GTG 37a: reducing risk of VTE in pregnancy and puerperium

Question 1

Antenatal and postnatal VTE risk management of: Previous single unprovoked VTE

Answer 1

Start prophylactic dose LMWH in 1st trimester

Give 6 weeks postpartum

Question 2

Antenatal and postnatal VTE risk management of: Recurrent VTE

Answer 2

LMWH from 1st trimester at an increased dose e.g. 50%, 75% or full treatment dose
Give 6 weeks postpartum

Question 3

Antenatal and postnatal VTE risk management of: Antithrombin deficiency + previous VTE

Answer 3

LMWH from 1st trimester at an increased dose e.g. 50%, 75% or full treatment dose
will need haematology input +/- factor Xa replacement in delivery/labour
Give 6 weeks postpartum

Question 4

Antenatal and postnatal VTE risk management of: Anti-phospholipid syndrome + previous VTE

Answer 4

LMWH from 1st trimester at an increased dose e.g. 50%, 75% or full treatment dose
Give 6 weeks postpartum

Question 5

Antenatal and postnatal VTE risk management of: Single provoked VTE with no other risk factors

Answer 5

Start prophylactic dose LMWH at 28 weeks

Monitor carefully for other risk factors

Give 6 weeks postpartum

Question 6

Antenatal and postnatal VTE risk management of:
No VTE + antithrombin deficiency or protein C deficiency, protein S deficiency or homozygous factor V leiden, homozygous prothrombin gene mutation, compound heterozygote

Answer 6

Refer to expert

Consider antenatal prophylaxis

Give 6 weeks postpartum

Question 7

Antenatal and postnatal VTE risk management of:

No VTE+ antiphospholipid antibodies, heterozygous factor V leiden, heterozygous prothombin gene mutation

Answer 7

If 3 additional risk factors give prophylactic dose LMWH from 1st trimester

If 2 additional risk factors give prophylactic dose LMWH from 28/40

If 1 additional risk factor give postnatal 10 days of LMWH

Unless family history of VTE – then give 6 weeks postpartum

Question 8

Antenatal and postnatal VTE risk management of:

4 antenatal risk factors e.g. BMI 35, IVF pregnancy, age 40, Para 4

Answer 8

Give prophylactic dose LMWH from first trimester

Give 6 weeks postpartum

Question 9

Antenatal and postnatal VTE risk management of:

3 antenatal risk factors e.g. BMI 35, IVF pregnancy, age 41

Answer 9

Give prophylactic dose LMWH from 28 weeks

Give 6 weeks postpartum

Question 10

Antenatal and postnatal VTE risk management of:

2 postpartum risk factors e.g. BMI 35, age 37

Answer 10

Does not require antenatal LMWH Give 10 days LMWH postpartum

Question 11

Antenatal and postnatal VTE risk management of: Admission to hospital in pregnancy

Answer 11

Give LMWH unless contraindicated

Question 12

Antenatal and postnatal VTE risk management of: Major surgery in pregnancy

Answer 12

Assess other risk factors but consider course of LMWH unless contraindicated

Question 13

Antenatal and postnatal VTE risk management of: Ovarian hyperstimulation syndrome

Answer 13

Consider LMWH – give if severe or critical OHSS. Higher risk is late onset or pregnant – continue for duration of 1st trimester

Question 14

Antenatal and postnatal VTE risk management of: Hyperemesis

Answer 14

Give LMWH unless contraindicated until hyperemesis has resolved

Question 15

Antenatal and postnatal VTE risk management of:

BMI >40

Answer 15

As a risk factor alone – does not require LMWH antenatally

Counts as 2 risk factors postnatally therefore for if no additional risk factors – 10 days LMWH

Question 16

Needs a spinal/epidural (on prophylactic dose LMWH)

Answer 16

Stop LMWH 12 hours before

Question 17

Needs a spinal/epidural (on treatment dose LMWH)

Answer 17

Stop LMWH 24 hours before

Question 18

Postpartum and had a spinal

Answer 18

Restart LMWH >4 hours after spinal

Question 19

Postpartum and had an epidural

Answer 19

Remove catheter >12 hours after last dose of LMWH

Question 20

Postpartum VTE risk management:

Emergency c-section

Answer 20

Counts as 2 postnatal risk factors – give 10 days if no additional risk factors

Question 21

Postpartum VTE risk management:

Pre-clampsia, mid-cavity forceps, preterm delivery 36+2/40, PPH 1.5litres

Answer 21

4 risk factors – needs LMWH for 6 weeks postpartum

Question 22

What proportion of fetuses develop warfarin embryopathy?

Answer 22

5%

Question 23

What are the features of warfarin embryopathy?

Answer 23

Hypoplasia of nasal bridge 
Congenital heart defects 
Ventriculomegaly 
Stipled epiphyses 
Agenesis of the corpus callosum

Question 24

What is danaparoid?

Answer 24

Heparinoid used under advisement by a haematologist for patients who have had HIT or skin reaction to heparin
Safe in breastfeeding

Question 25

What is fondaparinux?

Answer 25

Synthetic pentasaccharide
Inhibition of Factor Xa (antithrombin)
Used in patients intolerant to heparin

Question 26

What is the half life of danaparoid?

Answer 26

24 hours

Question 27

What is the half life of fondaparinux?

Answer 27

18 hours

Question 28

What is the incidence of PE in pregnancy?

Answer 28

1.3 in 100,000 maternities

Question 29

What is the incidence of DVT in pregnancy and puerperium?

Answer 29

107 in 100,000 maternities

Question 30

What is the recurrence rate of VTE in subsequent pregnancies?

Answer 30

2-11%

Question 31

What proportion of pregnancy VTE cases are associated with a heritable thrombophilia?

Answer 31

20-50%

Question 32

Outside of pregnancy, by how much is the VTE risk in women 35 and older is increased?

Answer 32

50%

Question 33

In the postpartum, by how much is the VTE risk in women 35 and older is increased?

Answer 33

70%

Question 34

How much does being pregnant increase your risk of VTE?

Answer 34

2-6x increased risk

Question 35

How much is risk of VTE increased by being an inpatient?

Answer 35

18 x increased risk of VTE

Question 36

How much is VTE risk increased in the postpartum compared to antenatal period?

Answer 36

5 x increased risk of VTE