Management of Heparin-Induced Thrombocytopenia in Pregnancy

First-Line Treatment for HIT in Pregnancy

Danaparoid is the recommended first-line treatment for pregnant patients with acute or subacute HIT due to its established safety profile and lack of placental transfer 1, 2
In a retrospective case series of 30 pregnant women with acute HIT who received danaparoid, there was no evidence of anti-Xa activity in the umbilical cord blood of the six infants who were checked after delivery 1
Despite the low quality of evidence supporting danaparoid use in pregnancy, the number of patients exposed to this agent and its proven lack of placental transfer make it the current best choice 3, 2

Fondaparinux should be considered only if danaparoid is not available (Grade 2C recommendation) 3, 1
Fondaparinux crosses the placenta in small amounts, with anti-Xa activity detected in umbilical cord blood at approximately one-tenth the concentration in maternal plasma 4
The American Society of Hematology (ASH) guidelines specifically state that fondaparinux is an option for HIT treatment where danaparoid is not available (including in the United States) 5, 6
Experience with fondaparinux in pregnancy remains very limited, especially during the first trimester 5, 6

Caution is advised when administering fondaparinux to patients with renal insufficiency, as it is eliminated by the kidneys 4

For treatment of venous thromboembolism (VTE), fondaparinux is dosed based on weight: 5 mg for patients <50 kg, 7.5 mg for patients 50-100 kg, and 10 mg for patients >100 kg 4
In patients with moderate renal insufficiency (CrCl 30-50 mL/min), the dose of fondaparinux should be reduced by 50% 4
Monitoring is not routinely recommended but can be performed using fondaparinux-specific anti-Xa assays if necessary 4

Unlike heparins, fondaparinux has no specific antidote; recombinant factor VIIa may be effective in cases of uncontrollable bleeding 4