Association of Birth Weight Centiles with Infant and Child Growth Dynamics

ABSTRACT Importance Infants born small or large for gestational age exhibit different growth patterns compared with appropriate-for-gestational age counterparts. Evidence is lacking on how birth weight centiles beyond conventional thresholds predict early life growth. Objective Quantify association of birth weight centile range with infant and child growth. Design Prospective cohort study. Setting France, Netherlands, Portugal, Singapore, United Kingdom, United States. Participants Singletons from seven birth cohort studies with repeated growth measurements from age one week to 10 years. Five European cohorts were used for discovery analysis, and remaining cohorts for replication. Exposures Birth weight centiles standardised for sex and gestational age using the INTERGROWTH-21 st standards and classified into deciles. Main Outcomes and Measures Infant height ( cm/month ) and weight ( g/month ) velocity at 1, 6, 12, 24 months, body mass index (BMI: kg/m 2 ) and age ( months or years ) at infancy BMI peak and childhood BMI rebound, and overweight/obesity at age 10 years. Results The discovery analysis included 36,018 children (48% girls, birth years: 1991-2011). Growth velocity, peak BMI (mean: 17.7 vs. 17.3 kg/m 2 ), age at peak BMI (10.2 vs. 10.4 months ), rebound BMI (15.6 vs. 15.5 kg/m 2 ), age at rebound BMI (5.3 vs. 5.0 years ), and overweight/obesity prevalence were broadly similar in boys and girls. Compared with lowest birth weight decile (