Predictors of Resilience Among Infants at Risk for Rapid Weight Gain

The study objective was to investigate factors associated with resilience to rapid weight gain (RWG) among predominantly bottle-fed infants.

Data came from 1,353 mothers who participated in the Infant Feeding Practices Study 2. Mothers completed a prenatal questionnaire and monthly surveys of infant feeding and growth between birth and 12 months. Infants were classified as resilient if they were predominantly bottle fed but did not exhibit RWG between birth and the latter half of infancy (≥ +0.67 change in weight-for-age z score).

Thirty-five percent of the sample (n = 467) was predominantly bottle fed but did not exhibit RWG ("Resilient"), 17% (n = 228) was predominantly bottle fed and exhibited RWG ("Not Resilient"), and 49% (n = 658) was not predominantly bottle fed ("Low Risk"). Significant predictors of resilience to RWG were greater gestational age (P = 0.042) and weight (P < 0.001) at birth, lower frequency of adding cereal to the bottle (P = 0.022), lower frequency of infant-led bottle-emptying (P = 0.047), and greater frequency of maternal encouragement of bottle-emptying (P = 0.002).

Associations between bottle-feeding and RWG may be moderated by infant characteristics and maternal feeding practices. The present study highlighted several characteristics of predominantly bottle-fed infants who were resilient to RWG, but further research is needed to identify a broader array of key targets for future intervention efforts.