Abstract
Background: Previous studies show inconsistent relations between child care and obesity, but few assessed longitudinal associations during infancy and even fewer included racially diverse children. We examined associations of time infants spent in child care, both overall and in different types of care, with weight status at 6 and 12 months. Methods: We examined 664 infants living in central North Carolina. We conducted adjusted multivariable linear regressions examining (1) child care from birth to 6 months and 6-month weight-for-length (WFL) z-score, and (2) child care from birth to 12 months and 12-month WFL z-score. We assessed any child care and child care by type, including relative care, informal care by a nonrelative, formal child care, and a combination of care (e.g., relative and informal care). Results: Nearly 70% of infants were black and 49% were female. After adjustment for potential confounders, any child care was not associated with WFL z-score at 6 months (0.07; 95% confidence intervals [CI] -0.02 to 0.16; p = 0.13) or 12 months (0.05; 95% CI -0.02 to 0.12; p = 0.19). However, greater combination care was associated with higher WFL z-score at 6 months (0.68; 95% CI 0.23-1.13; p = 0.003) and greater care by a relative was associated with higher WFL z-score at 12 months (0.16; 95% CI 0.05-0.26; p = 0.005). Conclusions: Although we did not observe associations with any child care, combination care and relative care during infancy were associated with higher weight. Interventions aimed at preventing excessive weight gain in early life may target relatives who provide regular care for infants.