RESUMEN
OBJECTIVES: To examine healthy, full-term neonatal behavior using the Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS) in relation to measures of maternal adversity, maternal medical risk, and infant brain volumes. STUDY DESIGN: This was a prospective, longitudinal, observational cohort study of pregnant mothers followed from the first trimester and their healthy, full-term infants. Infants underwent an NNNS assessment and high-quality magnetic resonance imaging 2-5 weeks after birth. A latent profile analysis of NNNS scores categorized infants into neurobehavioral profiles. Univariate and multivariate analyses compared differences in maternal factors (social advantage, psychosocial stress, and medical risk) and neonatal characteristics between profiles. RESULTS: The latent profile analysis of NNNS summary scales of 296 infants generated 3 profiles: regulated (46.6%), hypotonic (16.6%), and fussy (36.8%). Infants with a hypotonic profile were more likely to be male (χ2 = 8.601; P = .014). Fussy infants had smaller head circumferences (F = 3.871; P = .022) and smaller total brain (F = 3.522; P = .031) and cerebral white matter (F = 3.986; P = .020) volumes compared with infants with a hypotonic profile. There were no differences between profiles in prenatal maternal health, social advantage, or psychosocial stress. CONCLUSIONS: Three distinct neurobehavioral profiles were identified in healthy, full-term infants with hypotonic and fussy neurobehavioral features related to neonatal brain volumes and head circumference, but not prenatal exposure to socioeconomic or psychosocial adversity. Follow-up beyond the neonatal period will determine if identified profiles at birth are associated with subsequent clinical or developmental outcomes.