacy and safety of potential intervention on prevention of deep venous thrombosis of lower extremities with lower extremity hypertension by mean velocity of femoral venous flow in the lower extremities, lower extremity skin status, swelling level, and pain condition, lower extremity deep venous thrombosis rate, and incidence of pulmonary embolism.

CONCLUSION

This study will provide reliable evidence-based evidence for the clinical application of postural intervention on prevention of deep venous of lower extremity in Postpartum women with PIH.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/4NPKW.

Evaluation of therapeutic efficacy of anticoagulant drugs for patients with venous thromboembolism during pregnancy: A systematic review and meta-analysis

A meta-analysis based on published literature was undertaken to evaluate the efficacy of anticoagulant drugs for the treatment of venous thromboembolism during pregnancy. PubMed, Cochrane and Embase databases were searched from inception to September 2018 for relevant studies using indexed words, including qualified case-control and cohort studies. The meta-analysis used odds ratios (OR) and 95% confidence intervals (95% CI) to analyse the primary results. Nine studies were included in this meta-analysis, with a total of 834 cases and 3424 controls. There were no significant differences in the incidence of prenatal haemorrhage (OR 1.08, 95% CI 0.84-1.40), venous thromboembolism (OR 1.30, 95% CI 0.72-2.33) or caesarean section (OR 1.16, 95% CI 0.69-1.98) between the case group and the control group. The incidence of pulmonary embolism was significantly higher in the case group than in the control group (OR 3.90, 95% CI 1.23-12.34). However, there were a few limitations that may have influenced the results, so more randomized double-blind controlled studies of high quality are warranted to confirm the efficacy of anticoagulant therapy for venous thromboembolism in pregnancy.

Obstetric venous thromboembolism: a systematic review of dalteparin and pregnancy

A systematic review of studies published between 1 January 1985 and 31 August 2017 was performed to analyse the efficacy of the low-molecular-weight heparin, dalteparin, in venous thromboembolism (VTE) treatment and prophylaxis during pregnancy, and to evaluate dosing practices, anticoagulant monitoring and adverse events. A therapeutic dosing throughout pregnancy or followed by reduced doses effectively prevented VTE recurrence. Anti-factor Xa activity was the most commonly used method of dose monitoring. The risk of bleeding with dalteparin was generally minor. Major bleeding was observed when a high dose of dalteparin was employed during (or close to) delivery, or postpartum. Other adverse events were minor. Disparity exists in VTE treatment and thromboprophylaxis, with wide variety in the dosing regimens, treatment strategies and monitoring practices employed. Large randomised controlled trials are warranted but due to ethical reasons, and the rarity of VTE-associated obstetric complications, case-control, registry and large observational studies present more likely options.

Management and treatment of deep vein thrombosis in special populations

INTRODUCTION

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is the third most frequent cardiovascular disease besides myocardial infarction and stroke. Because DVT may cause life-threatening conditions, treatment should be started as soon as possible. This comprises certain challenges in special populations. Areas covered: In cancer-associated VTE, current treatment is different from non-cancer VTE due to disease-related interventions and higher bleeding risks. In the treatment of patients with extensive DVT, the role of catheter-directed thrombolysis has been investigated in two randomized trials, but results do not yield a recommendation for standard thrombolysis. The diagnosis of suspected recurrent DVT is especially challenging in case of ipsilateral DVT. Treatment strategies in recurrent DVT are dependent on the case and on particular risk factors. Also discussed is the therapy for DVT in pregnant women, which is more complex as a result of anticoagulants crossing the placenta. Expert commentary: DVT treatment in special populations poses special challenges due to high thrombotic and bleeding risk. This will be discussed in more detail in this review.

Intermediate doses of low-molecular-weight heparin for the long-term treatment of pregnancy thromboembolism. A systematic review

Note: The contact information for Drs. Gandara and Carrier is the same as for Dr. Rodger. Their e-mail addresses are egandara@ohri.ca and mcarrier@ohri.ca, respectively.

Anticoagulant therapy for venous thromboembolism during pregnancy: a systematic review and a meta-analysis of the literature

Venous thromboembolism (VTE) is one of the most relevant causes of maternal death in industrialized countries. Low molecular weight heparin (LMWH), continued throughout the entire pregnancy and puerperium, is currently the preferred treatment for patients with acute VTE occurring during pregnancy. However, information on the efficacy and safety of anticoagulant drugs in this setting is extremely limited. We carried out a systematic review and a meta-analysis of the literature to provide an estimate of the risk of bleeding complications and VTE recurrence in patients with acute VTE during pregnancy treated with antithrombotic therapy. The weight mean incidence (WMI) of bleeding and thromboembolic events and the corresponding 95% confidence interval (CI) were calculated. Eighteen studies, giving a total of 981 pregnant patients with acute VTE, were included. LMWH was prescribed to 822 patients; the remainder were treated with unfractionated heparin. Anticoagulant therapy was associated with WMIs of major bleeding of 1.41% (95% CI 0.60-2.41%; I) antenatally and 1.90% (95% CI 0.80-3.60%) during the first 24 h after delivery. The estimated WMI of recurrent VTE during pregnancy was 1.97% (95% CI 0.88-3.49%; I(2) 39.5%). Anticoagulant therapy appears to be safe and effective for the treatment of pregnancy-related VTE, but the optimal dosing regimens remain uncertain.

Evaluating patient values and preferences for thromboprophylaxis decision making during pregnancy: a study protocol

BACKGROUND

Pregnant women with prior venous thromboembolism (VTE) are at risk of recurrence. Low molecular weight heparin (LWMH) reduces the risk of pregnancy-related VTE. LMWH prophylaxis is, however, inconvenient, uncomfortable, costly, medicalizes pregnancy, and may be associated with increased risks of obstetrical bleeding. Further, there is uncertainty in the estimates of both the baseline risk of pregnancy-related recurrent VTE and the effects of antepartum LMWH prophylaxis. The values and treatment preferences of pregnant women, crucial when making recommendations for prophylaxis, are currently unknown. The objective of this study is to address this gap in knowledge.

METHODS

We will perform a multi-center cross-sectional interview study in Canada, USA, Norway and Finland. The study population will consist of 100 women with a history of lower extremity deep vein thrombosis (DVT) or pulmonary embolism (PE), and who are either pregnant, planning pregnancy, or may in the future consider pregnancy (women between 18 and 45 years). We will exclude individuals who are on full dose anticoagulation or thromboprophylaxis, who have undergone surgical sterilization, or whose partners have undergone vasectomy. We will determine each participant's willingness to receive LMWH prophylaxis during pregnancy through direct choice exercises based on real life and hypothetical scenarios, preference-elicitation using a visual analog scale ("feeling thermometer"), and a probability trade-off exercise. The primary outcome will be the minimum reduction (threshold) in VTE risk at which women change from declining to accepting LMWH prophylaxis. We will explore possible determinants of this choice, including educational attainment, the characteristics of the women's prior VTE, and prior experience with LMWH. We will determine the utilities that women place on the burden of LMWH prophylaxis, pregnancy-related DVT, pregnancy-related PE and pregnancy-related hemorrhage. We will generate a "personalized decision analysis" using participants' utilities and their personalized risk of recurrent VTE as inputs to a decision analytic model. We will compare the personalized decision analysis to the participant's stated choice.

DISCUSSION

The preferences of pregnant women at risk of VTE with respect to the use of antithrombotic therapy remain unexplored. This research will provide explicit, quantitative expressions of women's valuations of health states related to recurrent VTE and its prevention with LMWH. This information will be crucial for both guideline developers and for clinicians.

Comparison of different dose regimens of enoxaparin in deep vein thrombosis therapy in pregnancy

INTRODUCTION

Pregnant women have a higher risk of developing deep vein thrombosis (DVT) and consequent thrombogenic events, including pulmonary embolisms. Low-molecular-weight heparin (LMWH) products have been shown to successfully treat DVT with few significant side effects. The purpose of this study was to compare the effects of two dose regimens of enoxaparin (a LMWH) in the management of DVT in pregnancy.

METHODS

A total of 35 pregnant patients with DVT were enrolled in this study. As first-line anticoagulation therapy, patients were administered an intravenous unfractionated heparin infusion for 5 days, followed by a subcutaneous injection of enoxaparin 1 mg/kg twice a day until discharge. The enoxaparin therapy continued at home with 1 mg/kg twice a day for 18 patients (group I) and 1.5 mg/kg once a day for the other 17 patients (group II). Enoxaparin was discontinued 12-24 hours before delivery and restarted within 8-12 hours after delivery. Warfarin was given as adjuvant therapy along with enoxaparin in the post-partum period. Enoxaparin was discontinued when an international normalised ratio of 2 or above was reached. Differences between the two groups in terms of therapy response, complications and efficacy were recorded.

RESULTS

Thrombophilic disease was observed in three patients in each group. The iliac vein had the highest incidence of DVT in both groups. During therapy, two patients in group I were diagnosed with a mild haemorrhage; one patient (in group II) had abortion. There were no significant differences between groups in terms of recanalisation (measured by venous ultrasonography examination), post-thrombotic symptoms or safety parameters.

CONCLUSION

Enoxaparin can be used safely in DVT therapy during pregnancy. Our results indicate that therapy consisting of a single daily dose of 1.5 mg/kg enoxaparin is as effective as twice-daily administration.

Audit of the peri-delivery use of unfractionated heparin in women on therapeutic low-molecular weight heparin

There is no evidence-based approach for the optimal management of peri-delivery anticoagulation in women receiving therapeutic dose of low-molecular weight heparin (LMWH) during pregnancy. Nevertheless, the maintenance of anticoagulation for the maximal period peri-delivery appears appropriate in women considered to be at high risk of venous or arterial thromboembolism. We developed a regimen based on fixed thromboprophylactic dose of unfractionated heparin (UFH) peri-delivery and undertook an audit to evaluate the use and feasibility of this approach and any adverse events. Fixed intravenous thromboprophylactic dose of UFH (15,000 units/24 h) was commenced on the evening prior to a planned delivery [induction of labour or elective caesarean section (CS)], stopped 4 h predelivery and restarted 2-6 h postdelivery. Compliance was good with 32/38 consecutive deliveries managed according to the regimen. There were no cases of postpartum haemorrhage and no thrombosis associated with these 32 deliveries. Twenty-one patients were delivered by CS (11 elective) and eight patients received epidural/spinal anaesthesia without complication. In conclusion, the fixed thromboprophylactic dose UFH regimen provided maintenance of anticoagulation except for a matter of hours without excessive bleeding risk (conducive to neuroaxial anaesthesia) and was simple, flexible and acceptable to staff and patients.

Investigation of Direct Toxic and Teratogenic Effects of Anticoagulants on Rat Embryonic Development Using In Vitro Culture Method and Genotoxicity Assay

Heparin and low molecular weight heparins (LMWHs) are used to reduce the incidence of venous thromboembolism in pregnancy. Although, these agents have been shown to be safe when used during pregnancy, the studies about direct toxic and teratogenic effects of these drugs on embryonic development are limited. In this study, the effects of heparin and LMWHs on rat embryonic development were investigated by using in vitro embryo culture and micronucleus (MN) assay methods. Rat embryos were cultured in vitro in the presence of different concentrations of heparin (5-40 IU/ml), dalteparin (2.5-20 IU/ml), enoxaparin (25-100 microg/ml) and nadroparin (1-4 IU/ml). Effects of anticoagulants on embryonic developmental parameters were compared and embryos were evaluated for the presence of any malformations. After culturing the embryos, classic MN assay was performed. Anticoagulants significantly decreased all growth and developmental parameters dose-dependently. Dalteparin and enoxaparin were found to cause more developmental toxicity than heparin and nadroparin. Along with haematoma in general, heparin and nadroparin caused maxillary deformity, situs inversus and oedema most frequently, while neural tube defects were observed with dalteparin and enoxaparin. All agents also significantly induced MN formation in rat embryonic blood cells. These results indicate the possible genotoxic effects of anticoagulant agents on the developing rat embryo when applied directly.

Low-molecular-weight heparins for thromboprophylaxis and treatment of venous thromboembolism in pregnancy: a systematic review of safety and efficacy

To assess the safety and efficacy of low-molecular-weight heparins (LMWHs) for thromboprophylaxis and treatment of venous thromboembolism (VTE) in pregnancy, a systematic review of studies to the end of 2003 was undertaken. Data on VTE recurrence and side effects were extracted and cumulative incidences of VTE and adverse effects calculated. Of 81 reports identified, 64 reporting 2777 pregnancies were included. In 15 studies (174 patients) the indication for LMWH was treatment of acute VTE, and in 61 studies (2603 pregnancies) it was thromboprophylaxis or adverse pregnancy outcome. There were no maternal deaths. VTE and arterial thrombosis (associated with anti-phospholipid syndrome) were reported in 0.86% (95% confidence interval [CI], 0.55%-1.28%) and 0.50% (95% CI, 0.28%-0.84%) of pregnancies, respectively. Significant bleeding, generally associated with primary obstetric causes, occurred in 1.98% (95% CI, 1.50%-2.57%), allergic skin reactions in 1.80% (95% CI, 1.34%-2.37%), heparin-induced thrombocytopenia in 0%, thrombocytopenia (unrelated to LMWH) in 0.11% (95% CI, 0.02%-0.32%), and osteoporotic fracture in 0.04% (95% CI, < 0.01%-0.20%) of pregnancies. Overall, live births were reported in 94.7% of pregnancies, including 85.4% in those receiving LMWH for recurrent pregnancy loss. LMWH is both safe and effective to prevent or treat VTE in pregnancy.

Low-molecular-weight heparin for the prevention and treatment of venous thromboembolism in pregnancy

PURPOSE OF REVIEW

Low-molecular-weight heparins (LMWHs) have largely replaced unfractionated heparins for both prophylaxis and treatment of venous thromboembolism in nonpregnant patients. However, until recently, evidence in pregnant women was lacking, despite the increasing use of LMWHs during pregnancy in clinical practice. This review covers recent literature on the use of LMWHs in relation to pregnancy.

RECENT FINDINGS

The main areas covered in this review are the use of LMWHs in both prophylaxis and treatment of venous thromboembolism in pregnancy. The review also considers issues relating to monitoring of LMWHs in pregnancy, and safety from both a maternal and a fetal perspective.

SUMMARY

The available evidence demonstrates that LMWHs are of at least equivalent efficacy but have a better safety profile compared with unfractionated heparins in both prophylaxis and treatment of maternal venous thromboembolism, and are more convenient to administer. There is no consensus with respect to whether these agents require monitoring during pregnancy other than periodic checking of the platelet count. The clinical implication from the available evidence is that LMWHs should now be regarded as the anticoagulant agents of choice for both prophylaxis and treatment of maternal venous thromboembolism.

Safety of low molecular weight heparins in the treatment of venous thromboembolism

Low molecular weight heparins (LMWHs) are commonly employed as a substitute for unfractionated heparin (UFH) in the treatment of venous thromboembolic events. Despite their higher cost, the preferential use of LMWHs seemed justified initially as, based on the results of earlier meta-analyses, these compounds were deemed to be more effective and safer than UFH. Although, in this respect, their purported superiority over UFH could not be confirmed by subsequent large, randomised trials and updated meta-analyses, other peculiar features of LMWHs were highlighted, favouring their preferential utilisation in patients with venous thromboembolism. Among these, the possibility of once-daily administration on an out-patient basis, the lower incidence of Type II heparin-induced thrombocytopenia and the lower likelihood of osteoporosis after prolonged treatment periods, appear to be especially prominent. This review attempts to evaluate the available evidence focusing on the safety of LMWHs for the treatment of venous thromboembolism and the current therapeutic options and potential advantages of LMWHs, either in general or in selected patient populations.