The downstream consequences of premature birth may also mediate the association between preterm birth and ASD, including intracranial hemorrhage, bronchopulmonary dysplasia, cerebral dysfunction, high SNAP-II score, health status requiring high-frequency ventilation, acid suppressant use, and neonatal infections and inflammation (IL-6, NT-4, serum amyloid A, TNF-α, IL-4, and fetal histological chorioamnionitis). This evidence concerns the gene IL6 and bronchopulmonary dysplasia.