Early-life painful and stressful exposures and neurodevelopment in preterm infants

Abstract

Introduction Early-life painful and stressful exposures have been associated with neurodevelopmental outcomes in preterm infants, however, findings regarding the roles of race, sex, and mother's own milk (MOM) intake in these associations are inconsistent. Method A cohort of 196 infants (28 to 32 weeks' gestation) was followed from birth to 2 years corrected age (CA) and included in the study analyses. Painful and stressful exposures during the first 28 days of life were quantified using composite pain scores derived from the Neonatal Infant Stressor Scale. Neurodevelopment was assessed using the NICU Network Neurobehavioral Scale at 36–38 weeks postmenstrual age and the Bayley-III and BITSEA at 1- and 2- years CA. Linear mixed-effects and regression models were applied. Results Higher painful exposures during the first 28 days were associated with poorer self-regulation, attention, greater stress and lethargy ( p < 0.05) at 36 to 38 weeks PMA. Among Black infants, higher composite pain scores predicted lower language, motor scores at 1- and 2- years CA and lower cognitive scores at 1 year CA ( p < 0.05). Male infants with higher composite pain scores had lower motor scores at 1 year CA compared to female infants ( p < 0.05). Greater MOM intake was linked to lower composite pain scores ( p < 0.001) but did not moderate pain–neurodevelopment association. Conclusion Black and male infants experienced higher painful exposures compared with White and female infants. Greater MOM intake showed a trend toward being protective, suggesting a potential role in individualized neonatal care.