Prevention and Treatment of VTE and Pregnancy

Describe your topic.: VTE in Pregnancy

Describe why this topic is important.: Anticoagulant therapy is indicated during pregnancy for the prevention and treatment of VTE; for the prevention and treatment of systemic embolism in patients with mechanical heart valves; and, in combination with aspirin, for the prevention of recurrent pregnancy loss in women with antiphospholipid antibodies (APLAs). The use of anticoagulation for prevention of pregnancy complications in women with hereditary thrombophilia is becoming more frequent. Given the absence of proven-effective therapy in women with unexplained recurrent pregnancy loss, there is also growing pressure to intervene with antithrombotic therapy in affected women with no known underlying thrombophilia. The use of anticoagulant therapy during pregnancy is challenging because of the potential for fetal and maternal complications.

Tell us why you are suggesting this topic.: VTE, Thrombophilia, Antithrombotic Therapy, and Pregnancy has been the focus of 9 editions of evidence-based guidelines developed by the American College of Chest Physicians (CHEST), the last of which was published in 2012 and accepted by the National Guideline Clearinghouse. CHEST aims to update its guidelines every 5 years per the National Academy of Medicine (formerly IOM) and AHRQ standards, but due to increased demand for guidelines, has fallen short on this objective. Development of an evidence review on at least some, if not all, of the PICO’s described above would serve as the source document to facilitate the update of these guidelines.

Target Date.

Describe what you are doing currently and what you are hoping will change because of a new evidence report.

As described above, evidence reports form the basis of all CHEST clinical practice guidelines. If this topic is selected for an AHRQ evidence report, the results of that report will directly inform an update of the guideline on VTE, Thrombophilia, Antithrombotic Therapy, and Pregnancy. The original selection of this topic was due to professional demand based on inconsistent or lack of clear guidance based on current evidence. CHEST guidelines have been touted as a useful tool to assist in clinical decision-making, resulting in improved concordance between practice and the larger body of published evidence. In order to meet the National Academy of Medicine (formerly IOM) standards, it is imperative that an updated evidence report be developed to update the guidelines.

How will you or your group use the information from a new evidence report?

As described above, the evidence report will be directly used to inform the update of evidence-based guidelines on this topic.

How would you or your group plan to disseminate information from the report? Who would you plan to disseminate it to?

The report will be disseminated in the following ways: 1) communications to CHEST membership (nearly 19,000 healthcare providers) via electronic (ie eNews Alerts), print (ie CHEST Physician Newsletter), and social media. There will also be opportunities to inform providers about the report through our eLearning and Live Learning platforms, including our Annual Conference. Finally, the report will be referenced as the source document for the subsequent update of the guideline, furthering dissemination of the report as well as use of its contents in clinical practice.

Do you know of organizations that could use an evidence report to change clinical practice? Are you a part of, or have you been in contact with, any organizations that might implement the research findings of an evidence report?

CHEST serves as the primary organization that will directly use this evidence report to update our clinical practice guideline on VTE, Thrombophilia, Antithrombotic Therapy, and Pregnancy. Such guidelines have the opportunity to change clinical practice by improving clinical decisions in concordance with current evidence. Other organizations that would also benefit from this evidence report include: the American Thoracic Society, the American Society of Hematology, and the American College of Obstetricians and Gynocologists.

Information About You: (optional)

Provide a description of your role or perspective.: The American College of Chest Physicians (CHEST) is a professional society

If you are you making a suggestion on behalf of an organization, please state the name of the organization.: The American College of CHEST Physicians

Please tell us how you heard about the Effective Health Care Program.: CHEST has collaborated with AHRQ in the past on evidence reviews, most recently the VTE Prophylaxis in Orthopedic Surgery Update

We are suggesting the following PICO questions pertaining to the management of Venous thromboembolism (VTE) and thrombophilia during pregnancy as well as the use of antithrombotic agents in pregnant women.

Population	Intervention	Comparison	Outcome
Safety and Adverse Outcome PICO Questions
Pregnant women	Unfractionated heparin Low-molecular-weight heparin Other relevant agents	No antithrombotic therapy or Other antithrombotic therapy	Fetal hemorrhage Pregnancy loss Congenital malformations Developmental delay Levels or results of coagulation testing in umbilical cord blood Birth weight (centile); number small for dates
Fetuses and children of women using antithrombotic therapy during pregnancy	Vitamin K antagonists Unfractionated heparin Low-molecular-weight heparin Other relevant agents	No antithrombotic therapy exposure or Other antithrombotic agent	Fetal hemorrhage Pregnancy loss Congenital malformations Developmental delay Levels or results of coagulation testing in umbilical cord blood Birth weight (centile); number small for dates
Breast-fed infants of women receiving antithrombotic therapy	Vitamin K antagonists Unfractionated heparin Low-molecular-weight heparin Other relevant agents	No antithrombotic therapy exposure or Other antithrombotic agent	Infant hemorrhage Levels or results of coagulation testing in breast milk Levels or results of coagulation testing in plasma of breast-fed infants
Prevention & Risk PICO Questions
Women using assisted reproductive technology to become pregnant	No prophylaxis	No intervention	Proportion of pregnancies that are successful DVT Pulmonary embolism Mortality Major bleeding Bleeding during oocyte retrieval and embryo transfer
Women using assisted reproductive technology to become pregnant	Low-molecular-weight heparin Unfractionated heparin Graduated compression stockings Other relevant agents	No prophylaxis or Other intervention	DVT Pulmonary embolism Mortality Major bleeding Bleeding during oocyte retrieval and embryo transfer
Pregnant women undergoing cesarean section	No prophylaxis	No intervention	DVT Pulmonary embolism Embolism Mortality Major bleeding Epidural hematoma
Pregnant women undergoing cesarean section	Low molecular weight heparin Unfractionated heparin Graduated compression stockings Intermittent pneumatic compression Combined mechanical and pharmacologic prophylaxis Other relevant agents	No prophylaxis or Other antithrombotic strategy	DVT Pulmonary embolism Mortality Major bleeding: total Major bleeding Epidural hematoma
Pregnant women with prior VTE	No prophylaxis	No intervention	Symptomatic DVT, pulmonary embolism Mortality Major bleeding: total Postthrombotic syndrome
Pregnant women with prior VTE	No antepartum prophylaxis, postpartum only -All relevant agents considered Antepartum and postpartum prophylaxis -All relevant agents considered	No prophylaxis	Symptomatic recurrent DVT or pulmonary embolism Major bleeding: total Postthrombotic syndrome
Pregnant women with thrombophilia and no prior VTE	No prophylaxis	No intervention	Symptomatic DVT, pulmonary embolism Mortality Major bleeding
Pregnant women with thrombophilia and no prior VTE	No antepartum prophylaxis, postpartum only -Low-molecular-weight heparin -Unfractionated heparin -Other relevant agents -Graduated compression stockings -Combined mechanical and pharmacologic prophylaxis Antepartum and postpartum prophylaxis -Similar agents as above	No prophylaxis or Other intervention	Symptomatic DVT, pulmonary embolism Mortality Major bleeding
Pregnant women with thrombophilia and a history of pregnancy complications -Recurrent early pregnancy loss -Late pregnancy loss (single) -Late pregnancy loss (multiple) -Pre-eclampsia -Intrauterine growth restriction -Placental abruption	No prophylaxis	No intervention	Recurrent pregnancy complication (as defined under patient population) Symptomatic DVT, pulmonary embolism Mortality Major bleeding
Pregnant women with thrombophilia (antiphospholipid antibodies vs congenital thrombophilia vs specific congenital thrombophilia) and a history of pregnancy complications -Recurrent early pregnancy loss -Late pregnancy loss (single) -Late pregnancy loss (multiple) -Preeclampsia -Intrauterine growth restriction -Placental abruption	Aspirin Unfractionated heparin ( +/- aspirin) Low-molecular-weight heparin (+/-aspirin)	No prophylaxis or Other antithrombotic strategy	Recurrent pregnancy complication (as defined under patient population) Symptomatic DVT, pulmonary embolism Mortality Major bleeding
Pregnant women with no known thrombophilia and prior preeclampsia Pregnant women with no known thrombophilia and at least two prior pregnancy losses	Aspirin Unfractionated heparin (+/- aspirin) Low-molecular-weight heparin (+/- aspirin)	No prophylaxis	Recurrent preeclampsia Recurrent pregnancy loss
Pregnant women with mechanical heart valves	No antithrombotic therapy	No intervention	Maternal thromboembolism Major bleeding: total Major bleeding: maternal death Congenital malformations Fetal/neonatal hemorrhage Pregnancy loss
Pregnant women with mechanical heart valves	Vitamin K antagonists throughout pregnancy Unfractionated heparin throughout pregnancy Low-molecular-weight throughout pregnancy Vitamin K antagonists substituted with unfractionated heparin during first trimester (at or before 6 wk) Vitamin K antagonists substituted with low-molecular-weight heparin during first trimester (at or before 6 wk) Vitamin K antagonists substituted with unfractionated heparin after 6 wk Vitamin K antagonists substituted with low molecular weight heparin after 6 wk Aspirin throughout pregnancy	No antithrombotic therapy or Other antithrombotic strategy	Maternal thromboembolism Major bleeding maternal death Congenital malformations Fetal/neonatal hemorrhage Pregnancy loss
Treatment PICO Questions
Pregnant women with proven acute VTE	Vitamin K antagonists Unfractionated heparin Low-molecular-weight heparin Other relevant agents	No treatment or Other antithrombotic therapy or Therapy in nonpregnant population with acute VTE	Symptomatic recurrent DVT or pulmonary embolism Fatal pulmonary embolism Major bleeding Postthrombotic syndrome
Pregnant women with proven acute VTE	Throughout pregnancy Throughout pregnancy and 6 wk postpartum (at least 3 mo) Throughout pregnancy and 6 wk postpartum (at least 6 mo) Throughout pregnancy and indefinite postpartum	Other duration	Symptomatic recurrent DVT or pulmonary embolism Fatal pulmonary embolism Major bleeding
Pregnant women with proven acute VTE	Venal caval filter	No vena caval filter	Symptomatic recurrent DVT or pulmonary embolism Fatal pulmonary embolism Major bleeding Postthrombotic syndrome
Pregnant women with proven acute VTE	Elective delivery with discontinuation of antithrombotic therapy 24 to 48 h prior to delivery No elective delivery, transition to unfractionated heparin No elective delivery, transition to prophylactic dose of antithrombotic agent No elective delivery with discontinuation of antithrombotic therapy as soon as labor commences	Other intervention	Symptomatic recurrent DVT or pulmonary embolism Major bleeding: total Epidural hematoma Postthrombotic syndrome

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