Management of pregnancies complicated by anti-E alloimmunization

There is limited information published about anti-E alloimmunization. We review our experience at The Ohio State University to determine appropriate management strategies.

We reviewed records from June 1959 to April 2004 to identify pregnancies managed for anti-E alloimmunization. Information collected included antibody titers, DeltaOD450 values, Liley zones, middle cerebral artery peak systolic velocity, fetal and neonatal hemoglobin (Hb) and antigen typing, fetal and neonatal direct antiglobulin test, and outcomes. Pregnancies affected only by anti-E alloimmunization with a positive direct antiglobulin test or positive E antigen typing in the fetus or newborn were included.

A total of 283 pregnancies were identified with anti-E. Of these, 32 pregnancies in 27 women were at risk for hemolytic disease of the fetus or newborn from anti-E only and had complete records. Sixteen of these pregnancies had titers greater than or equal to 1:32, with amniocenteses performed for DeltaOD450 in 15 pregnancies. Values of DeltaOD450 in zone IIB or zone III in combination with serologic titers identified all pregnancies with fetal or neonatal anemia. Five of 32 (15%) fetuses had Hb less than 10 g/dL and 1 fetus had hydrops fetalis due to anti-E alloimmunization. There was 1 perinatal death attributable to anti-E hemolytic disease of the fetus or newborn. Middle cerebral artery peak systolic velocity was measured in 2 cases and corroborated information obtained from amniocentesis.

Anti-E alloimmunization can cause hemolytic disease of the fetus or newborn requiring prenatal intervention. Based on our population, clinical strategies developed for Rh D alloimmunization using maternal serology, amniotic fluid spectrophotometry, and fetal blood sampling are useful in monitoring E alloimmunization.