Recent evidence suggests newborn infants are more sensitive to pain and stress than older children and adults. The level of sensitivity may be especially acute for newborns who are at-risk for developmental problems due to prenatal exposure to pain, antidepressants or illicit drugs. Studies suggest that early exposure to pain and stress leads to changes in the newborn’s brain circuitry, and may increase vulnerability to abnormal behaviour and development. This has led to a search for better ways to understand and recognize infant pain and measure the effects of pain treatment. Dr. Fay Warnock is investigating the actions and interactions of healthy and at-risk infants. The research involves confirming a comprehensive list of behaviour associated with newborn distress, and comparing the actions of healthy and at-risk newborns during and after routine diaper change and heel lancing, a common procedure for obtaining a blood sample to screen infants for metabolic errors. She is also linking newborn behaviour with changes in facial action and heart rate. The research will further develop measures of newborn pain, improve understanding of how caregivers can help alleviate pain, and lead to protocols for preventing, assessing and treating newborn pain.