VTE Pregnancy

Question 1

Physiological changes in pregnancy with coagulable state

Answer 1

Physiological hypercoagulable state
Increase in factor 8,9,10
Fibrinogen rises by 50%
Decreased fibrinolytic activity

Endogenous anticoagulants like protein S and antithrombin fall

This risk is present from the T1 and to 12 weeks post partum

APTT is normal

Vasodilation in the lower limbs, Decreased flow L>R due to compression of the L iliac vein by the R iliac artery + ovarian artery

Question 2

What is the highest direct cause of maternal mortality in the UK

Answer 2

PE

Kills 5-10 woman/ year

Question 3

When is the greatest risk for VTE

Answer 3

Post partum

Question 4

How much is the risk of VTE increased compared to the general population

Answer 4

6X increased risk

This is doubles if you have an ElLSCS

EMLSCS doubles the risk compared to an ELLSCS

Question 5

What is the actual risk of VTE after a caesarean?

Answer 5

1-2%

Question 6

Which leg

Answer 6

90% L side
increased risk venous stasis
iliofemoral is much more common then in the non pregnant patient

Question 7

clinical assessment for VTE

Answer 7

Not reliable
clinical judgement will be wrong in 30-50% of cases in pregnancy
oedema and leg pain are common in pregnancy without VTE

Question 8

What are the exam signs of PE

Answer 8

Tachycardia
Tachypnoea
Raised JVP
Loud second heart sound
R ventricular heave

If there is pulmonary infarction a fever and pleural rub may be present

Question 9

Risk factors for VTE

Answer 9

Thombophilia 
Heritable 
Anti thombin deficiency
Protein C or S deficinecy
Factor V leiden
Prothrombin gene G20210A

Acquired
Anti phospholipid syndrome
Persistent high antibodies

medical comorbidities: Cancer, HF, SLE, IBD/joint disease nephrotic syndrome, T1DM with nephropathy, sickle cell disease, IVDU 
Age over 35
P3
BMI over 30
Gross varicose veins 
Paraplegia

Pregnancy related
Multiple pregnancy
Current PET
LSCS
Prolonged labour
Midcavity rotational operative delivery
still birth
preterm birth
PPJ over 1 L or requiring transfusion 

Transient factors
Hyperemesis and dehyration
Surgical procedure in pregnancy
Overian hyperstimulation
Admission / immobility
Systemic infection req antibiotics or admission
Long distance travel - over 4 hours

Question 10

What investigations are needed for the diagnosis of an acute DVT?

Answer 10

Compression duplex ultrasound should be undertaken where there is clinical suspicion of DVT.
If ultrasound is negative and there is a low level of clinical suspicion, anticoagulant treatment can
be discontinued. If ultrasound is negative and a high level of clinical suspicion exists, anticoagulant
treatment should be discontinued but the ultrasound should be repeated on days 3 and 7.

Question 11

What investigations are needed for the diagnosis of an acute pulmonary embolism (PE)?

What does the ECG show?

What does the CXR show?

Answer 11

Women presenting with symptoms and signs of an acute PE should have an electrocardiogram
(ECG) and a chest X-ray (CXR) performed.

ECG
R axis deviation
RBBB
Peaked T waves in lead 2
S1Q3T3 can be normal in pregnancy - not reliable 
CXR - areas of translucency in underperfused lung
Atelectasis
Wedge shaped infarction
Pleural effusion

Question 12

What if sx of PE and DVT - what test?

Answer 12

In women with suspected PE who also have symptoms and signs of DVT, compression duplex
ultrasound should be performed. If compression ultrasonography confirms the presence of DVT,
no further investigation is necessary and treatment for VTE should continue.

In women with suspected PE without symptoms and signs of DVT, a ventilation/perfusion (V/Q) lung
scan or a computerised tomography pulmonary angiogram (CTPA) should be performed.

Question 13

If the CXR is abnormal - what Ix is best next in PE work up ?

Answer 13

When the chest X-ray is abnormal and there is a clinical suspicion of PE, CTPA should be performed
in preference to a V/Q scan.

Question 14

Compare and contract CTPA with VQ scanning

Answer 14

Women with suspected PE should be advised that, compared with CTPA, V/Q scanning may carry
a slightly increased risk of childhood cancer but is associated with a lower risk of maternal breast cancer; in both situations, the absolute risk is very small.

Where feasible, women should be involved in the decision to undergo CTPA or V/Q scanning.
Ideally, informed consent should be obtained before these tests are undertaken.

Question 15

What baseline blood investigations should be performed before initiating anticoagulant therapy?

Answer 15

Before anticoagulant therapy is commenced, blood should be taken for a full blood count,
coagulation screen, urea and electrolytes, and liver function tests.
Performing a thrombophilia screen prior to therapy is not recommended.

Question 16

What is the initial treatment of VTE in pregnancy?

Answer 16

In clinically suspected DVT or PE, treatment with low-molecular-weight heparin (LMWH) should be
commenced immediately until the diagnosis is excluded by objective testing, unless treatment is
strongly contraindicated.

LMWH should be given in doses titrated against the woman’s booking or early pregnancy weight.
There is insufficient evidence to recommend whether the dose of LMWH should be given once daily or in two divided doses.
There should be clear local guidelines for the dosage of LMWH to be used.

Question 17

How do monitor heparin levels?

Answer 17

Routine measurement of peak anti-Xa activity for patients on LMWH for treatment of acute VTE in pregnancy or postpartum is not recommended except in women at extremes of body weight
(less than 50 kg and 90 kg or more) or with other complicating factors (for example, with renal
impairment or recurrent VTE).
Routine platelet count monitoring should not be carried out.

Question 18

How should massive life-threatening PE in pregnancy and the puerperium be managed?

Answer 18

Collapsed, shocked women who are pregnant or in the puerperium should be assessed by a team
of experienced clinicians including the on-call consultant obstetrician.
Women should be managed on an individual basis regarding: intravenous unfractionated heparin,
thrombolytic therapy or thoracotomy and surgical embolectomy.
Intravenous unfractionated heparin is the preferred, initial treatment in massive PE with cardiovascular compromise.
The on-call medical team should be contacted immediately.
An urgent portable echocardiogram or
CTPA within 1 hour of presentation should be arranged. If massive PE is confirmed, or in extreme circumstances prior to confirmation, immediate thrombolysis should be considered.

Question 19

Should graduated elastic compression stockings be employed in the acute management of VTE in pregnancy?

Answer 19

In the initial management of DVT, the leg should be elevated and a graduated elastic compression
stocking applied to reduce oedema. Mobilisation with graduated elastic compression stockings
should be encouraged

Question 20

What is the role of inferior vena cava filters in the management of VTE in pregnancy?

Answer 20

Consideration should be given to the use of a temporary inferior vena cava filter in the peripartum
period for patients with iliac vein VTE to reduce the risk of PE or in patients with proven DVT and
who have recurrent PE despite adequate anticoagulation.

Question 21

What is the maintenance treatment of DVT or PE?

Answer 21

Treatment with therapeutic doses of subcutaneous LMWH should be employed during the remainder
of the pregnancy and for at least 6 weeks postnatally and until at least 3 months of treatment has
been given in total.

Women should be taught to self-inject LMWH and arrangements made to allow safe disposal of
needles and syringes. Outpatient follow-up should include clinical assessment and advice with
monitoring of blood platelets and peak anti-Xa levels if appropriate

Question 22

Should anticoagulant therapy be altered during labour and delivery?

Answer 22

The woman on LMWH for maintenance therapy should be advised that once she is in established
labour or thinks that she is in labour, she should not inject any further heparin.

Where delivery is planned, either by elective caesarean section or induction of labour, LMWH
maintenance therapy should be discontinued 24 hours prior to planned delivery.

Regional anaesthetic or analgesic techniques should not be undertaken until at least 24 hours
after the last dose of therapeutic LMWH.

LMWH should not be given for 4 hours after the use of spinal anaesthesia or after the epidural
catheter has been removed, and the epidural catheter should not be removed within 12 hours of the most recent injection.

Question 23

Are specific surgical measures required for anticoagulated patients undergoing delivery by caesarean
section?

Answer 23

In patients receiving therapeutic doses of LMWH, wound drains (abdominal and rectus sheath)
should be considered at caesarean section and the skin incision should be closed with interrupted
sutures to allow drainage of any haematoma.

Question 24

What anticoagulant therapy should be employed in women at high risk of haemorrhage?

Answer 24

Any woman who is considered to be at high risk of haemorrhage, and in whom continued heparin
treatment is considered essential, should be managed with intravenous unfractionated heparin
until the risk factors for haemorrhage have resolved.

Question 25

How should anticoagulation be managed postnatally?

Answer 25

Therapeutic anticoagulant therapy should be continued for the duration of the pregnancy and for at least 6 weeks postnatally and until at least 3 months of treatment has been given in total. Before discontinuing treatment the continuing risk of thrombosis should be assessed. Women should be offered a choice of LMWH or oral anticoagulant for postnatal therapy after discussion about the need for regular blood tests for monitoring of warfarin, particularly during the first 10 days of treatment. Postpartum warfarin should be avoided until at least the fifth day and for longer in women at increased risk of postpartum haemorrhage. Both ok for breast feeding

Question 26

What measures can be employed to prevent the development of post-thrombotic syndrome?

Answer 26

Women should be advised that prolonged use of LMWH (more than 12 weeks) is associated with a significantly lower chance of developing post-thrombotic syndrome Following a DVT, graduated elastic compression stockings should be worn on the affected leg to reduce pain and swelling. Clinicians should be aware that the role of compression stockings in the prevention of post-thrombotic syndrome is unclear

Question 27

What is post thrombotic syndrome and what increases its risk ? What is the rate?

Answer 27

A chronic persistent leg swelling, pain, a feeling of heaviness, dependant cyanosis, telangiectasis, chronic pigmentation, eczema, associated varicose veins and in the most severe cases, venous ulceration. A case–control study from Norway found a prevalence of PTS of 42% following DVT in pregnancy; proximal postnatal thrombosis, smoking and age greater than 33 years were independent predictors of the development of PTS

Question 28

When to assess the risk:

Answer 28

All women should undergo a documented assessment of risk factors for VTE in early pregnancy or prepregnancy. Risk assessment should be repeated if the woman is admitted to hospital for any reason or develops other intercurrent problems Risk assessment should be repeated again intrapartum or immediately postpartum.

Question 29

How to manage multiple risk factors?

Answer 29

4 or more should be considered for prophylactic low-molecular-weight heparin (LMWH) throughout the antenatal period and will usually require prophylactic LMWH for 6/52 PN (with PN risk assessment) 3 current risk factors = prophylactic LMWH from 28 weeks and usually required for 6 weeks PN (with PN risk assessment) 2 current RF = LMWH for 10 days post partum

Question 30

How should women with previous VTE be managed in pregnancy?

Answer 30

Prepregnancy counselling and a prospective management plan. Those who become pregnant before receiving such counselling should be referred at the earliest opportunity Women with previous VTE (except those with a single previous VTE related to major surgery and no other risk factors) should be offered thromboprophylaxis with LMWH throughout the antenatal period Women with previous VTE should have a careful history documented. Where objective documentation is not available, the previous diagnosis of VTE can be assumed in cases where the woman gives a good history and received prolonged (greater than 6 weeks) therapeutic anticoagulation.

Question 31

How to manage Heritable thrombophilia in pregnancy | with previous VTE

Answer 31

Women with previous VTE associated with antithrombin deficiency (who will often be on long-term oral anticoagulation) should be offered thromboprophylaxis with higher dose LMWH (either 50%, 75% or full treatment dose) antenatally and for 6 weeks postpartum or until returned to oral anticoagulant therapy after delivery. MDT approach Consideration given to antenatal anti-Xa monitoring +/- antithrombin replacement at initiation of labour or prior to caesarean section If anti-Xa levels are measured, a test that does not use exogenous antithrombin should be used and 4-hour peak levels of 0.5–1.0 iu/ml aimed for Other heritable thrombophilic defects are lower risk and can be managed with standard doses of thromboprophylaxis

Question 32

How to manage Women with VTE associated with the antiphospholipid syndrome

Answer 32

should be offered thromboprophylaxis with higher dose LMWH (either 50%, 75% or full treatment dose) (see Appendix IV) antenatally and for 6 weeks postpartum or until returned to oral anticoagulant therapy after delivery Pregnant women with APS and prior VTE or arterial thromboses should be managed in collaboration with a haematologist and/or rheumatologist with expertise in this area.

Question 33

What extra advice is needed for women with previous recurrent VTE?

Answer 33

Advice regarding doses of LMWH in pregnancy should be sought from a clinician with expertise in haemostasis and pregnancy Some women with previous recurrent VTE require higher doses of LMWH Women not on warfarin or other oral anticoagulants should be advised to start LMWH as soon as they have a positive pregnancy test

Question 34

How to manage woman on long term warfarin?

Answer 34

Women on long-term warfarin or other oral anticoagulants should be counselled about the risks of these agents to the fetus and advised to stop their oral anticoagulant therapy and change to LMWH as soon as pregnancy is confirmed, ideally within 2 weeks of the missed period and before the sixth week of pregnancy.

Question 35

Previous VTE: summary of how to stratify risk Who gets high dose / treatment dose WHo gets prophylaxis throughout Who can start at 28 weeks?

Answer 35

Highest risk: Women with VTE + + antithrombin deficiency + APS + with recurrent VTE (who will often be on long-term oral anticoagulation) = higher dose LMWH (either 50%, 75% or full treatment dose antenatally and for 6/52 PP OR until on oral anticoagulant again Manage MDT - haematologists Medium risk original VTE was unprovoked/idiopathic or related to OCP or related to a transient risk factor (other than major surgery) or who have other risk factors LMWH throughout the antenatal period. Lower risk In women in whom the original VTE was provoked by major surgery from which they have recovered and who have no other risk factors, thromboprophylaxis with LMWH can be withheld antenatally until 28 weeks provided no additional risk factors are present (in which case they should be offered LMWH). They require close surveillance for the development of other risk factors.

Question 36

Which women with prior VTE require thrombophilia testing?

Answer 36

Anyone on it antenatally Previous VTE thrombophilia Anti Phospholipid Prior to testing for thrombophilia, women should be counselled regarding the implications for themselves and family members of a positive or negative result. The results should be interpreted by clinicians with specific expertise in the area. Women with a family history of VTE and either antithrombin deficiency or where the specific thrombophilia has not been detected should be tested for antithrombin deficiency. Women with an unprovoked VTE should be tested for the presence of antiphospholipid antibodies

Question 37

Post natal prophylaxis

Answer 37

BMI over 40 – should have 10/7 LMWH 2 or more risk factors should have 10/7 LMWH EMLSCS 10/7 LWMH ELLSCS +1 RF = 10/7 LWMH Additional risks = 6/52 Wound infection surgery Prolonged admission

Question 38

Intrapartum management of LMWH

Answer 38

If any bleeding or labour – stop clexane Reginal anaesthetic should wait 12 hours after prophylactic dose Should not be given until 4 hours after a spinal or catheter removal The catheter should not be removed within 12 hours of an injection

Question 39

Early pregnancy risks for VTE and how to reduce them

Answer 39

OHSS - clexane throughout T1 Hyperemesis + admission = clexane until hyperemesis resolves IVF is a risk factor to add in