The objective of this study is to evaluate the efficacy and safety of a single intraventricular administration of Pneumostem® for treatment of Intraventricular hemorrhage (IVH) in high-risk premature infants by comparing Pneumostem-treated group with a control group.

Inclusion Criteria:

• IVH grade 3-4
• age : within postnatal day 28
• gestational age: 23-<34 weeks

Exclusion Criteria:

• Patient with severe congenital abnormalities
• Patient with antenatal brain hemorrhage
• Patient with asphyxia or Hypoxic ischemic encepalophathy
• Patient with chromosome anomalies (i.e. Edward syndrome, Patau syndrome, Down syndrome, etc) or severe congenital malformation (Hydrocephalus, Encephalocele, etc)
• Patient with a concurrent severe congenital infection (i.e. Herpes, Toxoplasmosis, Rubella, Syphilis, AIDS, etc)
• Patient withCRP > 30 mg/dL; Severe sepsis or shock
• Patient with a history of participating in other clinical studies
• Patient who is considered inappropriate to participate in the study by the investigator