Abstract
Objective This study aimed to (1) define the prevalence of motor, cognitive, and language delays
in preterm infants born <32 weeks estimated gestational age (EGA); and (2) identify
the relationship between the timing of discharge from the neonatal intensive care
unit (NICU) and neurodevelopmental outcome in early childhood.
Study Design This retrospective study of 172 preterm infants born <32 weeks EGA and hospitalized
in a level-IV NICU captured medical factors, including timing of discharge, from the
NICU stay. Standardized developmental testing at 1 to 2 years corrected age was conducted
in the newborn follow-up clinic.
Results At 1 to 2 years corrected age, the sample had an average Bayley Scales of Infant
and Toddler Development (Bayley-III) cognitive composite score of 91.5 ± 17.4, language
composite score of 84.5 ± 17.3, and motor composite score of 88.9 ± 18.4. Lower EGA
at birth, necrotizing enterocolitis, patent ductus arteriosus, and oxygen requirement
for >28 days were independently associated with higher postmenstrual age (PMA) at
NICU discharge. Higher PMA at discharge was associated with poorer cognitive outcome
[p < 0.001, β = −1.1 (−1.6, −0.7)], poorer language outcome [p = 0.049, β = −0.5 (−0.9, −0.003)], and poorer motor outcome [p <0.001, β = −1.0 (−1.5, −0.5)]. For every additional week of hospitalization, scores
were an average of 1.1 points lower in cognitive, 1.0 point lower in motor, and 0.5
points lower in language domains of the Bayley-III assessment.
Conclusion Poorer cognitive, language, and motor outcomes were associated with longer hospitalization,
even after controlling for medical risk factors known to be associated with poorer
outcome. This provides further evidence for the potential role of the environment
in impacting developmental outcomes of infants hospitalized in the NICU.
Key Points
-
There are high rates of developmental impairment among preterm infants born <32 weeks
at 1 year to 2 years.
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The longer the infant is exposed to the NICU environment, the higher the risk of neurodevelopmental
challenges.
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These findings provide increased motivation for optimizing the early NICU environment.
Keywords
hospitalization - neonatal intensive care unit - length of stay - postmenstrual age
- outcomes - child development - risk factors - environment
