Abstract: With the rapid development of obstetrics and neonatal intensive care technology, the survival rate of preterm infants with extreme survival has increased year by year. However, due to immature development of the nervous system, those infants are easily affected by various high-risk factors, which result in the increased incidence of brain damages. The multiple brain damages will seriously threaten the growth and development of premature infants and their physical and mental health. As the bond between mother and fetus, placenta has become an important organ in the study of neurodevelopmental dysplasia in preterm infants. It has been found that the placental histopathology associated with brain injury in preterm infants is often accompanied by the changes in acute chorionic amnionitis, placental perfusion disorder, chorionic angiopathy, et al. Molecular pathology showed the increased inflammatory factors, the excessive expressions of hypoxic induction factors and the decreased placental exosome protection. The miRNAs can be changed with the intrauterine environment, reflecting the role of epigenetic regulation in protecting the fetal nervous system from external factors. The article reviews the characteristics of placenta changes in preterm infants, including the changes of histopathology, molecular pathology and epigenetics, and the potential mechanism. It is of worth to test those placenta factors in preterm infants to assess the adverse outcomes of brain injury.

Key words: Fetus, Leukomalacia, periventricular, Placenta, MicroRNAs