VTE

Question 1

What criteria would prompt you to anticoagulate a woman with superficial thrombophlebitis in pregnancy?

Answer 1

Bilateral
Symptoms very distressing
Thrombus < 5 cm from deep venous system
Thrombophlebitis affecting > 5 cm of superficial vein

Question 2

How long must you wait after the last dose of LMWH (for VTE prophylaxis) before neuraxial anesthesia can be offered? What about following the last dose of UH (for prophylaxis)?

Answer 2

10-12 hours after last dose LMWH

Immediately after last dose UH

Question 3

Why is a VQ scan preferred to CT angiography for diagnosis of PE in pregnancy?

Answer 3

Both expose the fetus to radiation levels well below the threshold for increased risk of childhood malignancies
CT angio - iodinated contrast crosses the placenta, theoretical risk of fetal or neonatal hypothyroidism

Question 4

Does UH cross the placenta? Does LMWH?

Answer 4

Neither crosses the placenta - therefore no risk of fetal bleeding, no teratogenicity

Question 5

Under what two circumstances might you consider an IVC filter in pregnancy?

Answer 5

Acute PE within 2 weeks prior to delivery
Anticoagulation is interrupted due to bleeding

(Generally IVC filters are avoided due to the radiation exposure with filter placement)

Question 6

How do you treat ovarian vein thrombosis?

Answer 6

Broad spectrum antibiotics until afebrile & clinically improving x48 hours, therapeutic anticoagulation w/ UH x1-3 months

Little evidence re: risk of recurrence, anticoagulation in subsequent pregnancy not recommended

Question 7

List three high-risk thrombophilias.

Answer 7

High-risk: Antithrombin deficiency, APLAS, homozygous FVL, prothrombin gene mutation, combined thrombophilias

Question 8

What blood test can be used to assess the effects of UH? LMWH?

Answer 8

UH - aPTT

LMWH - factor Xa levels

Question 9

List three indications for therapeutic anticoagulation in pregnancy.

Answer 9

Acute VTE in current pregnancy
Patient on therapeutic anticoagulation prior to pregnancy
Personal history of multiple VTEs
Personal history of VTE and high-risk thrombophilia (antithrombin deficiency, APLAS)

Question 10

List five indications for prophylactic anticoagulation in pregnancy.

Answer 10

Personal history of unprovoked VTE
Personal history of VTE in pregnancy or while using OCP
Personal history of provoked VTE & low-risk thrombophilia
Asymptomatic with known thrombophilia: homozygous FVL, homozygous prothrombin gene mutation 20210A, combined thrombophilia, antithrombin deficiency
Non-obstetrical surgery during pregnancy (depending on surgery, length of hospital stay, etc.)
Strict bedrest >7 days & pre-preg BMI > 25