Outcomes: The investigators hypothesize that infants from the current TRAKC trial who were assigned to either KC group (alone or in combination with sucrose) when compared to those infants in the sucrose alone group will have: Primary outcome: H1. higher scores on the BSID-III at 18 months corrected postnatal age. Secondary outcomes: H2. higher scores in socio-affective development (Social-Emotional axis of the BSID-III and the Brief Infant Toddler Social Emotional Assessment (BITSEA); H3. lower scores on Negative Affectivity, higher scores on Surgency/Extraversion and Effortful Control as measured by the Early Childhood Behavior Questionnaire (ECBQ); H4. lower pain scores measured using the Modified Behavioral Pain Scale (MBPS) at 2, 6, 12, and 18 month;. H5. higher maternal infant interaction scores measured using Measure of Adult and Infant Soothing and Distress Scale (MAISD) at 2, 6, 12 and 18 months.