The prevalence of rapid weight gain in infancy differs by the growth reference and age interval used for evaluation

Area of Science:

• Pediatrics
• Public Health
• Growth Monitoring

Background:

• Infant rapid weight gain (RWG) is a potential predictor of later childhood obesity.
• Current assessments of RWG lack standardization, utilizing inconsistent growth references and age intervals.
• This variability complicates comparisons across studies and hinders accurate risk assessment.

Purpose of the Study:

• To evaluate how different growth references (2006 WHO standards vs. 2000 CDC references) and age intervals affect the prevalence of infant RWG.
• To determine the optimal criteria for assessing RWG to predict future obesity risk.

Main Methods:

• Utilized pooled data from 161 singleton term infants from two observational studies.
• Assessed RWG as an increase of >0.67 in weight-for-age z-score.
• Compared RWG prevalence across different growth references and age intervals (0-3, 0-6, 6-12, and 0-12 months) using statistical tests.

Main Results:

• The CDC references identified a higher RWG prevalence in the 0-3 month interval compared to WHO standards.
• This pattern reversed for the 6-12 and 0-12 month intervals, with WHO standards showing different results.
• RWG prevalence varied significantly across age intervals within the CDC references but not within the WHO standards.

Conclusions:

• Findings highlight the critical impact of chosen growth references and age intervals on RWG prevalence.
• Recommends using the 2006 WHO growth standards for consistent and reliable assessment of infant RWG.
• Emphasizes the need for standardized criteria in future research to enable accurate comparisons and predictions of childhood obesity.