Early psychomotor development of low-risk preterm infants: Influence of gestational age and gender.

BACKGROUND: The influence of gestational age and gender in the neurodevelopment of infants during the first year of age is not yet fully elucidated. AIMS: The purpose of this study was to identify the early occurrence of neurodevelopmental differences, between very preterm, late preterm and term born infants and the possible influence of the gender on the neurodevelopment in early infancy. METHODS: A total of 188 low-risk infants, 69 very preterms, 71 late-preterms, and 48 term infants were assessed at 3, 6, 9, 12 months corrected age using the Hammersmith Infant Neurological Examination (HINE). At two years of age infants performed the Mental Developmental Index (MDI) of the Bayley Scales of Infant Development. RESULTS: The main results indicate that both very preterms and late-preterms showed significant lower global scores than term born infants at each evaluation (p < 0.001) at HINE and namely, at 3 months for the subsections "cranial nerve" and "posture" and at every age for "tone"; no gender differences has been evidenced in neurological performances. At the MDI, very preterms showed significant lower scores (p < 0.01) than both late-preterm and term born infants; gender differences were observed for preterms only (very and late), with best performances for females. CONCLUSIONS: Our results point out the presence of gestational age and gender-dependent differences in the development of infants assessed during the first 2 years of life.