Atypical perceptual narrowing in prematurely born infants is associated with compromised language acquisition at 2 years of age

Background: Early auditory experiences are a prerequisite for speech and language acquisition. In healthy children, phoneme discrimination abilities improve for native and degrade for unfamiliar, socially irrelevant phoneme contrasts between 6 and 12 months of age as the brain tunes itself to, and specializes in the native spoken language. This process is known as perceptual narrowing, and has been found to predict normal native language acquisition. Prematurely born infants are known to be at an elevated risk for later language problems, but it remains unclear whether these problems relate to early perceptual narrowing. To address this question, we investigated early neurophysiological phoneme discrimination abilities and later language skills in prematurely born infants and in healthy, full-term infants. Results: Our follow-up study shows for the first time that perceptual narrowing for non-native phoneme contrasts found in the healthy controls at 12 months was not observed in very prematurely born infants. An electric mismatch response of the brain indicated that whereas full-term infants gradually lost their ability to discriminate non-native phonemes from 6 to 12 months of age, prematurely born infants kept on this ability. Language performance tested at the age of 2 years showed a significant delay in the prematurely born group. Moreover, those infants who did not become specialized in native phonemes at the age of one year, performed worse in the communicative language test (MacArthur Communicative Development Inventories) at the age of two years. Thus, decline in sensitivity to non-native phonemes served as a predictor for further language development. Conclusion: Our data suggest that detrimental effects of prematurity on language skills are based on the low degree of specialization to native language early in development. Moreover, delayed or atypical perceptual narrowing was associated with slower language acquisition. The results hence suggest that language problems related to prematurity may partially originate already from this early tuning stage of language acquisition

Haemoglobin level at birth is associated with short term outcomes and mortality in preterm infants

Background Blood volume and haemoglobin (Hb) levels are increased by delayed umbilical cord clamping, which has been reported to improve clinical outcomes of preterm infants. The objective was to determine whether Hb level at birth was associated with short term outcomes in preterm infants born at ≤32 weeks gestation. Methods Data were collected retrospectively from electronic records: Standardised Electronic Neonatal Database, Electronic Patient Record, Pathology (WinPath), and Blood Bank Electronic Database. The study was conducted in a tertiary perinatal centre with around 5,500 deliveries and a neonatal unit admission of 750 infants per year. All inborn preterm infants of 23 to 32 weeks gestational age (GA) admitted to the neonatal unit from January 2006 to September 2012 were included. The primary outcomes were intra-ventricular haemorrhage, necrotising entero-colitis, broncho-pulmonary dysplasia, retinopathy of prematurity, and death before discharge. The secondary outcomes were receiving blood transfusion and length of intensive care and neonatal unit days. The association between Hb level (g/dL) at birth and outcomes was analysed by multiple logistic regression adjusting for GA and birth weight (BWt). Results Overall, 920 infants were eligible; 28 were excluded because of missing data and 2 for lethal congenital malformation. The mean (SD) GA was 28.3 (2.7) weeks, BWt was 1,140 (414) g, and Hb level at birth was 15.8 (2.6) g/dL. Hb level at birth was significantly associated with all primary outcomes studied (P <0.001) in univariate analyses. Once GA and BWt were adjusted for, only death before discharge remained statistically significant; the OR of death for infants with Hb level at birth <12 g/dL compared with those with Hb level at birth of ≥18 g/dL was 4.1 (95% CI, 1.4–11.6). Hb level at birth was also significantly associated with blood transfusion received (P <0.01) but not with duration of intensive care or neonatal unit days. Conclusions Low Hb level at birth was significantly associated with mortality and receiving blood transfusion in preterm infants born at ≤32 weeks gestation. Further studies are needed to determine the association between Hb level at birth and long-term neurodevelopmental outcomes

Perinatal brain damage in very preterm infants:prenatal inflammation and neurologic outcome in children born term and preterm

Abstract Despite improvements in peri- and neonatal care and an increase in the overall survival of very preterm infants, the incidence of neurologic sequelae has remained high. The pathogenesis of many brain imaging findings, such as white matter damage, WMD, is poorly understood. The factors predisposing to brain damage differ between term and preterm infants. More detailed information is needed of how brain imaging correlates with neurodevelopmental impairment after the neonatal period. The present study investigated the pre- and perinatal factors leading to brain damage and their effects on neurologic and neurodevelopmental outcome in very preterm children. We also analyzed the differences in umbilical cord serum cytokines in term and preterm children with cerebral palsy, CP. Furthermore, the correlations between the findings on diffusion-weighted imaging, DWI, measurements in brainstem auditory evoked potentials, and neurodevelopmental outcome were assessed. We demonstrated that pregnancies complicated by combined histologic chorioamnionitis and placental insufficiency independently predicted abnormal neurologic outcome at 2 years of corrected age. WMD additively predicted poor outcome. Isolated fetal inflammatory response, umbilical cord serum acute phase cytokines (IL-1α, IL-1β, IL-6, IL-8, TNF-α), did not associate with neurologic outcome in either term or preterm children. Instead, a cluster of cytokines different from acute phase cytokines were related to CP, and the protein profile differed between term and preterm children. Disturbed hemodynamics during the pre- and perinatal period affected outcome in very preterm infants. In severe placental insufficiency, fetal cardiac compromise associated with suboptimal neurodevelopmental outcome at 1 year of corrected age. In addition, several clinical factors characterising cardiorespiratory status after birth associated with abnormal neurologic outcome at 2 years of corrected age. We found the apparent diffusion coefficient, ADC, a quantitative measurement of water diffusion, in pons to correlate with the conduction rate of impulses travelling through the auditory tract. We also demonstrated a high value of ADC in corona radiata to associate with poor outcome in gross motor and eye-hand coordination skills at 2 years of corrected age. Both pre- and perinatal factors associate with later outcome in very preterm infants. An isolated fetal inflammatory response does not predict neurologic outcome. Findings on DWI in specific brain regions predict abnormal neurodevelopmental outcome.Tiivistelmä Huolimatta vastasyntyneisyyskauden parantuneista hoitotuloksista ja että yhä useampi hyvin ennenaikaisena syntynyt lapsi jää eloon, heidän neurologisen vammautuneisuuden ilmaantuvuus on edelleen korkea. Monien aivojen kuvantamislöydösten, kuten valkean aineen vaurion, syntymekanismit tunnetaan huonosti. Aivojen vaurioitumiselle altistavat tekijät eroavat täysiaikaisena ja ennenaikaisena syntyneillä lapsilla. Tarvitaan myös aiempaa yksityiskohtaisempaa tietoa aivojen kuvantamislöydösten merkityksestä lasten vastasyntyneisyyskauden jälkeiseen kehitykseen. Tässä tutkimuksessa selvitettiin raskauden- ja syntymänaikaisia tekijöitä, jotka vaikuttavat aivojen vaurioitumiseen hyvin ennenaikaisena syntyneillä lapsilla sekä näiden tekijöiden merkitystä lasten neurologiseen kehitykseen. Tarkastelimme myös napaveren seerumin välittäjäaineiden, sytokiinien, eroavuuksia täysiaikaisena ja ennenaikaisena syntyneillä CP-lapsilla. Lisäksi selvitimme diffuusiomagneettitutkimus- ja aivorunkoherätevastelöydösten sekä neurologisen kehityksen välisiä yhteyksiä. Tämän tutkimuksen mukaan kohdunsisäinen tulehdus ja istukan vajaatoiminta yhtä aikaa esiintyessään ovat poikkeavan neurologisen kehityksen itsenäisiä riskitekijöitä lapsilla 2 vuoden korjatussa iässä tutkittuna. Valkoisen aivoaineen vaurio edelleen lisäsi näiden lasten huonon neurologisen kehityksen ennustetta. Raskauden kestosta riippumatta, sikiön tulehdusvastetta kuvaavat napaveren akuutin vaiheen tulehdusvälittäjäaineet (IL-1α, IL-1β, IL-6, IL-8, TNF- α) eivät vaikuttaneet lapsen neurologiseen kehitykseen. Sen sijaan, CP-lasten napaverestä löytyi erityinen joukko ei-akuutin vaiheen välittäjäaineita. Nämä valkuaisaineet erosivat toisistaan täysiaikaisena ja ennenaikaisena syntyneillä CP-lapsilla. Raskauden- ja syntymänaikaiset verenkierron häiriöt vaikuttivat hyvin ennenaikaisena syntyneiden lasten myöhempään kehitykseen. Vaikeassa istukan vajaatoiminassa sikiön sydämen toiminnan heikkeneminen liittyi lapsen suboptimaaliin neurologiseen kehitykseen 1 vuoden korjatussa iässä tutkittuna. Lisäksi useat syntymänjälkeiset keuhkojen ja verenkierron tilaa kuvaavat kliiniset tekijät liittyivät lapsen poikkeavaan neurologiseen kehitykseen 2 vuoden korjatussa iässä tutkittuna. Tutkimuksemme mukaan, veden diffuusiota määrällisesti kuvaava diffuusiokerroin, ADC, aivosillasta mitattuna, liittyi impulssien johtumisnopeutueen kuuloradastossa. Lisäksi korkea ADC-arvo aivojen sepelviuhkassa liittyi karkean motoriikan ja silmä-käsi-yhteistyötaitojen huonoon kehitykseen 2 vuoden korjatussa iässä tutkittuna. Sekä raskauden- että syntymänaikaiset tekijät vaikuttavat hyvin ennenaikaisena syntyneiden lasten myöhempään kehitykseen. Yksittäinen sikiön tulehdusvaste ei ennakoi lapsen neurologista kehitystä. Tiettyjen aivoalueiden diffuusiokuvantamislöydökset ennustavat lapsen poikkeavaa neurologista kehitystä

Randomized trial of early erythropoietin supplementation after preterm birth: Iron metabolism and outcome

Background Excess of iron and oxidant injury shortly after birth may be associated with neonatal morbidities in preterm infants. Aims The aim was to determine whether administration of erythropoietin without iron supplementation decreases iron load and morbidity. Study design and subjects In a randomized trial, we administered erythropoietin (EPO 250 IU/kg daily during the first 6 days of life) or placebo to 39 preterm infants (BW 700–1500 g, GA ≤ 30.0 weeks). Outcome measures The iron status, postnatal morbidities and follow-up at the age of two years were investigated. Results In all, 21 EPO- and 18 placebo-treated infants were recruited. A requirement of red blood cell transfusions during first 28 days was similar between the study groups. EPO treatment decreased total serum iron concentration (p = 0.035). EPO supplementation had no significant effect on serum transferrin receptors or reactive non-protein-bound iron. There were no differences in neonatal morbidity or in survival without major neurological abnormality at two years of age. Conclusions A 6-day course of EPO decreased the iron load in preterm infants. There was no change in reactive, non-protein bound iron plasma levels and no influence on the outcomes during early childhood. Whether the neurocognitive effects of early EPO treatment can be detectable later in childhood remained to be verified

Diffusion tensor imaging in frontostriatal tracts is associated with executive functioning in very preterm children at 9 years of age

Abstract Background: Very preterm birth can disturb brain maturation and subject these high-risk children to neurocognitive difficulties later. Objective: The aim of the study was to evaluate the impact of prematurity on microstructure of frontostriatal tracts in children with no severe neurologic impairment, and to study whether the diffusion tensor imaging metrics of frontostriatal tracts correlate to executive functioning. Materials and methods: The prospective cohort study comprised 54 very preterm children (mean gestational age 28.8 weeks) and 20 age- and gender-matched term children. None of the children had severe neurologic impairment. The children underwent diffusion tensor imaging and neuropsychological assessments at a mean age of 9 years. We measured quantitative diffusion tensor imaging metrics of frontostriatal tracts using probabilistic tractography. We also administered five subtests from the Developmental Neuropsychological Assessment, Second Edition, to evaluate executive functioning. Results: Very preterm children had significantly higher fractional anisotropy and axial diffusivity values (P&lt;0.05, corrected for multiple comparison) in dorsolateral prefrontal caudate and ventrolateral prefrontal caudate tracts as compared to term-born children. We found negative correlations between the diffusion tensor imaging metrics of frontostriatal tracts and inhibition functions (P&lt;0.05, corrected for multiple comparison) in very preterm children. Conclusion: Prematurity has a long-term effect on frontostriatal white matter microstructure that might contribute to difficulties in executive functioning

Microstructural alterations in association tracts and language abilities in schoolchildren born very preterm and with poor fetal growth

Abstract Background: Prematurity and perinatal risk factors may influence white matter microstructure. In turn, these maturational changes may influence language development in this high-risk population of children. Objective: To evaluate differences in the microstructure of association tracts between preterm and term children and between preterm children with appropriate growth and those with fetal growth restriction and to study whether the diffusion tensor metrics of these tracts correlate with language abilities in schoolchildren with no severe neurological impairment. Materials and methods: This study prospectively followed 56 very preterm children (mean gestational age: 28.7 weeks) and 21 age- and gender-matched term children who underwent diffusion tensor imaging at a mean age of 9 years. We used automated probabilistic tractography and measured fractional anisotropy in seven bilateral association tracts known to belong to the white matter language network. Both groups participated in language assessment using five standardised tests at the same age. Results: Preterm children had lower fractional anisotropy in the right superior longitudinal fasciculus 1 compared to term children (P &lt; 0.05). Preterm children with fetal growth restriction had lower fractional anisotropy in the left inferior longitudinal fasciculus compared to preterm children with appropriate fetal growth (P &lt; 0.05). Fractional anisotropy in three dorsal tracts and in two dorsal and one ventral tract had a positive correlation with language assessments among preterm children and preterm children with fetal growth restriction, respectively (P &lt; 0.05). Conclusions: There were some microstructural differences in language-related tracts between preterm and term children and between preterm children with appropriate and those with restricted fetal growth. Children with better language abilities had a higher fractional anisotropy in distinct white matter tracts

Apolipoprotein E, brain injury and neurodevelopmental outcome of children

Apolipoprotein E plays an important role in neurodegenerative processes in adulthood, whereas its neurodevelopmental role is uncertain. We aimed to study the effect of apolipoprotein E on neurodevelopment in a cohort liable to neurodevelopmental changes. The cohort consisted of very preterm (<32 gestational weeks) and/or very low birth weight (<1500g) children, and the longitudinal follow-up protocol included sequential cranial ultrasounds during infancy, brain magnetic resonance imaging at term-equivalent age, neurological and cognitive assessment (Mental Developmental Index) at the corrected age of 2 years and cognitive and neuropsychological assessments (Wechsler Preschool and Primary Scale of Intelligence and Developmental NEuroPSYchological Assessment) at the chronological age of 5 years. Apolipoprotein E genotypes were determined from 322 children. Ultrasound and magnetic resonance imaging data were available for 321 (99.7%) and 151 (46.9%) children, respectively. Neurodevelopmental assessment data were available for 138 (42.9%) to 171 (53.1%) children. Abnormal findings in ultrasounds and magnetic resonance imaging were found in 163 (50.8%) and 64 (42.4%) children, respectively. Mild cognitive delay at the corrected age of 2 years and the chronological age of 5 years was suspected in 21 (12.3%) of 171 and 19 (13.8%) of 138 children, respectively. In the Developmental NEuroPSYchological Assessment, 47 (32.6%) of 144 children had significantly impaired performances in more than one study subtest. No associations between the apolipoprotein E genotypes and imaging findings or measured neurodevelopmental variables were found. Apolipoprotein E genotypes do not appear to have major impact on brain vulnerability or neurodevelopment in children.5 page(s