This is single center study. The investigators will try to know that relationships between intestinal microbiome and mortality in preterm infants and what relationships is between intestinal microbiome in preterm infants and morbidity, mortality.

Microbiome is the collection of all the microorganisms living in association with the human body which are consist of eukaryotes, archaea, bacteria and viruses. Microbiome in an average human body number are ten times more than human cells and have about 1000 more genes than are present in the human genome. There are symbiotic relationships between human and microbiome. If investigators are able to know about relationships between newborn and intestinal microbiome, mortality and morbidity in preterm infants may be improved. The investigators will collect the first and weekly stool of participants and analyze DNA of microbiome thorough Metagenomic anlysis. The results between 3 groups(preterm, late preterm and full-term infants) will be compared. The investigators expect that a mean distribution of intestinal microbiome in newborns(preterm, late preterm and full-term) is defined and that relationships between mortality, morbidity and intestinal microbiome.

Inclusion Criteria:

• preterm infants who were born at gestational age of less than 36 weeks from approval date to Feb 28th 2019
• full-term infants who were born at gestational age of greater than 37 weeks from approval date to Feb 28th 2019

Exclusion Criteria:

• newborns with congenital anomaly
• newborns with genetic syndrome
• newborns without consent of parents

newborn infants who were born and admitted on neonatal intensive care unit of Wonju Severance Christian Hospital

Yes: There is a plan to make IPD and related data dictionaries available.

starting from august 2017 until February 2019

neonatology pediatrics infections