Neonatal pyknocytosis in a preterm dizygotic twin

Figure 1 Twin 1 haematocrit, haemoglobin and bilirubin levels during the first month of life. Ht: Haematocrit; Hb: Haemoglobin; Bil: Bilirubin level; Pt: Phototherapy; PRBCs: Packed red blood cell transfusion.

Figure 2 Twin 1 peripheral blood smear during the haemolytic phase of infantile pyknocytosis (magnetogastrogram x 400). Erythrocyte morphological changes: bite cells, irregularly contracted cells (pyknocytes). Changes are comparable to glucose-6-phosphate dehydrogenase deficiency.