GSTM1 and anemia (phenotype): Most of the neonates on respiratory support received PRBCTs in a manner consistent with the CBS, BCSH, and ANBA guidelines, whereas most of the neonates not on oxygen (O2) therapy received PRBCTs for late anemia (at three weeks or more of age) at a higher Hb level than that suggested by the CBS and BCSH guidelines but consistent with the ANBA guidelines.