Establish a clinical diagnosis and treatment and long-term follow-up database of preterm infants, and analyze the effects of prenatal factors (including genetic characteristics, maternal diseases, etc.), postnatal diagnosis and treatment measures and family maintenance environment after discharge on preterm infant mortality and major diseases in the near and long term.

As an increasing large group, the long-term quality of life and health status of preterm infants have become a very important public health problem in China. This cohort study is a single center clinical cohort study. By collecting the clinical diagnosis, treatment and follow-up data of preterm infants admitted to the neonatal department of our hospital for 3 consecutive years (about 1200 cases), and following them for 18 years, a relatively complete resource database for the long-term health and development of preterm infants is established. The effects of perinatal factors, diagnosis and treatment methods and family rearing environment on the survival rate, neurointelligence development, chronic metabolic diseases and respiratory diseases of preterm infants were analyzed. It provides a basis for further improving the diagnosis and treatment plan, exploring potential therapeutic targets and establishing prediction models.

Inclusion Criteria:

1. Live born newborns with gestational age ≤ 36 + 6 weeks
2. Transfer to the neonatal ward of Shanghai Children's medical center within 24 hours after birth
3. Those who have lived in Shanghai for more than 1 year and plan to live in Shanghai for a long time. Parents voluntarily participated in the study and signed informed consent

Exclusion Criteria:

1. Premature infants: termination of treatment due to family factors (non-disease reasons) and hospitalization time ≤ 2 weeks
2. Major congenital malformations
3. Parents refuse to participate in the study

premature infants with gestational age ≤ 36 + 6 weeks.