Objective: Safety and efficacy of therapeutic agents used for heparin-induced thrombocytopenia
are not established in pregnancy.
Methods: MEDLINE database was searched in November 2014 to identify all patients who received therapy for HIT
Results: A total of 12 patients with the median age of 28 years (range 21-39) were diagnosed with HIT at the median
gestational age of 20 weeks (range 5-34). Clinical probability (4T) score for HIT was high (50%) or intermediate (50%)
and associated with thrombosis in 50%. Patients were initially managed with lepirudin (33%), argatroban (25%),
danaparoid (25%) or fondaparinux (17%) and ultimately bridged to vitamin K antagonist or maintained on lepirudin. All
patients had resolution of HIT. Complications included therapeutic abortion prior to valve replacement for valve
thrombosis (8%), preterm delivery (18%) and preeclampsia (8%). Except for one instance of hypoplastic lung related to
preterm delivery, none of the other newborns had any complications during delivery.
Conclusion: Confirmed cases of HIT in pregnant patients appear to be rare. Within the limits of retrospective analysis, the
use of argatroban, danaparoid, fondaparinux and lepirudin may be effective in preventing the thrombotic complications of
HIT in pregnancy. The effect of HIT or its therapy on obstetrical complications cannot be determined based on this study
since many of the obstetrical complications are common in otherwise healthy pregnancies. Although this study did not
identify any fetal teratogenicity except hypoplastic lung related to preterm delivery, small number of cases treated with
various therapies precludes any definite conclusion.