The objectives of our study were to evaluate the relationship between Hb level at birth and primary outcomes of IVH, NEC, broncho-pulmonary dysplasia (BPD), retinopathy of prematurity (ROP), and death before discharge as well as secondary outcomes of receiving red blood cell transfusions, length of intensive care stay, and total neonatal unit days in preterm infants born at ≤32 weeks gestation. The gene discussed is GSTM1; the disease is retinopathy of prematurity.