The Newborn Intensive Care Unit Network Neurobehavioral Scale (NNNS) was used to assess healthy, full-term neonatal behavior in connection to measures of mother adversity, maternal medical risk, and baby brain sizes.

It was a prospective, longitudinal, observational cohort study of expectant mothers and their healthy, full-term children beginning in the first trimester. Two to five weeks after birth, infants had an NNNS examination and high-quality magnetic resonance imaging. A latent profile analysis of NNNS scores identified neurobehavioral characteristics in babies. Differences in maternal variables (social advantage, psychosocial stress, and medical risk) and neonatal features between profiles were evaluated using univariate and multivariate methods.

The latent profile analysis of 296 babies’ NNNS summary scores yielded three profiles: controlled (46.6%), hypotonic (16.6%), and fussy (36.8%). Male infants were more likely to have a hypotonic profile (X2=8.601; P=.014). Fussy newborns exhibited lower head circumferences (F=3.871; P=.022), as well as the smaller total brain (F= 3.522; P=.031) and cerebral white matter (F=3.986; P=.020) volumes than hypotonic infants. There were no variations in prenatal mother health, socioeconomic advantage, or psychosocial stress between profiles.

In healthy, full-term newborns with hypotonic and fussy neurobehavioral traits associated with neonatal brain volumes and head size, but not prenatal exposure to socioeconomic or psychosocial hardship, three unique neurobehavioral profiles were discovered. Following up after the neonatal period will assess if the profiles observed at birth are linked to later clinical or developmental outcomes.