Longitudinal cognitive assessment in healthy late preterm infants.

BACKGROUND: Longitudinal cognitive development in late preterm (LP) infants has not been previously evaluated, using structured assessments. AIM: To assess longitudinally cognitive development in a population of healthy LP infants from 12 months to preschool age. METHODS: Sixty-two low-risk LP infants (33-36 weeks gestation) with normal or only minor findings on their cranial ultrasound scans were included in the study. They were assessed at 12 and 18 months corrected age using the Bayley Scales of Infant Development II to obtain the mental development index (MDI) and then at preschool age (mean age 62 ± 7 months) using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-R). RESULTS: The MDI scores obtained at both 12 and 18 months corrected age were within the reported normative range. Using uncorrected ages, their scores were lower at both ages than those obtained using CA (p < 0.01). Full-scale IQ scores within the reported normal range were obtained at 5 years using the WPPSI-R for all but 6 children. Females had significantly higher scores than males (p < 0.001) for the MDI at both 12 and 18 months corrected and uncorrected age. No gender differences were found at preschool age using the WPPSI-R. CONCLUSIONS: Our results suggest that over 90% of the low-risk late preterms reach an MDI and IQ at preschool age within normal range.

Neurological examination of late-preterm infants at term age.

BACKGROUND: Late-preterm infants represent 70% of the whole preterm population. AIMS: To establish the range and frequency distribution of neonatal neurological scores in a large cohort of low risk late-preterm infants and the possible differences with full-term infants. METHODS: Three hundred-seventy-five healthy infants born between 34 and 36 weeks gestational age (GA) without major brain lesions were assessed between 39 and 41 weeks post-menstrual age using the Hammersmith Neonatal Neurologic Assessment and compared to the scores obtained using the same examination in full-term infants. RESULTS: Infants born at 35 and 36 weeks GA had similar median scores in 32 of the 34 items. Infants born at 34 weeks GA had a different profile of scores compared to those born at 35 and 36 weeks, mainly in the tone items. While in infants born at 34 weeks the assessment at term age showed similar median scores to those obtained in full-term infants in 25/34 items, in those born at 35 and 36 GA the number of scores similar to full-term infants increased to 29/34. The main differences involved the tone items, with more marked flexor tone in the limbs and better head control for those born at 35 and 36 weeks. CONCLUSIONS: This data can help as reference data when examining late-preterm infants at term age to see where the individual child stands compared to age matched low risk infants and to identify signs that are outside the reported range in infants with lesions or other risk factors.

Early visual assessment in preterm infants with and without brain lesions: correlation with visual and neurodevelopmental outcome at 12 months.

BACKGROUND: Several studies have reported the development of various aspects of visual function in infancy and early childhood in both preterm and term-born infants, but only a few studies have focused on the predictive power of neonatal visual findings in infants with brain lesions. AIMS: To explore visual findings at term age, and at 3 and 12 months corrected age in preterm infants (gestational age <33 weeks) with and without brain lesions; to compare the assessment at term age and at 12 months; and to assess the relationship between visual findings and neurodevelopmental outcome at 12 months. STUDY DESIGN: Cranial ultrasound scans (US) were classified in normal, mild or major abnormalities. One-hundred and forty-five infants were assessed with age specific tests for visual function at term age, and at 3 and 12 months. Neurodevelopmental assessment (Griffiths' Scales) was performed at 12 months. RESULTS: A good correlation was found between early and late visual assessment and neurodevelopment outcome. Of the 121 infants with normal neonatal visual assessment, 119 were also normal at 12 months and 116 had normal developmental quotient. Of the 24 infants with abnormal neonatal visual assessment, 12 were also abnormal at 12 months. All the false positives had normalised by 3 months. Of the 35 infants with major US abnormalities, 20 had normal and 15 abnormal scores on the neonatal assessment. At 1 year 17 had normal and 18 abnormal scores. CONCLUSION: A normal visual assessment at term age is a good predictor of normal visual and neurodevelopmental outcome at 12 months. An abnormal visual examination in the neonatal period was a less reliable prognostic indicator, infant should be reassessed at 3 months.