Identifying Very Early Behavioral Predictors of Autism Spectrum Disorder (ASD) in NICU Infants

Background: Infants with obstetric/neonatal complications may be at higher risk for ASD. Our longitudinal studies evaluate development of attention, motor, and regulatory mechanisms from birth in NICU infants. Evaluation of records from 1995-present indicated ~1.5% of our population with ASD, with higher % after 2000 (1% vs 2%, p<.05); ~1/3 diagnosed at IBR, 2/3 by education/community resources.

Objectives: To identify useful behavioral predictors of ASD during early infancy.

Methods: NICU infants later diagnosed with ASD (n=37) were compared to non-ASD (n=2342) children on a range of behaviors from birth to 3 1/2 years.

Results: ASD children were predominantly male, with higher-educated mothers. They were born at lower gestational age and birthweight, but did not differ on intrauterine growth, Apgar Scores, or CNS involvement. In analyses controlling gender, CNS severity, and maternal education, ASD children exhibited a pattern of behavioral deficits starting in the newborn period. Their neonatal neurobehavior at 1 month (adjusted) showed higher incidences of visual asymmetry, increased hypertonicity in arms, but better head extension (p's<.01). They also had poorer arousal modulation of visual attention at 4 months (adjusted) (p<.001), showing greater stimulus seeking more similar to younger or cocaine-exposed infants. Bayley-II motor and mental scores were lower starting at 7 and 10 months, respectively. After 2 years, deficits were found, with increased incidence of middle/high arm guard during gait analyses, and with lower scores on Griffiths Mental Development Scales.

Conclusions: As early as newborns, infants later diagnosed with ASD may form a distinct sub-population within NICU-assigned babies, with atypical development of visual, motor, and regulatory processes compared to other high-risk infants. Furthermore, disintegration on standardized testing may be expected as early as 7 months, which typically only occurs in infants with the most severe CNS pathology. These differences may be indicative of precursors to ASD at older ages.