Determinants of infant behavior and growth in breastfed late preterm and early term infants: a secondary data analysis.

BACKGROUND: Late preterm and early term infants are at increased risk of poor growth, behavioral problems, and developmental delays. This study aimed to investigate the impact of maternal and infant characteristics, feeding practices, and breastmilk composition on infant behavior following late preterm and early term delivery, and to evaluate the association between infant behavior and growth.

METHODS: Data from 52 Chinese mothers and their late preterm/early term infants participating in the Breastfeed a Better Youngster study were used. Maternal and infant characteristics were collected using questionnaires at 1 week postpartum. Breastmilk macronutrient content was measured using a human milk analyzer, and infant behavior was assessed using a 3-day infant behavior diary at 8 weeks postpartum. Feeding practices were collected at both time points using questionnaires. Multivariate models were used to assess associations between potential predictors and infant behavior and between infant behavior and growth.

RESULTS: Exclusive breastfeeding was associated with greater sleep duration (P = 0.02) and shorter crying duration (P = 0.01). Mothers with a vocational education reported greater distress duration (P = 0.006). Greater colic duration was associated with higher maternal annual income (P = 0.004). There was no significant association between infant behavior and growth (all P > 0.05).

CONCLUSIONS: Exclusive breastfeeding might promote more favorable infant behaviors in late preterm/early term infants, while the development of infant distress behaviors was associated with some maternal characteristics (maternal education and annual income). However, due to the limitations of diary methods, determinants of infant behavior should ideally be assessed using more objective measures in larger samples.