Greater analgesic effects of sucrose in the neonate predict greater weight gain to age 18 months

Intraoral sucrose has analgesic effects in the newborn period. The hedonic and analgesic effects of sucrose overlap and hedonic response to sweet food is associated with adiposity. The potential association between the analgesic effects of intraoral sucrose in the newborn period and subsequent weight gain has not been examined. Healthy, term newborns received 25% intraoral sucrose or water prior to metabolic screen heel stick. Negative affect, quiet alert behavior, and sleepiness were coded during heel stick. Weight and length were measured and z-score (WLZ) calculated at birth, 9, and 18 months. Mixed models tested associations of behavioral response to heel stick with WLZ trajectory among infants receiving sucrose (n = 154) versus water (n = 117). Among infants receiving sucrose prior to heel stick with birth WLZ = the median, less negative affect and more sleepiness during heel stick were each associated with greater increases in WLZ. These associations were not present among infants receiving water only prior to heel stick. Greater analgesic effects of sucrose in the neonate were associated with greater future increases in WLZ, especially among infants with higher birth WLZ. Greater opioid-mediated newborn behavioral response to intraoral sucrose may be a marker for future obesity risk.