Prevention of Venous Thrombo-Embolism

1. PREVENTION OF VTE IN
OBSTETRIC POPULATION
BY Dr Kanddy Loo
O&G Updates
1/11/14
O&G department
Miri hospital

2. CASE SCENARIO
• 40 year-old P6, post emergency caesarean
section for acute fetal distress D 6
• Had BMI of 40
• Presented with acute onset of SOB and chest
pain
• Denied calf swelling
• Otherwise, no known medical illness;
normotensive antenatally and intrapartumly
• Examination showed tachycardia and
tachypnoea; with saturation under room air of
80%; normotensive
• Lungs examination was unremarkable

3. PROBABLE DIAGNOSIS…..

4. INTRODUCTION
• Pulmonary embolism remains the leading direct cause of maternal death
• Most of the patients who died from PE have identifiable risks
• 70% of women who died from PE in UK between 2003-2005 had identifiable risk
• Thromboprophylaxis antenatally and postnatally – estimated to reduce risk of
VTE in obstetric patients by up to 2/3
• Objective of this lecture
• Introduction of state VTE prevention programme
• Risk stratification of patient according to VTE score to identify patients for
thromboprophylaxis
• Antenatal VTE occur in the first trimester
• Therefore assessment and prophylaxis, if indicated should be given as early as
possible in pregnancy

5. MATERNAL MORTALITY - UK
CEMACH 2003-2005 CEMACH 2006-2008

6. MATERNAL MORTALITY - MALAYSIA

7. PATHOPHYSIOLOGY
• Incidence of VTE in pregnancy – 60/100000
woman-years
• 12 fold increase compared to non pregnant
population
• Virchow’s Triad

9. SARAWAK VTE PREVENTION PROGRAMME
• Introduced on 1 July 2013
• To be implemented over Sarawak state
• Initially hospital based
• Expanded to primary health care centre on Mac 2014
• Obstetric patients are assessed based on modified VTE scoring system
• Done as early in pregnancy as possible
• Repeat assessment if there’s emergence of new risk factors/during hospitalisation
• Start thromboprophylaxis if
• VTE score 3 or more antenatally and continue postnatally for 6 weeks
• VTE score 2 or more postnatally – for at least 1 week
• Patient with additional persistent risk factor (lasting more then 1/52 postnatal) should
thromboprophylaxis should be extended for up to 6 weeks or longer

11. VERY HIGH VTE RISK
• Needs antenatal high-dose thromboprophylaxis (high prophylactic – 12
hourly or 75% of treatment dose) antenatally and postnatally 6 weeks
• Very high risk factors
• Recurrent VTE associated with APS
• Patient on long term anticoagulation
• Antithrombin deficiency

12. HIGH RISK
• Thromboprophylaxis antenatally and 6 weeks postnatally
• Risk factors
• Previous unprovoked, estrogen related (pregnancy/pills induced), recurrent VTE
• Previous VTE with risk factors (family history of VTE, thrombophyilia or other risk
factors
• Asymptomatic thrombophilia (combine defects, homozygous Factor V Leiden)
• Combination of 3 or more risk factors

13. INTERMEDIATE RISK
• Postnatal thromboprophylaxis (duration ranges from 1 – 6 weeks)
• Single previous VTE associated with temporary risk factor with no other risk
factors (thromboprophylaxis upto 6 weeks postnatal)
• Asymptomatic thrombophilia (except antithrombin deficiency, combined
defects, homozygous FVL) – 1 week prophylaxis or 6 weeks if presence of
other risk factors
• Presence of 2 or more risk factors

14. THROMBOPHILIA SCREENING
• Only done for those VTE provoked by minor risk factors
• Antenatal thromboprophylaxis till postnatal 6/52
• Previous VTE with thromphilia
• Asymptomatic thrombophilia with other risk factors
• Asymptomatic thrombophilia
• Combine defects
• Homozygous Factor V Leiden
• Postnatal thrombophylaxis
• Other asymptomatic thrombophilia without other risk factors

15. ANTI COAGULANT AGENTS
• Low molecular weight heparin
• Agents of choice
• As effective as and safer then the unfractionated heparin
• Lower risk of Heparin induced thrombocytopaenia and osteoporosis
• Risk of bleeding - <2% with prophylactic dose
• Monitoring of anti-Xa levers is not required if women have normal renal function
• Unfractionated Heparin
• Shorter half life
• More complete reversal of its activity
• May be used around the time of delivery in women with very high risk of
thrombosis

16. • Fondaparinox
• Licenced for prevention and treatment of VTE outside pregnancy
• Similar efficacy to LMWH
• Limited experience in pregnancy
• Although no adverse effects were observed in newborns, it is premature to conclude its safety in pregnancy
• Reserved for women intolerance to heparin
• Local setting – used in postnatal thrombophylaxis
• Warfarin
• Associated with warfarin embriopathy
• 5% risk when exposed between 6 – 12 weeks
• For patient with mechanical heart valve
• Can be used postnatally – 5 – 7 days post delivery
• Safe in breastfeeding
• Other anti coagulant – avoided in pregnancy
• Graduated elastic compression stocking

18. CONTRAINDICATION TO THROMBOPROPHYLAXIS
• Antenatal or postpartum bleeding
• Massive PPH – risk factor for VTE; therefore risk and benefits of
thromboprophylaxis should be weighted
• Increased risk of major haemorrhage
• Bleeding diathesis, including thrombocytopaenia
• Platelet less than 75 x 109
• Acute stroke in last 4 weeks
• Severe renal disease
• Severe liver disease
• Uncontrolled hypertension (SBP>200mmHg; DBP>120mmHg)

19. ANAESTHESIA
• Regional techniques should not be used at least 12 hours after previous
prophylactic dose of LMWH
• 24 hours after last dose of therapeutic dose
• 4 hours after last dose of unfractionated heparin
• LMWH should not be given for 4 hours after regional anaesthesia or after
removal of epidural catheter
• Epidural catheter should not be removed within 10 – 12 hours of the last dose

20. QUIZ – SCENARIO 1
• 40 year-old; primigravida; subfertility for 20 years
• BMI 32
• Currently at 10 weeks…..

21. • At 12 weeks, she was admitted with hyperemesis gravidarum….
• At 30 weeks, she was again admitted and treated as acute appendicitis;
appendicectomy was done

22. • At 38 weeks, she has EMLSCS for fetal compromise; complicated with
massive PPH and had massive transfusion….

23. QUIZ – SCENARIO 2
• 30 year-old G2P1 at 8 weeks; came for booking
• Previous history of postpartum DVT; completed warfarin treatment for 6
months
• Currently well, no leg swelling
• BM1 25

24. • At 36 weeks, she presented with SROM with TMSL and os was only 1 cm….
• Postnatally….

25. THANK YOU