%0 Case Reports %T Two pregnant women with immune-mediated thrombotic thrombocytopenic purpura: A case report. %A Uchida A %A Tanimura K %A Sasagawa Y %A Yamada H %A Katayama Y %A Matsumoto M %J J Obstet Gynaecol Res %V 49 %N 12 %D 2023 Dec 18 %M 37723661 %F 1.697 %R 10.1111/jog.15793 %X Thrombotic thrombocytopenic purpura (TTP) during pregnancy is life-threatening. We encountered two pregnant women with immune-mediated TTP (iTTP). A 40-year-old primigravida woman was referred at 19 gestational weeks (GWs) owing to iTTP. She received plasma exchange (PE) and steroid therapies and delivered a live infant at 27 GWs by cesarean delivery. A 29-year-old primigravida woman was referred owing to intrauterine fetal death and thrombocytopenia at 20 GWs. She was diagnosed with iTTP and received PE therapy. She required additional PE and steroid therapies owing to relapse. Before her second pregnancy, she received prednisolone and hydroxychloroquine according to the therapy for systemic lupus erythematosus (SLE). She had induced labor at 37 GWs owing to decrease plasma level of a disintegrin-like and metalloproteinase with thrombospondin type 1 motif 13 (ADAMTS13) activity. Close monitoring of plasma ADAMTS13 activity level and treatments for underlying SLE may prevent iTTP relapse and lead to a good prognosis.