VTE, thrombophilia, antithrombotic therapy, and pregnancy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.
BACKGROUND
The use of anticoagulant therapy during pregnancy is challenging because of the potential for both fetal and maternal complications. This guideline focuses on the management of VTE and thrombophilia as well as the use of antithrombotic agents during pregnancy.


METHODS
The methods of this guideline follow the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.


RESULTS
We recommend low-molecular-weight heparin for the prevention and treatment of VTE in pregnant women instead of unfractionated heparin (Grade 1B). For pregnant women with acute VTE, we suggest that anticoagulants be continued for at least 6 weeks postpartum (for a minimum duration of therapy of 3 months) compared with shorter durations of treatment (Grade 2C). For women who fulfill the laboratory criteria for antiphospholipid antibody (APLA) syndrome and meet the clinical APLA criteria based on a history of three or more pregnancy losses, we recommend antepartum administration of prophylactic or intermediate-dose unfractionated heparin or prophylactic low-molecular-weight heparin combined with low-dose aspirin (75-100 mg/d) over no treatment (Grade 1B). For women with inherited thrombophilia and a history of pregnancy complications, we suggest not to use antithrombotic prophylaxis (Grade 2C). For women with two or more miscarriages but without APLA or thrombophilia, we recommend against antithrombotic prophylaxis (Grade 1B).


CONCLUSIONS
Most recommendations in this guideline are based on observational studies and extrapolation from other populations. There is an urgent need for appropriately designed studies in this population.
Department of Medicine, McMaster University and Thrombosis and Atherosclerosis Research Institute, Hamilton, ON, Canada. Electronic address: batesm@mcmaster.ca.
Shannon M
SM
Bates
Faculty of Health and Life Sciences, University of Liverpool, Liverpool, England.
Ian A
IA
Greer
Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands.
Saskia
S
Middeldorp
Department of Pharmacy, University of Washington, Seattle, WA.
David L
DL
Veenstra
Department of Obstetrics and Gynecology, University of Connecticut School of Medicine, Farmington, CT.
Anne-Marie
AM
Prabulos
Medical Department, Innlandet Hospital Trust and Norwegian Knowledge Centre for the Health Services, Gjøvik, Norway.
Per Olav
PO
Vandvik
D000022:Abortion, Spontaneous / Q000097:blood / Q000517:prevention & control; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use; D016736:Antiphospholipid Syndrome / Q000097:blood / Q000150:complications / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D019317:Evidence-Based Medicine; D005260:Female; D005343:Fibrinolytic Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D006493:Heparin / Q000009:adverse effects / Q000627:therapeutic use; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000188:drug therapy* / Q000517:prevention & control*; D012307:Risk Factors; D055502:Secondary Prevention; D012955:Societies, Medical; D019851:Thrombophilia / Q000188:drug therapy*; D054556:Venous Thromboembolism / Q000188:drug therapy* / Q000517:prevention & control*
D000925:Anticoagulants; D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; D006493:Heparin