The Preterm Birth Cohort Study in Guangzhou (PBCSG) aims to explore the impact of genetic and environmental factors including life styles on preterm birth, to examine the interaction effect between these factors, and to follow up the short-term and long-term outcomes of preterm childrens.

Preterm birth has become the leading cause of neonatal death and the second leading cause of death among children under five years of age. Preterm childrens are more susceptible to adverse health problems including brain injury and neurodevelopment delay, and are at risk of chronic diseases which could impair the health status and life quality later in life. However, the causes of preterm birth is still not clear, and there are no effective prediction and preventive strategies. The Preterm Birth Cohort Study in Guangzhou (PBCSG) will collect the epidemiological,clinical information and biological specimens including maternal blood,cord blood, placenta, children's blood and stool samples of preterm childrens and their mothers. More importantly, childrens' health status, physical and neurodevelopment will be followed up to late childhood and adolescence. The preterm birth cohort would help to explore the mechanism of preterm birth and to examine the short- and long-term influence of preterm birth on physical health and neurodevelopment of childrens.

Inclusion Criteria:

1. Born before 37 weeks of gestation
2. Born in Guangzhou Women and Children's Medical Center
3. Intended to remain in Guangzhou for more than 3 years

Exclusion Criteria:

1. Multiple birth
2. Stillbirth
3. With major congenital abnormalities

The study population are childrens born before 37 weeks of gestation and their mothers in Guangzhou.