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Clinical Laboratory Apr 2023Thrombophilia testing is controversial, not least because of its high cost. Because comprehensive valid testing requires standardized blood collection close by the... (Review)
Review
BACKGROUND
Thrombophilia testing is controversial, not least because of its high cost. Because comprehensive valid testing requires standardized blood collection close by the specialized laboratory, and interpretation of findings together with clinical data, often only part of the necessary laboratory analyses can be performed in remote central laboratories. Restrictive indications for testing, as have been recommended by previous reviews on the topic, have been based on incomplete analytics, studies with small case numbers, or short observation periods, and on an inappropriate, simple risk stratification for venous thromboembolism (VTE), further subdivided into provoked and unprovoked events.
METHODS
The authors reviewed four electronic databases for all peer-reviewed and in-press articles about thrombophilia, VTE, obstetric complications, and arterial thrombosis. After confirmation for relevance to the topic, 201 articles were accepted for inclusion in this article. This review summarizes the studies relevant to the evaluation of thrombophilic conditions, and their combination with each other and with clinical risk factors, to stratify individual risk for thromboembolism and obstetric complications.
RESULTS
Thrombophilia testing requires highly skilled personnel for laboratory analysis and interpretation. Clinical conditions that influence the results as well as special preanalytical, analytical, and postanalytical aspects must be considered if valid results are to be obtained. Tests involved include the natural anticoagulants antithrombin, protein C, and protein S; the procoagulants fibrinogen (dysfibrinogen), prothrombin (mutation G20210A), factor V (Leiden mutation), factor VIII/von Willebrand factor/blood group ABO, factor IX, and factor XI; the anti-phospholipid antibodies to detect an antiphospholipid syndrome and potentially additional uncertain thrombophilic conditions. The risks of thrombophilic conditions and clinical risk factors for VTE are cumulative or even supra-additive. Scores from thrombophilic conditions and other genetic and nongenetic risk factors permit estimation of risk for first and recurrent VTE. Therapeutic strategies can be derived from this risk stratification.
CONCLUSIONS
Thrombophilia testing is indicated when the results have potential to influence the type and duration of treatment. Indications include certain patients after VTE; or patients without previous VTE but with positive family history regarding VTE or thrombophilia before major surgery, pregnancy, combined oral contraceptives, or hormone replacement therapy. Whether or not thrombophilia is present should help determine anticoagulation, hormonal contraception, or hormone replacement.
Topics: Female; Pregnancy; Humans; Venous Thromboembolism; Thrombophilia; Anticoagulants; Risk Factors
PubMed: 37057948
DOI: 10.7754/Clin.Lab.2022.220817 -
JAMA Network Open Nov 2022Direct oral anticoagulant (DOAC)-associated intracranial hemorrhage (ICH) has high morbidity and mortality. The safety and outcome data of DOAC reversal agents in ICH... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Direct oral anticoagulant (DOAC)-associated intracranial hemorrhage (ICH) has high morbidity and mortality. The safety and outcome data of DOAC reversal agents in ICH are limited.
OBJECTIVE
To evaluate the safety and outcomes of DOAC reversal agents among patients with ICH.
DATA SOURCES
PubMed, MEDLINE, The Cochrane Library, Embase, EBSCO, Web of Science, and CINAHL databases were searched from inception through April 29, 2022.
STUDY SELECTION
The eligibility criteria were (1) adult patients (age ≥18 years) with ICH receiving treatment with a DOAC, (2) reversal of DOAC, and (3) reported safety and anticoagulation reversal outcomes. All nonhuman studies and case reports, studies evaluating patients with ischemic stroke requiring anticoagulation reversal or different dosing regimens of DOAC reversal agents, and mixed study groups with DOAC and warfarin were excluded.
DATA EXTRACTION AND SYNTHESIS
Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were used for abstracting data and assessing data quality and validity. Two reviewers independently selected the studies and abstracted data. Data were pooled using the random-effects model.
MAIN OUTCOMES AND MEASURES
The primary outcome was proportion with anticoagulation reversed. The primary safety end points were all-cause mortality and thromboembolic events after the reversal agent.
RESULTS
A total of 36 studies met criteria for inclusion, with a total of 1832 patients (967 receiving 4-factor prothrombin complex concentrate [4F-PCC]; 525, andexanet alfa [AA]; 340, idarucizumab). The mean age was 76 (range, 68-83) years, and 57% were men. For 4F-PCC, anticoagulation reversal was 77% (95% CI, 72%-82%; I2 = 55%); all-cause mortality, 26% (95% CI, 20%-32%; I2 = 68%), and thromboembolic events, 8% (95% CI, 5%-12%; I2 = 41%). For AA, anticoagulation reversal was 75% (95% CI, 67%-81%; I2 = 48%); all-cause mortality, 24% (95% CI, 16%-34%; I2 = 73%), and thromboembolic events, 14% (95% CI, 10%-19%; I2 = 16%). Idarucizumab for reversal of dabigatran had an anticoagulation reversal rate of 82% (95% CI, 55%-95%; I2 = 41%), all-cause mortality, 11% (95% CI, 8%-15%, I2 = 0%), and thromboembolic events, 5% (95% CI, 3%-8%; I2 = 0%). A direct retrospective comparison of 4F-PCC and AA showed no differences in anticoagulation reversal, proportional mortality, or thromboembolic events.
CONCLUSIONS AND RELEVANCE
In the absence of randomized clinical comparison trials, the overall anticoagulation reversal, mortality, and thromboembolic event rates in this systematic review and meta-analysis appeared similar among available DOAC reversal agents for managing ICH. Cost, institutional formulary status, and availability may restrict reversal agent choice, particularly in small community hospitals.
Topics: Male; Adult; Humans; Aged; Adolescent; Female; Hemorrhage; Retrospective Studies; Anticoagulant Reversal Agents; Anticoagulation Reversal; Anticoagulants; Intracranial Hemorrhages; Thromboembolism
PubMed: 36331504
DOI: 10.1001/jamanetworkopen.2022.40145 -
Journal of the American Heart... Oct 2019Background Inherited thrombophilias are well-established predisposing factors for venous thromboembolism, but their role in arterial thrombosis, such as arterial... (Meta-Analysis)
Meta-Analysis
Background Inherited thrombophilias are well-established predisposing factors for venous thromboembolism, but their role in arterial thrombosis, such as arterial ischemic stroke, remains uncertain. We aimed to evaluate the association between inherited thrombophilia (factor V Leiden, prothrombin G20210A mutation, protein C deficiency, protein S deficiency, and antithrombin deficiency) and risk of arterial ischemic stroke in adults. Methods and Results We searched PubMed, EMBASE, and Cochrane Library Databases from inception to December 31, 2018. We included case-control or cohort studies of adults reporting the prevalence of inherited thrombophilias in those with arterial ischemic stroke and subjects without arterial ischemic stroke. Two reviewers (T.C., E.D.) independently searched the literature and extracted data. Pooled odds ratios (ORs) and 95% CIs were calculated using random-effects model. We identified 68 eligible studies, which collectively enrolled 11 916 stroke patients and 96 057 controls. The number of studies reporting factor V Leiden, prothrombin G20210A mutation, protein C deficiency, protein S deficiency, and antithrombin deficiency were 56, 45, 15, 17, and 12, respectively. Compared with controls, patients with arterial ischemic stroke were significantly more likely to have the following inherited thrombophilias: factor V Leiden (OR, 1.25; 95% CI, 1.08-1.44; I=0%), prothrombin G20210A mutation (OR, 1.48; 95% CI, 1.22-1.80; I=0%), protein C deficiency (OR, 2.13; 95% CI, 1.16-3.90; I=0%), and protein S deficiency (OR, 2.26; 95% CI, 1.34-3.80; I=8.8%). Statistical significance was not reached for antithrombin deficiency (OR, 1.25; 95% CI, 0.58-2.67; I=8.8%). Conclusions Inherited thrombophilias (factor V Leiden, prothrombin G20210A mutation, protein C deficiency, and protein S deficiency) are associated with an increased risk of arterial ischemic stroke in adults. The implications of these findings with respect to clinical management of patients with ischemic stroke require further investigation.
Topics: Adult; Aged; Blood Coagulation; Blood Coagulation Disorders, Inherited; Brain Ischemia; Female; Genetic Predisposition to Disease; Humans; Male; Middle Aged; Phenotype; Prognosis; Risk Assessment; Risk Factors; Stroke; Thrombophilia
PubMed: 31549567
DOI: 10.1161/JAHA.119.012877 -
Critical Care Medicine Oct 2021To combine evidence on andexanet alfa and prothrombin complex concentrates for factor Xa inhibitor-associated bleeding to guide clinicians on reversal strategies. (Meta-Analysis)
Meta-Analysis
OBJECTIVES
To combine evidence on andexanet alfa and prothrombin complex concentrates for factor Xa inhibitor-associated bleeding to guide clinicians on reversal strategies.
DATA SOURCES
Embase, Pubmed, Web of Science, and the Cochrane Library.
STUDY SELECTION
Observational studies and randomized clinical trials studying hemostatic effectiveness of andexanet alfa or prothrombin complex concentrate for acute reversal of factor Xa inhibitor-associated hemorrhage.
DATA EXTRACTION
Two independent reviewers extracted the data from the studies. Visualization and comparison of hemostatic effectiveness using Sarode et al or International Society of Thrombosis and Hemostasis Scientific and Standardization Committee criteria at 12 and 24 hours, (venous) thrombotic event rates, and inhospital mortality were performed by constructing Forest plots. Exploratory analysis using a logistic mixed model analysis was performed to identify factors associated with effectiveness and venous thromboembolic event.
DATA SYNTHESIS
A total of 21 studies were included (andexanet: 438 patients; prothrombin complex concentrate: 1,278 patients). The (weighted) mean effectiveness for andexanet alfa was 82% at 12 hours and 71% at 24 hours. The (weighted) mean effectiveness for prothrombin complex concentrate was 88% at 12 hours and 76% at 24 hours. The mean 30-day symptomatic venous thromboembolic event rates were 5.0% for andexanet alfa and 1.9% for prothrombin complex concentrate. The mean 30-day total thrombotic event rates for andexanet alfa and prothrombin complex concentrate were 10.7% and 3.1%, respectively. Mean inhospital mortality was 23.3% for andexanet versus 15.8% for prothrombin complex concentrate. Exploratory analysis controlling for potential confounders did not demonstrate significant differences between both reversal agents.
CONCLUSIONS
Currently, available evidence does not unequivocally support the clinical effectiveness of andexanet alfa or prothrombin complex concentrate to reverse factor Xa inhibitor-associated acute major bleeding, nor does it permit conventional meta-analysis of potential superiority. Neither reversal agent was significantly associated with increased effectiveness or a higher rate of venous thromboembolic event. These results underscore the importance of randomized controlled trials comparing the two reversal agents and may provide guidance in designing institutional guidelines.
Topics: Coagulants; Factor Xa; Factor Xa Inhibitors; Hemorrhage; Humans; Prothrombin; Recombinant Proteins
PubMed: 33967205
DOI: 10.1097/CCM.0000000000005059 -
BMJ (Clinical Research Ed.) Jul 2022To assess the benefits and harms of different types and doses of anticoagulant drugs for the prevention of venous thromboembolism in patients who are acutely ill and... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To assess the benefits and harms of different types and doses of anticoagulant drugs for the prevention of venous thromboembolism in patients who are acutely ill and admitted to hospital.
DESIGN
Systematic review and network meta-analysis.
DATA SOURCES
Cochrane CENTRAL, PubMed/Medline, Embase, Web of Science, clinical trial registries, and national health authority databases. The search was last updated on 16 November 2021.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Published and unpublished randomised controlled trials that evaluated low or intermediate dose low-molecular-weight heparin, low or intermediate dose unfractionated heparin, direct oral anticoagulants, pentasaccharides, placebo, or no intervention for the prevention of venous thromboembolism in acutely ill adult patients in hospital.
MAIN OUTCOME MEASURES
Random effects, bayesian network meta-analyses used four co-primary outcomes: all cause mortality, symptomatic venous thromboembolism, major bleeding, and serious adverse events at or closest timing to 90 days. Risk of bias was also assessed using the Cochrane risk-of-bias 2.0 tool. The quality of evidence was graded using the Confidence in Network Meta-Analysis framework.
RESULTS
44 randomised controlled trials that randomly assigned 90 095 participants were included in the main analysis. Evidence of low to moderate quality suggested none of the interventions reduced all cause mortality compared with placebo. Pentasaccharides (odds ratio 0.32, 95% credible interval 0.08 to 1.07), intermediate dose low-molecular-weight heparin (0.66, 0.46 to 0.93), direct oral anticoagulants (0.68, 0.33 to 1.34), and intermediate dose unfractionated heparin (0.71, 0.43 to 1.19) were most likely to reduce symptomatic venous thromboembolism (very low to low quality evidence). Intermediate dose unfractionated heparin (2.63, 1.00 to 6.21) and direct oral anticoagulants (2.31, 0.82 to 6.47) were most likely to increase major bleeding (low to moderate quality evidence). No conclusive differences were noted between interventions regarding serious adverse events (very low to low quality evidence). When compared with no intervention instead of placebo, all active interventions did more favourably with regard to risk of venous thromboembolism and mortality, and less favourably with regard to risk of major bleeding. The results were robust in prespecified sensitivity and subgroup analyses.
CONCLUSIONS
Low-molecular-weight heparin in an intermediate dose appears to confer the best balance of benefits and harms for prevention of venous thromboembolism. Unfractionated heparin, in particular the intermediate dose, and direct oral anticoagulants had the least favourable profile. A systematic discrepancy was noted in intervention effects that depended on whether placebo or no intervention was the reference treatment. Main limitations of this study include the quality of the evidence, which was generally low to moderate due to imprecision and within-study bias, and statistical inconsistency, which was addressed post hoc.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42020173088.
Topics: Anticoagulants; Bayes Theorem; Hemorrhage; Heparin; Heparin, Low-Molecular-Weight; Hospitals; Humans; Network Meta-Analysis; Randomized Controlled Trials as Topic; Thrombosis; Venous Thromboembolism
PubMed: 35788047
DOI: 10.1136/bmj-2022-070022 -
Journal of the American College of... Jun 2021Direct oral anticoagulants (DOACs) have shown a positive benefit-risk balance in both clinical trials and real-world data, but approximately 2% to 3.5% of patients... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Direct oral anticoagulants (DOACs) have shown a positive benefit-risk balance in both clinical trials and real-world data, but approximately 2% to 3.5% of patients experience major bleeding annually. Many of these patients require hospitalization, and the administration of reversal agents may be required to control bleeding.
OBJECTIVES
The aim of this study was to investigate clinical outcomes associated with the use of 4-factor prothrombin complex concentrates, idarucizumab, or andexanet for reversal of severe DOAC-associated bleeding.
METHODS
The investigators systematically searched for studies of reversal agents for the treatment of severe bleeding associated with DOAC. Mortality rates, thromboembolic events, and hemostatic efficacy were meta-analyzed using a random effects model.
RESULTS
The investigators evaluated 60 studies in 4,735 patients with severe DOAC-related bleeding who were treated with 4-factor prothrombin complex concentrates (n = 2,688), idarucizumab (n = 1,111), or andexanet (n = 936). The mortality rate was 17.7% (95% confidence interval [CI]: 15.1% to 20.4%), and it was higher in patients with intracranial bleedings (20.2%) than in patients with extracranial hemorrhages (15.4%). The thromboembolism rate was 4.6% (95% CI: 3.3% to 6.0%), being particularly high with andexanet (10.7%; 95% CI: 6.5% to 15.7%). The effective hemostasis rate was 78.5% (95% CI: 75.1% to 81.8%) and was similar regardless of the reversal agent considered. The rebleeding rate was 13.2% (95% CI: 5.5% to 23.1%) and 78% of rebleeds occurred after resumption of anticoagulation. The risk of death was markedly and significantly associated with failure to achieve effective hemostasis (relative risk: 3.63; 95% CI: 2.56 to 5.16). The results were robust regardless of the type of study or the hemostatic scale used.
CONCLUSIONS
The risk of death after severe DOAC-related bleeding remains significant despite a high rate of effective hemostasis with reversal agents. Failure to achieve effective hemostasis strongly correlated with a fatal outcome. Thromboembolism rates are particularly high with andexanet. Comparative clinical trials are needed.
Topics: Administration, Oral; Antibodies, Monoclonal, Humanized; Anticoagulants; Blood Coagulation; Blood Coagulation Factors; Factor Xa; Hemorrhage; Hemostasis; Humans; Recombinant Proteins; Retrospective Studies
PubMed: 34140101
DOI: 10.1016/j.jacc.2021.04.061 -
Critical Care (London, England) Nov 2023Trauma-induced coagulopathy (TIC) is common in trauma patients with major hemorrhage. Prothrombin complex concentrate (PCC) is used as a potential treatment for the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Trauma-induced coagulopathy (TIC) is common in trauma patients with major hemorrhage. Prothrombin complex concentrate (PCC) is used as a potential treatment for the correction of TIC, but the efficacy, timing, and evidence to support its use in injured patients with hemorrhage are unclear.
METHODS
A systematic search of published studies was performed on MEDLINE and EMBASE databases using standardized search equations. Ongoing studies were identified using clinicaltrials.gov. Studies investigating the use of PCC to treat TIC (on its own or in combination with other treatments) in adult major trauma patients were included. Studies involving pediatric patients, studies of only traumatic brain injury (TBI), and studies involving only anticoagulated patients were excluded. Primary outcomes were in-hospital mortality and venous thromboembolism (VTE). Pooled effects of PCC use were reported using random-effects model meta-analyses. Risk of bias was assessed for each study, and we used the Grading of Recommendations Assessment, Development, and Evaluation to assess the quality of evidence.
RESULTS
After removing duplicates, 1745 reports were screened and nine observational studies and one randomized controlled trial (RCT) were included, with a total of 1150 patients receiving PCC. Most studies used 4-factor-PCC with a dose of 20-30U/Kg. Among observational studies, co-interventions included whole blood (n = 1), fibrinogen concentrate (n = 2), or fresh frozen plasma (n = 4). Outcomes were inconsistently reported across studies with wide variation in both measurements and time points. The eight observational studies included reported mortality with a pooled odds ratio of 0.97 [95% CI 0.56-1.69], and five reported deep venous thrombosis (DVT) with a pooled OR of 0.83 [95% CI 0.44-1.57]. When pooling the observational studies and the RCT, the OR for mortality and DVT was 0.94 [95% CI 0.60-1.45] and 1.00 [95% CI 0.64-1.55] respectively.
CONCLUSIONS
Among published studies of TIC, PCCs did not significantly reduce mortality, nor did they increase the risk of VTE. However, the potential thrombotic risk remains a concern that should be addressed in future studies. Several RCTs are currently ongoing to further explore the efficacy and safety of PCC.
Topics: Adult; Humans; Child; Venous Thromboembolism; Blood Coagulation Factors; Blood Coagulation Disorders; Hemorrhage; Randomized Controlled Trials as Topic
PubMed: 37919775
DOI: 10.1186/s13054-023-04688-z -
Annals of the Academy of Medicine,... Apr 2021Coronavirus disease 2019 (COVID-19)-induced coagulopathy (CIC) has been widely reported in the literature. However, the spectrum of abnormalities associated with CIC has... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Coronavirus disease 2019 (COVID-19)-induced coagulopathy (CIC) has been widely reported in the literature. However, the spectrum of abnormalities associated with CIC has been highly variable.
METHODS
We conducted a systematic review of the literature (until 1 June 2020) to assess CIC and disease severity during the early COVID-19 pandemic. Primary outcomes were pooled mean differences in platelet count, D-dimer level, prothrombin time, activated partial thromboplastin time (aPTT) and fibrinogen level between non-severe and severe patients, stratified by degree of hypoxaemia or those who died. The risk factors for CIC were analysed. Random-effects meta-analyses and meta-regression were performed using R version 3.6.1, and certainty of evidence was rated using the Grading of Recommendation, Assessment, Development, and Evaluation approach.
RESULTS
Of the included 5,243 adult COVID-19 patients, patients with severe COVID-19 had a significantly lower platelet count, and higher D-dimer level, prothrombin time and fibrinogen level than non-severe patients. Pooled mean differences in platelet count (-19.7×109/L, 95% confidence interval [CI] -31.7 to -7.6), D-dimer level (0.8μg/mL, 95% CI 0.5-1.1), prothrombin time (0.4 second, 95% CI 0.2-0.6) and fibrinogen level (0.6g/L, 95% CI 0.3-0.8) were significant between the groups. Platelet count and D-dimer level were significant predictors of disease severity on meta-regression analysis. Older men had higher risks of severe coagulopathic disease.
CONCLUSION
Significant variability in CIC exists between non-severe and severe patients, with platelet count and D-dimer level correlating with disease severity. Routine monitoring of all coagulation parameters may help to assess CIC and decide on the appropriate management.
Topics: Adult; Aged; Blood Coagulation Disorders; COVID-19; Humans; Male; Pandemics; Prothrombin Time; SARS-CoV-2
PubMed: 33990820
DOI: 10.47102/annals-acadmedsg.2020420 -
EClinicalMedicine May 2023Isolated pulmonary embolism (PE) appears to be associated with a specific clinical profile and sequelae compared to deep vein thrombosis (DVT)-associated PE. The...
BACKGROUND
Isolated pulmonary embolism (PE) appears to be associated with a specific clinical profile and sequelae compared to deep vein thrombosis (DVT)-associated PE. The objective of this study was to identify clinical characteristics that discriminate both phenotypes, and to characterize their differences in clinical outcome.
METHODS
We performed a systematic review and meta-analysis of studies comparing PE phenotypes. A systematic search of the electronic databases PubMed and CENTRAL was conducted, from inception until January 27, 2023. Exclusion criteria were irrelevant content, inability to retrieve the article, language other than English or German, the article comprising a review or case study/series, and inappropriate study design. Data on risk factors, clinical characteristics and clinical endpoints were pooled using random-effects meta-analyses.
FINDINGS
Fifty studies with 435,768 PE patients were included. In low risk of bias studies, 30% [95% CI 19-42%, = 97%] of PE were isolated. The Factor V Leiden [OR: 0.47, 95% CI 0.37-0.58, = 0%] and prothrombin G20210A mutations [OR: 0.55, 95% CI 0.41-0.75, = 0%] were significantly less prevalent among patients with isolated PE. Female sex [OR: 1.30, 95% CI 1.17-1.45, = 79%], recent invasive surgery [OR: 1.31, 95% CI 1.23-1.41, = 65%], a history of myocardial infarction [OR: 2.07, 95% CI 1.85-2.32, = 0%], left-sided heart failure [OR: 1.70, 95% CI 1.37-2.10, = 76%], peripheral artery disease [OR: 1.36, 95% CI 1.31-1.42, = 0%] and diabetes mellitus [OR: 1.23, 95% CI 1.21-1.25, = 0%] were significantly more frequently represented among isolated PE patients. In a synthesis of clinical outcome data, the risk of recurrent VTE in isolated PE was half that of DVT-associated PE [RR: 0.55, 95% CI 0.44-0.69, = 0%], while the risk of arterial thrombosis was nearly 3-fold higher [RR: 2.93, 95% CI 1.43-6.02, = 0%].
INTERPRETATION
Our findings suggest that isolated PE appears to be a specific entity that may signal a long-term risk of arterial thrombosis. Randomised controlled trials are necessary to establish whether alternative treatment regimens are beneficial for this patient subgroup.
FUNDING
None.
PubMed: 37152363
DOI: 10.1016/j.eclinm.2023.101973 -
Human Reproduction (Oxford, England) Apr 2021Is there an association between hereditary thrombophilia in pregnant women and risk of recurrent pregnancy loss (RPL)? (Meta-Analysis)
Meta-Analysis
STUDY QUESTION
Is there an association between hereditary thrombophilia in pregnant women and risk of recurrent pregnancy loss (RPL)?
SUMMARY ANSWER
Pregnant women with hereditary thrombophilia have an increased risk of RPL, especially for pregnant women with the G1691A mutation of the factor V Leiden (FVL) gene, the G20210A mutation of the prothrombin gene (PGM), and deficiency of protein S (PS).
WHAT IS KNOWN ALREADY
Prior studies have suggested that pregnant women with hereditary thrombophilia have a higher risk of RPL, however, the results are inconsistent; furthermore, a complete overview is missing. This lack of information is an obstacle to the risk assessment of RPL in pregnant women with hereditary thrombophilia. A comprehensive meta-analysis on the relation between hereditary thrombophilia and the risk of RPL is needed.
STUDY DESIGN, SIZE, DURATION
A systematic review and meta-analysis was performed using observational studies published in English before 1 April 2020 to evaluate the relation between hereditary thrombophilia and risk of RPL.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Relevant studies were identified from PubMed, Web of Science, and EMBASE searches and complemented with perusal of bibliographies of retrieved articles. The exposure of interest was hereditary thrombophilia, including FVL mutation, PGM, deficiency of antithrombin (AT), deficiency of protein C (PC), and deficiency of PS. The overall risk estimates were pooled using random effects models. Subgroup and sensitivity analyses were carried out to explore possible sources of heterogeneity and assess the robustness of the results.
MAIN RESULTS AND THE ROLE OF CHANCE
A total of 89 studies involving 30 254 individuals were included. Results showed that women with FVL mutation (odds ratio (OR): 2.44, 95% CI: 1.96-3.03), PGM (OR: 2.08, 95% CI: 1.61-2.68), or deficiency of PS (OR: 3.45, 95% CI: 1.15-10.35) had higher risks of developing RPL. Compared with the reference group, there was no observed relation between a deficiency in AT or PC and RPL (all P > 0.05). Heterogeneity in the risk estimates of RPL was partially explained by geographic region, definitions of RPL, types of RPL, and controlled confounders. Sensitivity analyses validated the robustness of the findings.
LIMITATIONS, REASONS FOR CAUTION
Only 39 of the included studies controlled for one or more confounders, and the heterogeneity across all included studies was high. Based on the data available, we cannot determine whether this association is confounded by other potential risk factors of RPL.
WIDER IMPLICATIONS OF THE FINDINGS
This systematic review and meta-analysis show a possible association between hereditary thrombophilia and an increased risk of RPL, suggesting that testing for hereditary thrombophilia should be considered in individuals with RPL.
STUDY FUNDING/COMPETING INTEREST(S)
The study was funded by the Hunan Provincial Key Research and Development Program (Grant number: 2018SK2062) and National Natural Science Foundation Program (Grant number: 81973137). There are no conflicts of interest.
REGISTRATION NUMBER
N/A.
Topics: Abortion, Habitual; Female; Humans; Mutation; Odds Ratio; Pregnancy; Risk Factors; Thrombophilia
PubMed: 33575779
DOI: 10.1093/humrep/deab010