The Recurrence Risk of Fetomaternal Hemorrhage.

Massive fetomaternal hemorrhage (FMH) can cause devastating pregnancy outcomes. Perinatal prognosis may be improved by intrauterine transfusion, but the appropriate management for these pregnancies remains unclear. To determine the recurrence risk of FMH after intrauterine transfusion, we performed a systematic review of all case reports/series of patients with proven FMH treated with intrauterine transfusion and who had subsequent follow-up of at least 72 h until delivery. This revealed 13 cases, with 1 additional case from our institution. Ten patients (71.4%) had a second episode of FMH requiring a second intrauterine transfusion. Five patients (35.7%) required at least 3 intrauterine transfusions. The time interval between intrauterine transfusions was progressively reduced. The gestational age at the onset of signs/symptoms was 26.6 ± 2.1 weeks, and gestational age at delivery was 34.2 ± 4.2 weeks. Two cases of fetal demise (14.3%) and no neonatal deaths were recorded. Limited postnatal follow-up on 8 neonates was normal. The mean neonatal hemoglobin and transfusion rates were 13.2 ± 5.7 g/dL and 33.3%, respectively. Close fetal monitoring, likely daily, is necessary to recognize FMH recurrence. Several transfusions may be necessary once FMH is diagnosed if pregnancy is allowed to continue > 72 h.