Use of recombinant human antithrombin concentrate in pregnancy

Abstract

Dear editor We read with great interest James et al’s article “Prevention and treatment of venous thromboembolism in pregnancy in patients with hereditary antithrombin deficiency.” The authors reported a case series of six women with antithrombin (AT) deficiency treated with plasma derived antithrombin concentrate (pdAT; Thrombate III®, Grifols Therapeutics, Clayton, NC, USA).1 In contrast to these cases, we have managed three AT-deficient women over the past two years with low-molecular-weight-heparin during pregnancy and recombinant human antithrombin concentrate (rhAT; ATryn®, GTC Biotherapeutics, Framingham, MA, USA) at delivery. In the Phase III trial leading to approval of rhAT, pregnant women required frequent dose modifications, and an alternate dosing regimen is currently recommended by the manufacturer.2,3 The detailed information provided in these cases may assist future providers in managing pregnant patients with AT deficiency.