Autoimmune hemolytic anemia during pregnancy and puerperium: an international multicenter experience

•AIHA in pregnancy/puerperium was severe, required therapy (steroids ± IVIG) in nearly all cases and blood transfusions in half of patients.•Adverse maternal-fetal outcomes occurred in ∼1 of 4 cases, with fetal complications being more frequent and severe than in healthy women. [Display omitted] Relapsing or occurring de novo autoimmune hemolytic anemia (AIHA) during pregnancy or puerperium is a poorly described condition. Here, we report 45 pregnancies in 33 women evaluated at 12 centers from 1997 to 2022. Among the 20 women diagnosed with AIHA before pregnancy, 10 had a relapse. An additional 13 patients developed de novo AIHA during gestation/puerperium (2 patients had AIHA relapse during a second pregnancy). Among 24 hemolytic events, anemia was uniformly severe (median Hb, 6.4 g/dL; range, 3.1-8.7) and required treatment in all cases (96% steroids ± intravenous immunoglobulin, IVIG, 58% transfusions). Response was achieved in all patients and was complete in 65% of the cases. Antithrombotic prophylaxis was administered to 8 patients (33%). After delivery, rituximab was administered to 4 patients, and cyclosporine was added to 1 patient. The rate of maternal complications, including premature rupture of membranes, placental detachment, and preeclampsia, was 15%. Early miscarriages occurred in 13% of the pregnancies. Fetal adverse events (22% of cases) included respiratory distress, fetal growth restriction, preterm birth, AIHA of the newborn, and 2 perinatal deaths. In conclusion, the occurrence of AIHA does not preclude the ability to carry out a healthy pregnancy, provided close monitoring, prompt therapy, and awareness of potential maternal and fetal complications. In this month’s CME article, Fattizzo and colleagues describe the outcomes of the rare problem of autoimmune hemolytic anemia (AIHA) during pregnancy in a multicenter cohort of 33 patients covering 45 pregnancies. The authors report good maternal outcomes despite severe hemolysis and substantial relapse rates but also reveal a higher rate of serious fetal and neonatal complications than seen in controls. These data inform practice when clinicians are faced with AIHA in a pregnant patient.