The impact of cumulative pain/stress on neurobehavioral development of preterm infants in the NICU

Background: Vulnerable preterm infants experience repeated and prolonged pain/stress stimulation during a critical period in their development while in the neonatal intensive care unit (NICU). The contribution of cumulative pain/stressors to altered neurodevelopment remains unclear. The study purpose was to investigate the impact of early life painful/stressful experiences on neurobehavioral outcomes of preterm infants in the NICU. Methods: A prospective exploratory study was conducted with fifty preterm infants (28 0/7-32 6/7 weeks gestational age) recruited at birth and followed for four weeks. Cumulative pain/stressors (NICU Infant Stressor Scale) were measured daily and neurodevelopmental outcomes (NICU Network Neurobehavioral Scale) were examined at 36-37 weeks post-menstrual age. Data analyses were conducted on the distribution of pain/stressors experienced over time and the linkages among pain/stressors and neurobehavioral outcomes. Results: Preterm infants experienced a high degree of pain/stressors in the NICU, both in numbers of daily acute events (22.97 +/- 2.30 procedures) and cumulative times of chronic/stressful exposure (42.59 +/- 15.02 h). Both acute and chronic pain/stress experienced during early life significantly contributed to the neurobehavioral outcomes, particularly in stress/abstinence (p < 0.05) and habituation responses (p < 0.01), meanwhile, direct breastfeeding and skin-to-skin holding were also significantly associated with habituation (p < 0.01-0.05). onclusion: Understanding mechanisms by which early life experience alters neurodevelopment will assist clinicians in developing targeted neuroprotective strategies and individualized interventions to improve infant developmental outcomes. (C) 2017 Elsevier B.V. All rights reserved.