Cumulative pain-related stress and developmental outcomes among low-risk preterm infants at one year corrected age

Background Extensive exposure of preterm infants to pain-related stress (PRS) at a time of physiological immaturity and rapid brain development may contribute to altered neurodevelopment. Objective To examine the relationship between early PRS and neurodevelopmental outcomes among low-risk very preterm infants at the age of one year corrected age (CA). Methods Participants included 107 infants born < 32 weeks gestational age (GA) and monitored prospectively at 12.5 months CA. Excluded were infants with severe neonatal morbidities associated with impaired neurodevelopment. PRS documentation was performed via the number of skin-breaking procedures (SBP) and by the use of the neonatal infant stressor scale (NISS). Adjustment was made for early neonatal morbidities. Results Developmental outcomes among the study infants were within the norm (mean 100 ± 11.03). Infants who underwent invasive mechanical ventilation (IMV) (n = 31) were exposed to significantly more PRS than non-IMV infants (n = 76) (p < 0.000). Developmental outcomes were similar in both groups (99.7 ± 11.1 vs. 100.8 ± 11 p = 0.63). Among IMV infants, increased exposure to PRS was associated with lower developmental scores independent of GA, gender or other sociodemographic factors. Conclusion Increased exposure to PRS among low-risk preterm infants who underwent IMV is associated with lower developmental scores at 12.5 month CA.