Associations between growth and childhood body composition in very preterm, late preterm and term children

Area of Science:

• Pediatric growth and development
• Body composition analysis
• Neonatal research

Background:

• Gestational age at birth is a critical factor influencing infant development.
• Understanding postnatal growth patterns is essential for assessing long-term health outcomes.
• Body composition differences in childhood can have implications for future health.

Purpose of the Study:

• To investigate the relationship between gestational age at birth and childhood body composition.
• To examine how postnatal growth trajectories influence body composition in children.
• To compare body composition between very preterm, late preterm, and term-born children.

Main Methods:

• Longitudinal study of New Zealand children born at different gestational ages (very preterm, late preterm, term).
• Measurement of body composition (fat mass index, fat-free mass index) using bioelectrical impedance at ages 2 and 6 years.
• Calculation of conditional growth rates (birth-2 years, 2-6 years) and analysis using multivariable linear regression.

Main Results:

• Children born very preterm exhibited lower weight, height, fat mass index, and fat-free mass index at 2 and 6 years compared to term-born children.
• No significant differences in body composition were observed between late preterm and term-born children.
• Weight growth between 2 and 6 years showed a stronger association with 6-year body composition (both fat mass and fat-free mass) than earlier growth or height growth.

Conclusions:

• Infants born very preterm have distinct body composition at ages 2 and 6 years compared to term-born infants.
• Late preterm birth does not appear to significantly alter childhood body composition compared to term birth.
• Postnatal weight gain during later childhood (2-6 years) is a more critical determinant of body composition than earlier growth phases.