RESUMO
INTRODUCTION: Low birth weight (LBW), biological vulnerability that includes preterm birth (PTB) and small for gestational age (SGA), is associated with reduced maternal sensitivity ("making accurate inferences about an infant's physical and emotional needs and responding appropriately") and impaired infant cognitive development. However, research does not examine if preterm birth, SGA, or both drive these associations. This study separated these measures of biological vulnerability to examine associations of LBW, PTB, and SGA with maternal sensitivity and infant cognitive development (controlling for maternal depression, breastfeeding, and demographic covariates). METHODS: The sample included 6900 9-month-old infants from the Early Childhood Longitudinal Study-Birth Cohort and used birth certificate data, maternal interviews, assessments of maternal sensitivity and infant cognitive development. Multiple linear regressions examined LBW, PTB, and SGA associations with concurrent measures of maternal sensitivity and infant cognition. RESULTS: Of the biological vulnerabilities, preterm birth had the strongest negative association with maternal sensitivity (F1,6450 = 29.48 versus 15.33 and 5.51, ps < .001) and infant cognitive development (F1,6450) = 390.65 versus 248.02 and 14.43, ps < .001). In the final regression model, preterm birth and maternal sensitivity were uniquely associated with infant cognitive development (R2 = .05, p < .001), after controlling for maternal depression, breastfeeding, and demographics. CONCLUSION: In this nationally representative infant sample infants, PTB had a stronger negative association with both maternal sensitivity and infant cognitive development in comparison to SGA or LBW. The LBW designation combines infants born preterm with SGA infants, potentially minimizing differences in developmental outcomes of PTB and SGA infants.
