This document summarizes guidelines for assessing and managing the risk of venous thromboembolism (VTE) during pregnancy and postpartum. It discusses the increased risk of VTE during this time period and identifies major risk factors. Guidelines are provided for testing and treatment based on a patient's VTE risk profile, including recommendations for anticoagulation with low molecular weight heparin or unfractionated heparin during pregnancy and postpartum. Considerations for regional anesthesia and procedures are also addressed.

1. VTE Pregnancy Kami M. Dixon, MD October 2011

12. THE UGLY ACOG PB # 124, September 2011 THE UGLY Prevalence in the general population % VTE RISK per Pregnancy (No History) % VTE RISK per Pregnancy (Prev VTE) % Percentage of ALL VTE % ATIII Deficiency <60% 0.02 3 - 7 40 1 FVL Homozygous <1 1.5 17 2 PTGM G20210A Homozygous <1 2.8 >17 0.5 PTGM G20210A + FVL Compound Heteroz 0.01 4.7 >20 1 - 3

13. THE BAD ACOG PB # 124, September 2011 THE BAD Prevalence in the general population % VTE RISK per Pregnancy (No History) % VTE RISK per Pregnancy (Prev VTE) % Percentage of ALL VTE % FVL Heterozygous 1 – 15 <0.3 10 40 PTGM G20210A Heterozygous 2 – 5 <0.5 >10 17 Protein C Activity <60% 0.2 – 0.4 0.1 – 0.8 4 – 17 14 Protein S free antigen <55% 0.03 – 0.13 0.1 0-22 3

14. THE NOT SO GOOD ACOG PB # 124, September 2011 Not Good Prevalence in the general population % VTE RISK per Pregnancy (No History) % VTE RISK per Pregnancy (Prev VTE) % Percentage of ALL VTE % MTHFR C677T MTHFR A1298C 10 – 16% Euro 4 – 6% Euro No increased risk Weak N/A PTGM G20210A Heterozygous 2 – 5 <0.5 >10 17 Protein C Activity <50% 0.2 – 0.4 0.1 – 0.8 4 – 17 14 Protein S free antigen <55% (non-preg) or <30% in 2 nd Tri, or <24% in 3rd 0.03 – 0.13 0.1 0-22 3

16. How to TEST ACOG PB # 124, September 2011 Thrombophilia Testing Method Reliable During Pregnancy? Reliable with Acute Thrombosis? Reliable with Anticoagulation? Antithrombin III Deficiency Antithrombin activity <60% YES NO NO Factor V Leiden Mutation Activated Protein C resistance assay If Abnormal: DNA Analysis YES YES YES YES NO YES PTGM G20210A Heterozygous DNA ANALYSIS YES YES YES Protein C Deficiency Activity <60% YES NO NO Protein S Deficiency free antigen <55% (non-preg) or <30% in 2 nd Tri, or <24% in 3rd YES NO NO

17. WHO: PREVIOUS VTE & Prevention ANTEPARTUM TX POSTPARTUM TX LOW RISK Temporary RF NO Thrombophilia Surveillance WITHOUT anticoagulation Prophylactic Lovenox up to 6 weeks MODERATE RISK LRThrombophilia w single VTE-not on long term tx : FVLHet, PTGHet, Prot C/S Prophylactic or Intermediate Dose Lovenox (or surveillance ) Prophylactic Lovenox 6 weeks post partum MODERATE RISK Idiopathic Obesity Pregnancy or estrogen Related APA (+/- ASA) Prophylactic or Intermediate Dose Lovenox Prophylactic Lovenox 6 weeks post partum ELEVATED RISK HR Thrombophilia w single VTE-not on long term tx: ATIII, Dbl heteroz PTGM/FVL, FVL homoz, PTGM homoz, or persistent APL abs Intermediate or Adjusted dose (Therapeutic) Lovenox for 6 weeks Intermediate or Adjusted dose (Therapeutic) Lovenox for 6 weeks

18. WHO: PREVIOUS VTE & Prevention PP treatment should be greater or equal to antepartum treatment ACOG supports therapy using either LMWH or UFH ANTEPARTUM TX POSTPARTUM TX ELEVATED RISK 2+ VTE Thrombophilia or no thrombophilia NOT ON LONG TERM THERAPY Intermediate or Adjusted dose (Therapeutic) Lovenox (ACOG- prophylactic or therapeutic) Intermediate or Therapeutic Lovenox for 6 weeks HIGHEST RISK 2+ VTE Thrombophilia or no thrombophilia ON LONG TERM THERAPY Mechanical heart valve Therapeutic Dose Resume long-term anticoagulation therapy

19. WHO: NO VTE BUT OTHER RF PP treatment should be greater or equal to antepartum treatment ACOG supports therapy using either LMWH or UFH ANTEPARTUM TX POSTPARTUM TX Low Risk Low-risk thrombophilia without previous VTE FVLHet, PTGHet, Prot C/S def APA w/o VTE Prophylactic Lovenox (ACOG-OR surveillance) Prophylactic or surveillance + ASA Prophylactic 6 weeks Lovenox (ACOG if additional RF-1 st degree relative, obesity, immobility etc; surveillance ok w acog) Moderate Risk High-risk thrombophilia NO h/o VTE ATIII, Dbl heteroz PTGM/FVL, FVL homoz, PTGM homoz, or persistent APL abs Prophylactic Lovenox Prophylactic 6 weeks Lovenox

29. Dr. Can I have an Epidural? Resume therapy 4-6 hours after NSVD or 6-12 hours after C/S. ASRA DO NOT RESUME LMWH SOONER THAN 2 hours after removal of catheter Regional Anesthesia and Pain Medicine: Vol 35, No1, Jan-Feb 2010 Thanks Dr. LaValle Warfarin INR <1.5 (stop 4-5 days prior to procedure) Heparin full dose IV aPTT <40 Lovenox full dose Wait 24 hours Lovenox prophylactic dose Wait 12 hours Heparin prophylactic dose >5000 sq aPTT <40 Heparin prophylactic dose 5000 bid/tid Wait 1 hour ASA/NSAIDS NOW