Unusual clinical features of neonatal anemia due to fetomaternal transfusion.

Fetomaternal transfusion occurs in about 50 percent pregnancies. However, it can cause severe neonatal anemia at birth. A one-day-old baby girl, small for gestational age, was born to a G1P1 woman without perinatal blood loss or obstetric complication. Pallor and mild tachypnea were noted after birth. Laboratory examination revealed severe anemia, (Hb: 4.8 gm/dl, Hct: 14.7%), reticulocytosis and normoblastemia. Direct coombs' test was negative. Brain echo examination was normal. Maternal peripheral blood smear stained with Kleihauer-Betke technique demonstrated presence of fetal cells. Following packed red blood cells transfusion, the baby's symptoms improved. The unusual clinical features were described and discussed. Kleihauer-Betke test should be performed in unexpected neonatal anemia after birth.