Born small for gestational age: consequences for growth

Area of Science:

• Pediatrics
• Human Growth and Development
• Public Health

Background:

• Strong correlation exists between birth size and adult height.
• Variations in catch-up growth incidence and final height are reported across studies and countries.
• Methodological issues may contribute to observed variations in growth outcomes.

Purpose of the Study:

• To investigate the definition of small for gestational age (SGA) and its impact on postnatal growth.
• To explore the influence of socio-economic status on early life growth faltering.
• To analyze catch-up growth patterns after disturbed fetal growth.

Main Methods:

• Analysis of two longitudinal, population-based studies from Sweden and Hong Kong.
• Inclusion of birth length data and socio-economic status indicators.
• Application of Swedish reference values for defining small for gestational age (SGA).

Main Results:

• A significant proportion of infants were classified as small for gestational age (SGA) in both populations (3.8% in Sweden, 11.9% in Hong Kong).
• The difference in birth length between extreme groups persisted until maturity.
• Catch-up growth rates were highly dependent on the SGA definition and early growth patterns.

Conclusions:

• Birth size is a critical determinant of postnatal growth and final height.
• The definition of small for gestational age (SGA) significantly affects the assessment of catch-up growth.
• Socio-economic status and early life growth faltering are important factors influencing growth trajectories.