Sex differences in parent perceived barriers to physical activity (PPBTPA) are identified for older children, but limited studies explore such perceptions for premature infants early in life. Thus, we explored PPBTPA in a randomized control trial (RCT) entitled Project BEGIN, which studied the impact of an exercise intervention on premature infants' growth, in order to: 1) examine if PPBTPA predict premature infants’ body composition (weight for length (WFL), Lean body mass (LBM)), and 2) assess whether sex differences exist.


Secondary analysis of a prospective RCT of mother-infant dyads who completed baseline demographic and parent perceptions of physical activity questionnaires, and a DXA at 12 months. Associations between demographic characteristics, PPBTPA, WFL, and LBM at 12 months (mo) were explored using correlations in unadjusted analyses. Linear regression models were used in adjusted analyses.


(n=73) Mothers: Age (mean(SD)) 30.64(5.8) years, Hispanic 71.8%, monthly income less than $3,000 54.3%, education above high school 58.3%; Infants: 50.7% Female, gestational age (mean(SD)) 27.4(1.7) weeks, birthweight (mean(SD)) 976.7(239.0)g, 12-mo WFL (mean(SD)) 126.09(16.4), 12-mo LBM (mean(SD)) 6,544.4(695.9)g. Unadjusted analyses: PPBTPA was associated with: All, WFL (p=0.02), and LBM (p=0.04); Females, WFL (p=0.01), LBM (0.06); Males, WFL (p=0.33), LBM (p=0.37). No significant associations observed with demographic characteristics and WFL or LBM. Adjusted Analyses for birthweight: PPBTPA was associated with: All, WFL (p=0.03), and LBM (p=0.05); Females, WFL (p=0.03), LBM (p=0.10); Males, not significant.


Though the mechanism of the relationship between the sex differences identified in the association of PPBTPA and WFL remains unclear, study findings raise questions about whether parent attitudes about an infant’s sex influence behaviors that favor motor enhancing activities for males more than females, which result in actual changes in body composition.