Module 9

Question 1

What is the preferred LMWH dosing strategy for pregnant women?

Answer 1

LMWH over UFH

BD dosing due to increased creatinine clearance

Question 2

What is the duration of anticoagulation for PE or DVT in pregnant women?

Answer 2

above knee DVT or PE: 6 months total
below knee DVT: 6-8 weeks

must include 6 weeks post-partum

Question 3

What is the management of anticoagulation in the peripartum period?

Answer 3

• W/H 24 hours pre-neuraxial or planed delivery
• Withhold during labor
• Restart 6-12 hours post given no bleeding complications starting at lower dose
• can step up over 48 hours postpartum

Question 4

How do we manage women with VTE <2/52 before delivery?

Answer 4

consider clot burden, maternal/foetal compromise, facilities available

LMWH or UFH with APTT aiming 60-80
May admit for heparin
Minimise pushing
Recommence anticoagulation 4 hours post-op
Thrombolysis if cardiovascular compromise

Question 5

What are the changes in haemostasis and vasculature in pregnancy that increase coagulability?

Answer 5

HAEMOSTASIS

• Increased venous stasis
• Increased FV, FVIII, vWF, fibrinogen
• Decreased fibrinolysis
• Decreased protein S
• Acquired APC resistance

VASCULATURE

• Increased venous capacitance
• Decreased flow
• Decreased venous return
• Increased compression from baby

Question 6

What are some maternal risk factors in the obstetric population for VTE?

Answer 6

• Personal History of VTE
• High BMI
• Family history of VTE
• Age >35
• Ethnicity
• Thrombophilic markers
• Infection
• Smoking
• Varicose veins

Question 7

What are some pregnancy-related risk factors in the obstetric population for VTE?

Answer 7

Hyperemesis
Immobility - 7-10 x risk
Caesarean section
Multiple pregnancy
Multiparity
Preeclampsia
PPH
IVF

Question 8

Which thrombophilia has the greatest relative risk in pregnancy?

Answer 8

antithrombin deficiency

Question 9

In what clinical circumstances do we give both pre and postpartum thromboprophylaxis?

Answer 9

Single unprovoked VTE
VTE on COCP + 1 RF
Provoked extensive DVT/PE
Provoked BK DVT + 1 RF
No VTE but >3 RF

Question 10

In what clinical circumstances are 6/52 postpartum VTE prophylaxis warranted?

Answer 10

Provoked VTE with no RF

> 2 RF

Question 11

What are the options for VTE pharmacoprophylaxis in obstetrics?

Answer 11

LMWH: safe in pregnancy and breastfeeding
Heparin: safe in both

Warfarin: safe in breastfeeding only
DOACs: not safe for either

Question 12

What are the most common presenting signs/symptoms of VTE in pregnancy?

Answer 12

Dyspnoea in 60-70%
70-90% left leg
70-90% iliofemoral
Chest/back pain 66%
Cough 37%
Collapse

Question 13

What is a useful clinical prediction model for DVT in pregnancy?

Answer 13

Left
Equal: leg circumference difference >2cm
FT: first trimester

in combination will detect around 75% of DVT in pregnancy

Question 14

What are the 4 key causes for obstetric haemorrhage (4 Ts)

list some risk factors for each

Answer 14

TONE

• multipary
• prolonged second stage
• fetal macrosomia
• instrumental delivery
• advanced maternal age
• fibroids

TRAUMA

• uterine rupture
• cervical/vaginal/perineal tear
• operative delivery

TISSUE

• retained products
• placenta praevia
• placenta accreta
• abruption

THROMBIN

• thrombocytopenia
• DIC
• hereditary bleeding disorder

Question 15

What are some key laboratory indicators of severe PPH?

Answer 15

plt <50
PT >1.5x upper limit
fibrinogen <2
temp <35
ph <7.2, BE -6, lactate >4
ionised Ca <1.1

Question 16

What differentiates between primary, secondary and major obstetric haemorriage?

Answer 16

PRIMARY
>500ml within first 24 hours

SECONDARY
>500ml 25 hours - 6 weeks

MAJOR
>1000ml

Question 17

What are some key considerations for obstetric management of those with bleeding disorders?

Answer 17

factor levels at booking
factor levels 28-34 weeks
controlled 3rd stage
TXA 10-14 days postpartum 
can give neuraxial anaesthesia >50%
replace with FVIII or IX or DDAVP if levels <50%

Question 18

Are c sections or vaginal births preferred in bleeding disorders?

Answer 18

LUSCS decrease risk of ICH in neonates