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 <32weeks gestational age (GA) and monitored prospectively at 12.5months 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 12.5month CA.