Alterations in brain structure and neurodevelopmental outcome in preterm infants hospitalized in different neonatal intensive care unit environments

Abstract

Objective: To evaluate associations between neonatal intensive care unit (NICU) room type (open ward and private room) and medical outcomes; neurobehavior, electrophysiology, and brain structure at hospital discharge; and developmental outcomes at 2 years of age.

Study design: In this prospective longitudinal cohort study, we enrolled 136 preterm infants born <30 weeks gestation from an urban, 75-bed level III NICU from 2007-2010. Upon admission, each participant was assigned to a bedspace in an open ward or private room within the same hospital, based on space and staffing availability, where they remained for the duration of hospitalization. The primary outcome was developmental performance at 2 years of age (n = 86 infants returned for testing, which was 83% of survivors) measured using the Bayley Scales of Infant and Toddler Development, 3rd Edition. Secondary outcomes were: (1) medical factors throughout the hospitalization; (2) neurobehavior; and (3) cerebral injury and maturation (determined by magnetic resonance imaging and electroencephalography).

Results: At term equivalent age, infants in private rooms were characterized by a diminution of normal hemispheric asymmetry and a trend toward having lower amplitude integrated electroencephalography cerebral maturation scores (P = .02; β = -0.52 [CI -0.95, -0.10]). At age 2 years, infants from private rooms had lower language scores (P = .006; β = -8.3 [CI -14.2, -2.4]) and a trend toward lower motor scores (P = .02; β = -6.3 [CI -11.7, -0.99]), which persisted after adjustment for potential confounders.

Conclusion: These findings raise concerns that highlight the need for further research into the potential adverse effects of different amounts of sensory exposure in the NICU environment.

Keywords: Amplitude integrated electroencephalography; Bayley Scales of Infant and Toddler Development, 3rd edition; Bayley-III; CRIB; Critical Risk Index for Babies; Echo time; FA; FAD; Fractional anisotropy; Functional connectivity magnetic resonance imaging; ITSEA; Infant Toddler Social Emotional Assessment; M-CHAT; MRI; Magnetic resonance imaging; McMaster Family Assessment Device; Modified Checklist for Autism in Toddlers; NICU; NICU Network Neurobehavioral Scale; NNNS; Neonatal intensive care unit; PDA; PMA; Patent ductus arteriosus; Postmenstrual age; Repetition time; TE; TR; aEEG; fcMRI.

Figure 1

Patient flow diagram.

Figure 2

Hemispheric sulcal depth asymmetry (left-right) t-statistic maps for term control (n=12); private room (n=23), and open ward infants (n=20). The superior temporal sulcus asymmetry for the term controls was significant based on the 3D trajectory of the sulcal fundus (illustrated by non-outlined color, as reproduced with permission from Journal of Neuroscience). Note the differences in left-right asymmetry of the superior temporal sulcus (arrows) across groups, with greater hemispheric asymmetry present in the open ward (1647 mm²) compared with the private room infants (1281 mm²). T-maps are scaled to a t-value of ±3.0, which corresponds to p=0.0121 for the term controls; p=0.0074 for the open ward; and p=0.0066 for the private room infants.