Elsevier

The Journal of Pediatrics

Volume 162, Issue 3, March 2013, Pages 470-476.e1
The Journal of Pediatrics

Original Article
Patterns of Altered Neurobehavior in Preterm Infants within the Neonatal Intensive Care Unit

https://doi.org/10.1016/j.jpeds.2012.08.011Get rights and content

Objective

To investigate differences in neurobehavior between preterm infants at term and full-term infants, changes in neurobehavior between 34 weeks postmenstrual age (PMA) and term equivalent in the preterm infant, and the relationship of neurobehavior to perinatal exposures.

Study design

In this prospective cohort study, 75 infants were tested at 34 weeks PMA and again at term using the Neonatal Intensive Care Unit Network Neurobehavioral Scale. Infants underwent magnetic resonance imaging at term equivalent. Regression was used to investigate differences in the scale's domains of function across time and in relation to perinatal exposures.

Results

At term equivalent, preterm infants exhibited altered behavior compared with full-term infants, with poorer orientation (P < .001), lower tolerance of handling (P < .001), lower self-regulation (P < .001), poorer reflexes (P < .001), more stress (P < .001), hypertonicity (P < .001), hypotonia (P < .001), and more excitability (P = .007). Preterm infants from 34 weeks PMA to term equivalent, demonstrated changes in motor functions with declining quality of movement (P = .006), increasing hypertonia (P < .001), decreasing hypotonia (P = .001), and changes in behavior with increasing arousal (P < .001), increasing excitability (P < .001), and decreasing lethargy (P < .001). Cerebral injury was associated with more excitability (P = .002). However, no associations were detected between any of the perinatal exposures and developmental change from 34 weeks PMA to term equivalent.

Conclusion

Preterm infants have altered neurobehavior in a broad number of domains at term equivalent. Cerebral injury alters neurobehavior but does not appear to impair early neurobehavioral changes. Important neurobehavioral changes occur before term, and this provides an opportunity for interventions in the neonatal intensive care unit.

Section snippets

Methods

This study was a prospective cohort design recruiting inborn admissions of preterm infants born at less than 30 weeks estimated gestational age (EGA) within the first 3 days of life between 2007 and 2010. Sample size calculations were conducted before enrollment. A sample size of 84 was needed to detect a medium effect with 80% power and α = 0.05; thus, we planned to enroll 120 infants to account for attrition. We chose a medium effect, given that small differences in neurobehavior might be

Results

Of the 120 infants enrolled in the study (Table I), 16 died, 1 was transferred to another hospital, 1 was later determined to have a congenital anomaly, and 6 withdrew from the study. In addition, 21 infants did not have neurobehavioral data for both 34 weeks PMA and term equivalent, leaving 75 infants with data from both evaluations. Of the 21 infants without assessment data at both time points, 8 were too unstable to undergo assessment at 34 weeks, and 13 were discharged before term and did

Discussion

The present study defines early neurobehavioral changes using the NNNS scale in high-risk preterm infants in the NICU. Our key findings are: (1) that preterm infants demonstrate alterations across many neurobehavioral domains of function by term equivalent compared with healthy term infants; (2) that significant changes in neurobehavior occur in the last 6 weeks before term equivalent; and (3) that aside from cerebral injury, perinatal exposures were not associated with early neurobehavioral

References (28)

  • K. Mikkola et al.

    Neurodevelopmental outcome at 5 years of age of a national cohort of extremely low birth weight infants who were born in 1996-1997

    Pediatrics

    (2005)
  • J. Dubois et al.

    Mapping the early cortical folding process in the preterm newborn brain

    Cereb Cortex

    (2008)
  • A.U. Mewes et al.

    Regional brain development in serial magnetic resonance imaging of low-risk preterm infants

    Pediatrics

    (2006)
  • B.M. Lester et al.

    The Neonatal Intensive Care Unit Network Neurobehavioral Scale procedures

    Pediatrics

    (2004)
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    Supported by the National Institute of Health (R01 HD057098), the Washington University Intellectual and Developmental Disabilities Research Center (NIH/NICHD P30 HD062171), and the Doris Duke Foundation, none of which were involved in the study design, data collection, interpretation of data, writing the report, or in the decision to submit the paper for publication. The authors declare no conflicts of interest.

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