The results of this study showed that single- and multiple-course prenatal corticosteroids applied to threatened preterm delivery had little difference in the incidence of hypoxic-ischemic encephalopathy in neonates, the serum NSE concentration at birth and at 3 days of birth, the NBNA score, the incidence of RDS, and the perinatal mortality rate. This evidence concerns the gene ENO2 and newborn respiratory distress syndrome.