This study collected cases of early anemia (peripheral blood Hb ≤ 145 g/L and HCT ≤ 0.43 within the first week after birth) according to domestic standards combined with clinical practice, exploring the risk factors for early neonatal anemia and investigating the relationship between early neonatal anemia and myocardial biomarkers. This evidence concerns the gene GSTM1 and anemia (phenotype).