Heparin-induced thrombocytopenia is rare in pregnancy

OBJECTIVE: The indications for heparin use during pregnancy are expanding; however, heparin is associated with serious adverse effects including hepar in-induced thrombocytopenia. Low-molecular-weight heparin is expensive but is associated with less frequent occurrences of heparin-induced thrombocyto penia in the nonpregnant population. However, the incidence of heparin-indu ced thrombocytopenia during pregnancy is unknown. The purpose of this study was to compare the incidence of heparin-induced thrombocytopenia in pregna nt and nonpregnant women. STUDY DESIGN: This is a retrospective cohort comparison. Pregnant and nonpr egnant women were identified by means of diagnosis related group and Curren t Procedural Terminology code searches at three medical centers in Utah; th e incidence of heparin-induced thrombocytopenia in the two groups was compa red. RESULTS: There were 10 (4%) cases of thrombocytopenia among 244 heparin-tre ated pregnant patients and 26 (11%) cases among the 244 nonpregnant control s. There were no cases of heparin-induced thrombocytopenia in the pregnant group, but there were 10 (4%) cases in the control group (P = .0014). CONCLUSION: Heparin-induced thrombocytopenia is extremely rare in pregnant women.