Brain MRI findings and their association with visual impairment in young adolescents born very preterm.

PURPOSE: Very preterm birth increases risk for neonatal white matter injury, but there is limited data on to what extent this persists into adolescence and how this relates to ophthalmological outcomes. The aim of this study was to assess brain MRI findings in 12-year-old children born very preterm compared to controls and their association with concurrent ophthalmological outcomes. METHODS: We included 47 children born very preterm and 22 full-term controls (gestational age <32 and >37 weeks, respectively). Brain MRI findings were studied in association with concurrent ophthalmological outcomes at 12-year follow-up. RESULTS: Evans index (0.27 vs 0.25, p<0.001) and a proposed "posterior ventricle index" (0.47 vs 0.45, p=0.018) were increased in children born very preterm. Higher gestational age associated with larger corpus callosum area (ß=10.7, 95%CI 0.59-20.8). Focal white matter lesions were observed in 15 (32%) of very preterm children and in 1 (5%) of full-term controls. Increased posterior ventricle index increased risk for visual acuity ≤1.0 (OR=1.07×1011, 95%CI=7.78-1.48×1021) and contrast sensitivity <0.5 (OR=2.6×1027, 95%CI=1.9×108-3.5×1046). Decreased peritrigonal white matter thickness associated with impaired visual acuity (ß=0.04, 95%CI 0.002-0.07). CONCLUSION: More white matter lesions and evidence of lower white matter volume were found in children born very preterm compared with full-term controls at 12-year follow-up. The association between larger posterior ventricle index and reduced visual acuity and contrast sensitivity suggests disturbances of the posterior visual pathway due to diffuse white matter lesions.

Antenatal steroids and neurodevelopment in 12-year-old children born extremely preterm.

AIM: To investigate neurodevelopmental outcome in 12-year-old children born very preterm in relation to perinatal, neonatal and socioeconomic variables. To examine whether previously described positive effects of antenatal steroids on cognition persist at 12 years. METHODS: Prospective cohort, 78 children with gestational ages 22.7-31.9 weeks, born in 2004-2007 and examined at 12 years of age with cognitive, motor and visual motor integration tasks and compared to an age-matched control group (n = 50). Two preterm subgroups were studied: very preterm children (28-31 gestational weeks, n = 53) and extremely preterm children (22-27 gestational weeks, n = 25). RESULTS: The preterm children had significantly lower scores on all cognitive, motor and visual motor integration tasks than the controls. Gestational age and maternal education influenced associations differently in the two preterm subgroups. Also, severe retinopathy of prematurity demonstrated strong associations to outcome. In the extremely preterm group, administration of antenatal steroids was associated with better cognition, basic attention, word generation and motor skills. CONCLUSION: At 12 years of age, very preterm children born in the 2000s still have deficits across several neurodevelopmental domains compared to term-born peers. Administration of antenatal steroids has long-lasting associations to cognition and motor skills in extremely preterm-born children.

Using different definitions affected the reported prevalence of neurodevelopmental impairment in children born very preterm.

AIM: We investigated the impact of varying definitions on the prevalence of neurodevelopmental impairment (NDI) in children born very preterm at 6.5 years of age. METHODS: Cognitive development and neurosensory impairments were assessed in 91 children (40/51 girls/boys) born <32 gestational weeks, in 2004-2007 in Uppsala county, Sweden. The results were compared with data from a reference group of 67 children born full term. The prevalence of NDI in the present cohort was reported according to definitions used by seven contemporary studies of children born very or extremely preterm. RESULTS: The prevalence of severe NDI varied from 2% to 23% depending on the definition used. The prevalence of cognitive impairment varied from 2% (-3 SD according to test norms) to 16% (-2 SD according to control group), the prevalence of cerebral palsy from 0% (severe) to 9% (any) and the prevalence of severe visual impairment from 0% (blindness) to 1% (visual acuity < 0.3). There were no children with severe hearing impairment. CONCLUSION: A high variability in definitions affects the reporting of the prevalence of NDI in long-term follow-up studies of very or extremely preterm born children. There is a need for a better consensus to enable comparisons across studies.

National population-based cohort study found that visual-motor integration was commonly affected in extremely preterm born children at six-and-a-half years.

AIM: This study aimed to explain the relationship between visual-motor integration (VMI) abilities and extremely preterm (EPT) birth, by exploring the influence of perinatal variables, cognition, manual dexterity and ophthalmological outcomes. METHODS: This was part of the population-based national Extremely Preterm Infant Study in Sweden (EXPRESS) study. We studied 355 children, born at a gestational age of <27 weeks from April 2004 to March 2007, and 364 term-born controls. At six-and-a-half years of age, we assessed VMI, cognitive function, motor skills and vision. VMI impairment was classified as <-1 standard deviation (SD). RESULTS: The mean (SD) VMI score was 87 (±12) in preterm children compared to 98 (±11) in controls (p < 0.001). VMI impairment was present in 55% of preterm infants and in 78% of children born at 22-23 weeks. Male sex and postnatal steroids showed a weak association with poorer visual-motor performance, whereas low manual dexterity and cognitive function showed a stronger association. CONCLUSION: Poor VMI performance was common in this EXPRESS cohort of children born EPT. Its strong association to cognition and manual dexterity confirms that all of these factors need to be taken into account when evaluating risks in preterm born children.

Impaired cognitive ability at 2.5 years predicts later visual and ophthalmological problems in children born very preterm.

AIM: To identify possible predictive factors for visual problems at 6.5 years in children born very preterm. METHODS: During 2004-2007, all very preterm infants (gestational age [GA] <32 weeks) in Uppsala County, Sweden were screened for retinopathy of prematurity (ROP) neonatally; at four months, visual tracking was tested; at 2.5 years, visuospatial and cognitive tests were carried out. At 6.5 years, 84 preterm children and a reference group of 64 full-term children underwent ophthalmological testing. RESULTS: Mean visual acuity (VA) did not differ between the groups, but subnormal VA (≤0.8) was more common in the preterm group (31% vs 14%; p < 0.05). More often than full-term children, preterm children had impaired contrast sensitivity (<0.5) (36% vs 19%; p < 0.05) and strabismus (8% vs 0%; p < 0.05). Low GA, ROP, intraventricular haemorrhage 3-4/periventricular leukomalacia and cognitive disability at 2.5 years predicted ophthalmological and visual problems at 6.5 years. Visual tracking ability at four months was not predictive of ophthalmological outcome. CONCLUSION: Children born preterm had more ophthalmological problems at 6.5 years of age, including subtle dysfunctions. ROP, early brain injury and impaired cognitive function around 2.5 years predicted later ophthalmological dysfunctions.