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Implementing a venous thromboembolism (VTE) risk assessment into a pregnancy advisory service (PAS)

Dr Frederica von HawrylakSpecialty Registrar, Sexual and Reproductive HealthUniversity Hospitals Bristol, UK

VTE in pregnancy

• Relative risk increased 4-6 fold

• Overall incidence1-2/1000

(Diagnosis and Management of deep vein thrombosis in pregnancy BMJ 2017;357:j2344)

VTE in pregnancy

VTE risk increases with gestational age:

• 1st/2nd trimester Small increase

• 3rd trimester 6 x increase

• Up to 6 weeks postnatal 22 x increase

(Sultan AA, West J, Tata LJ, Fleming KM, Nelson-Piercy C, Grainge MJ. Risk of first venous thromboembolism in and around pregnancy: a population-based cohort study. Br J Haematol2012;156:366–73)

MBRRACE - UK

Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the UK

MBRRACE UK Enquiry

VTE is the leading cause of direct maternal death

• 2009 – 2013

• 48 women died from VTE in pregnancy and up to 6 weeks postnatally

• 50% (24) occurred antenatally

• Of which 50% (12) occurred in the 1st trimester

National Guideline

“All women undergoing an abortion should undergo a venous thromboembolism (VTE) risk assessment”

190,406 abortions in England and Wales 2016

(Abortion Statistics, England and Wales:2016. Department of Health (DoH))

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Risk ReductionNICE estimates low molecular weight heparin (LMWH) reduces VTE risk by 60-70%

• Subcutaneous injection daily• Self administered• Dose calculated based on weight• Safe to use in pregnancy, does not cross the placenta

Implementing a VTE proforma

Which women should receive LMWH antenatally?

• All women with a previous VTE

• Women with 4 or more VTE risk factors

(RCOG Guideline, Reducing the Risk of Venous Thromboembolism during pregnancy and the Puerperium, April 2015)

Implementing a VTE proforma

How long do we continue LMWH post procedure?

• Post term delivery • 10 days intermediate risk• 6 weeks high risk

• Post abortion• ?• 7 Days• VTE increases with gestational age• Compliance

VTE Proforma

VTE Proforma

1 ) Procedural Risk Tick Medical procedure and NO previous VTE and NOT expected to have significantly reduced mobility for 3 or more days

Medical procedure and history of previous VTE or expected to have significantly reduced mobility for 3 or more days

Surgical procedure under general anaesthetic/ conscious sedation

Assess thrombosis and bleeding risk (see below)

Assess thrombosis and bleeding risk (see below)

Risk assessment complete – no VTE prophylaxis required (Go to box 8)

VTE Proforma

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VTE Proforma

2) Thrombosis Risk Tick Points Cul. Total

BMI 30-39 1

BMI > 40 2

Personal history of VTE 4

Age >35 1

Smoker 1

Parity ≥3 1

Medical co-morbidities e.g cancer, heart failure, active SLE, inflammatory

disease, nephrotic syndrome, current IV drug user 3

First degree relative with history of VTE 1

Varicose veins with phlebitis 1

Known Thrombophilia - Heterozygous Factor V Leiden or Prothrombin gene

mutation

1

All other Thrombophilias Discuss with doctor

Add points to find total Total

VTE Proforma

VTE Proforma

3) Treatment Outcome Tick Thrombosis risk score 3 points or less

Early mobilisation. No additional prophylaxis

Total score of 4 points or more and no bleeding risk

Early mobilisation/ TEDS Prophylactic Enoxaparin

4) Bleeding Risk Tick Active bleeding/ recent episode of bleeding/ recent stroke Thrombocytopenia (Platelets <75x10⁹/L) Acquired or inherited bleeding disorder Patient currently taking treatment dose anticoagulant

If bleeding risk – discuss with senior/ medical team

VTE Proforma

VTE Proforma

7) Prescription Advice Duration of anticoagulation To commence from day of assessment and to

continue for 7 days post procedure Advice on withholding Enoxaparin for STOP Withhold Enoxaparin for a minimum of 12

hours pre STOP. Can restart post STOP on day of procedure if no concerns re bleeding

Advice on withholding Enoxaparin for MTOP Withhold Enoxaparin on the day of 2nd part/ simultaneous and if there are days when bleeding is heavier than a period

Audit Standards

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Results

• N = 159

• Retrospective case note review

• 39% surgical abortion (38% DoH 2016 data)

Results vs Audit standard

Results

10 patients did not have a VTE risk assessment completed

40%

20%

20%

10%

10% Continued

Phone consultation

Decision uncertain

Booked for surgical

Booked for medical

Results

• 3 women identified as high risk

• 100% correctly identified:• Procedural risk

• VTE risk factors

• Bleeding risk

• LMWH dose

Conclusions

• 94% risk assessed for VTE

• Correctly identifying high risk patients and correctly initiating appropriate management

• VTE form is now part of routine PAS assessment

• Team education on risk assessing women continuing with pregnancy

High risk case study

• 36 year old woman presenting to PAS• 7/40• PMH: Congenital complete heart block, Pacemaker in situ, VTE

Left subclavian 2016• Risk assessment scored 9• Started onto LMWH• Continued with the pregnancy

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Key Message

Women attending PAS are pregnant women and regardless of their chosen outcome for the

pregnancy, their care should include VTE risk assessment, as it does for women attending the

antenatal clinic

QUESTIONS ?With thanks to:

Dr Amanda Clark, Consultant Obstetric Haematologist, University Hospitals Bristol, UKMs Alison Hines, Nursing Manager, Pregnancy advisory service, University Hospitals Bristol, UK