The objective of the study was to report the maternal and perinatal outcome in patients with severe red cell alloimmunization in pregnancy who were treated with immunomodulation therapy.

This was a retrospective multicenter case series. Patients with a history of early second-trimester fetal loss secondary to severe maternal red cell alloimmunization or patients with markedly elevated maternal antired cell titers felt to be consistent with poor fetal outcome were offered treatment. Therapy consisted of serial plasmapheresis followed by weekly infusions of intravenous immune globulin (IVIG). Maternal titers were measured before and after plasmapheresis.

Pregnant patients with either a history of a previous perinatal loss (n = 7) or markedly elevated maternal antibody titers (n = 2) were treated with combined plasmapheresis and IVIG. All 9 fetuses subsequently required intrauterine transfusions (median 4; range 3-8). All infants survived with a mean gestational age at delivery of 34 weeks (range 26-38 weeks). Maternal antired cell titers were significantly reduced after plasmapheresis (P < .01) and remained decreased during IVIG therapy. Serial peak middle cerebral artery velocities remained below the threshold for moderate to severe fetal anemia during therapy.

Combined immunomodulation with plasmapheresis and IVIG represents a successful approach to the treatment of severe maternal red cell alloimmunization.