Early-life factors associated with neurobehavioral outcomes in preterm infants during NICU hospitalization

Pediatr Res. 2022 Dec;92(6):1695-1704. doi: 10.1038/s41390-022-02021-y. Epub 2022 Mar 25.

Abstract

Background: The aim of this study was to investigate the influence of early-life pain/stress and medical characteristics on neurobehavioral outcomes in preterm infants.

Methods: A prospective cohort study was conducted with 92 preterm infants (28-32 weeks gestational age [GA]). Early-life pain/stress was measured via the Neonatal Infant Stressor Scale (NISS) during the first 28 days of NICU hospitalization. Neurobehavioral outcomes were evaluated using the NICU Network Neurobehavioral Scale at 36-38 weeks post-menstrual age. Functional regression and machine learning models were performed to investigate the predictors of neurobehavioral outcomes.

Results: Infants experienced daily acute pain/stress (24.99 ± 7.13 frequencies) and chronic events (41.13 ± 17.81 h). Up to 12 days after birth, both higher acute and chronic NISS scores were associated with higher stress scores; and higher chronic NISS scores were also related to lower self-regulation and quality of movement. Younger GA predicted worse neurobehavioral outcomes; GA < 31.57 weeks predicted worse stress/abstinence, self-regulation, and excitability; GA < 30.57 weeks predicted poor quality of movement. A higher proportion of maternal breastmilk intake predicted better self-regulation, excitability, and quality of movement in older GA infants.

Conclusions: Preterm infants are vulnerable to the impact of early-life pain/stress. Neurobehavioral outcomes are positively associated with increased GA and higher maternal breastmilk intake.

Impact: During the first 12 days of life, preterm infant neurobehavioral outcomes were vulnerable to the negative impact of acute and chronic pain/stress. Future research is warranted to investigate the long-term effects of early-life pain/stress on neurobehavioral outcomes. Gestational age remains one of the critical factors to predict neurobehavioral outcomes in preterm infants; older gestational age significantly predicted better neurobehavioral outcomes. Feeding with a higher proportion of maternal breastmilk predicted better neurobehavioral outcomes. Future research is warranted to investigate how maternal breastmilk may buffer the negative effects of early-life pain/stress on neurobehavioral outcomes.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Hospitalization
  • Humans
  • Infant
  • Infant, Newborn
  • Infant, Premature* / physiology
  • Intensive Care Units, Neonatal*
  • Pain
  • Prospective Studies