gynecology and obstetrics
Autoimmune Disorders in Pregnancy
Immune Thrombocytopenia in Pregnancy
 Immune Thrombocytopenia (ITP) , mediated by maternal antiplatelet IgG, tends to worsen during pregnancy and increases risk of maternal morbidity. ITP is characterized by isolated thrombocytopenia in the absence of other etiologies, making it a diagnosis of exclusion. Corticosteroids reduce IgG levels and cause remission in most women, but improvement is sustained in only 50%. Immunosuppressive therapy and plasma exchange further reduce IgG, increasing platelet counts. Rarely, splenectomy is required for refractory cases; it is best done during the 2nd trimester, when it causes sustained remission in about 80%. IV immune globulin increases platelet count significantly but briefly, so that labor can be induced in women with low platelet counts. Platelet transfusions are recommended only when Cesarean delivery is required and maternal platelet counts are < 50,000/microL ( References ). Vaginal delivery is expected and maternal platelet counts are < 30,000/microL ( References ). Although antiplatelet IgG can cross the placenta, it only very rarely causes fetal or neonatal thrombocytopenia. Maternal antiplatelet antibody levels (measured by direct or indirect assay) cannot predict fetal involvement. Risk of neonatal intracranial hemorrhage due to maternal ITP is not affected by the mode of delivery nor by birth trauma. Accordingly, the current accepted practice is vaginal delivery, without routinely determining the fetal platelet count, and cesarean delivery only for obstetric indications ( References , 1.Kaufman RM, Djulbegovic B, Gernsheimer T, et al: Platelet transfusion: a clinical practice guideline from the AABB.Ann Intern Med162(3):205-213, 2015. doi:10.7326/M14-1589 2.Bussel JB, Hou M, Cines DB: Management of primary immune thrombocytopenia in pregnancy.N Engl J Med389(6):540-548, 2023. doi:10.1056/NEJMra2214617 3.ACOG Practice Bulletin No. 207: Thrombocytopenia in Pregnancy.Obstet Gynecol133(3):e181-e193, 2019. doi:10.1097/AOG.0000000000003100 4.Provan D, Stasi R, Newland AC, et al: International consensus report on the investigation and management of primary immune thrombocytopenia.Blood115(2):168-186, 2010. doi:10.1182/blood-2009-06-225565 5.Neunert C, Lim W, Crowther M, et al: The American Society of Hematology 2011 evidence-based practice guideline for immune thrombocytopenia.Blood117(16):4190-4207, 2011. doi:10.1182/blood-2010-08-302984 