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

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 < 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 < 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 < 0.05).

CONCLUSION

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.

Antenatal and neonatal risk factors in very preterm children were associated with language difficulties at nine years of age

AIM

This Finnish study compared language and reading abilities between schoolchildren born at a very low gestational age (VLGA) of <32 weeks and at term and analysed any associations between antenatal and neonatal risk factors and language skills in the VLGA group.

METHODS

We prospectively followed 76 children born at a VLGA and 50 children born at term when they reached a mean age of 9.0 (8.1-10.0) years. They attended mainstream schools and had no severe neurosensory disabilities. Receptive language ability, rapid naming and word reading were evaluated using standardised tests.

RESULTS

Children in the VLGA group had lower scores for receptive language abilities (median 55.0 versus 57.0, p = 0.01) and word reading (mean 4.4 versus 5.1, p = 0.03) than the children in the term group. In the VLGA group, foetal growth restriction was associated with lower scores for rapid naming, early intraventricular haemorrhage was associated with poor word reading and respiratory distress syndrome was associated with poor rapid naming (p < 0.05).

CONCLUSION

Schoolchildren born at a VLGA had more difficulties with receptive language abilities and word reading than children born at term. Foetal growth restriction and early neonatal morbidities were associated with language difficulties.

Children born before 32 weeks of gestation displayed impaired reading fluency, comprehension and spelling skills at 9 years of age

AIM

Our aim was to study whether prematurity, associated with prenatal and neonatal risk factors, affects specific literacy skills among school children born at a very low gestational age (VLGA) of <32 weeks.

METHODS

The study group comprised 76 prospectively followed VLGA children born between November 1998 and November 2002 at Oulu University Hospital, Finland, and 51 term controls. The median gestational age of the VLGA children was 29.0 (24.1-31.9) weeks. All children were examined at a median age of 8.9 (8.0-9.9) years in Oulu between November 2007 and November 2011. Reading fluency, comprehension and spelling skills were evaluated using standardised tests for Finnish-speaking children.

RESULTS

Very low gestational age children had significantly poorer test results in reading comprehension (median 6.9 vs 8.3, P = .014) and spelling (median 35.7 vs 38.0, P = .013) than term children. Furthermore, VLGA children more often performed below the 10th percentile normal values in spelling (P = .012) compared with term controls. Foetal growth restriction was associated with lower scoring in reading fluency (P = .023) and spelling (P = .004) among VLGA children.

CONCLUSION

Very low gestational age school children performed poorer in reading comprehension and spelling than term children. In addition, poor foetal growth in VLGA children was associated with literacy problems.

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

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<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<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.

Microbiome of the first stool and overweight at age 3 years: A prospective cohort study

BACKGROUND

Several reports have revealed that the first-pass meconium hosts a diverse microbiome, but its clinical significance is not known.

OBJECTIVE

We designed a prospective population-based cohort study to evaluate whether the meconium microbiome predicts subsequent growth in children.

METHODS

The study comprised 212 consecutive newborns with a meconium sample and a follow-up sample at 1 year of age. Trained nurses measured the children for weight and length using standardized techniques. We used next-generation sequencing of bacterial 16S rRNA gene and machine-learning approach for the analysis.

RESULTS

The children with overweight at 3 years of age differed in their meconium microbiome from those with normal weight, having a higher proportion of Bacteroidetes phylum (29% vs 15%, P = .013). Using the machine-learning approach, the gut microbiome at birth predicted subsequent overweight with area under the curve 0.70 (SD 0.04). A lower proportion of Staphylococcus at birth was associated with greater length/height at 1 year (ß = -.68, P = .029) and 2 years of age (β = -.74, P = .030).

CONCLUSIONS

The microbiome of the first-pass meconium predicted subsequent overweight at the age of 3 years. The association between the gut microbiome and overweight appears to start already during pregnancy and at birth.

Maternal influence on the fetal microbiome in a population-based study of the first-pass meconium

BACKGROUND

Meconium is formed before birth and may reflect the microbiome of the fetus. To test our hypothesis, we investigated whether maternal factors during pregnancy, such as biodiversity of the living environment, influence the microbiome of the first stool more than immediate perinatal factors.

METHODS

We recruited 218 consecutive newborn infants from one hospital. Regions of the bacterial 16S rRNA gene were sequenced to characterize the microbiomes of the first-pass meconium samples (N=212). We used a multivariate model to determine both the prenatal and perinatal factors affecting the microbiome.

RESULTS

The number of operational taxonomic units ranged from 0 to 448 per newborn. The most abundant phyla were Firmicutes, with a relative abundance of 44%, Proteobacteria, 28%, and Bacteroidetes, 15%. By a multivariate analysis, the biodiversity of the home environment increased the diversity of microbiomes, whereas perinatal factors, such as the delivery mode or exposure to antimicrobials during labor did not have an effect.

CONCLUSION

The microbiome of the first-pass meconium was not altered by immediate perinatal factors, but was affected by maternal factors during pregnancy, implying the in utero transfer of microbes and the development of the gut microbiota niche in fetal life.

Very preterm children with fetal growth restriction demonstrated altered white matter maturation at nine years of age

AIM

This study evaluated the role of preterm birth and fetal growth restriction on white matter maturation in schoolchildren without any severe neurodevelopmental impairment.

METHODS

The study group comprised 56 very preterm children and 21 term children born between November 1998 and November 2002 at Oulu University Hospital, Finland. The mean gestational age of the preterm children was 28.7 (24.1-31.9) weeks. All children underwent diffusion tensor imaging at a mean age of 9.0 (8.6-9.6) years. Voxel-wise statistical analyses of the imaging data were carried out using tract-based spatial statistics.

RESULTS

Preterm children with fetal growth restriction had lower fractional anisotropy and higher radial diffusivity than term controls (p < 0.05), bilaterally in several white matter areas. Preterm children without fetal growth restriction had higher mean diffusivity and axial diffusivity than term controls (p < 0.05) in analogous areas, but more asymmetrically.

CONCLUSION

Preterm children had microstructural differences in white matter, compared to term-born children at a mean age of nine, and those with poor fetal growth showed widespread changes in white matter maturation compared to term-born children. Fetal growth and prematurity seemed to affect white matter maturation in a way that was still visible at that age.

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 250IU/kg daily during the first 6days of life) or placebo to 39 preterm infants (BW 700-1500g, GA≤30.0weeks).

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 28days 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.

School-age children enjoyed good respiratory health and fewer allergies despite having lung disease after preterm birth

AIM

This study explored the under-researched area of whether preterm birth or bronchopulmonary dysplasia (BPD) affected hospitalisation rates, allergies or health-related quality of life (HRQoL).

METHODS

We studied 88 schoolchildren born preterm at a mean gestational age of 28.8 weeks (range 24.1-31.9) and matched term-born controls at the mean age of 11 years (range 8-14). Hospitalisations after the first discharge were recorded, skin prick allergy tests were performed and HRQoL was assessed with a parental questionnaire.

RESULTS

Preterm children were hospitalised more than controls (64% versus 39%, p = 0.001), mostly before two years of age. The adjusted odds ratios (OR) for two-year-old preterm-born children being hospitalised for wheezing was 8.2 (95% CI 2.0-34.1). BPD affected 56% of the preterm children, but did not influence hospitalisations, and the positive skin prick rate was similar between the preterm and term-born children (35% versus 48%, p = 0.126). Preterm BPD children had fewer positive skin prick tests than those without BPD. HRQoL was lower in preterm than term children (81.25 ± 10.84 versus 86.80 ± 9.60, p = 0.001).

CONCLUSION

Most health problems experienced by preterm-born schoolchildren occurred before two years of age and were mainly wheezing disorders. BPD decreased atopy but had no influence on hospitalisation rates.

Intrauterine growth restriction predicts lower lung function at school age in children born very preterm

OBJECTIVE

Children born preterm have lower lung function compared with term-born children. Intrauterine growth restriction (IUGR) may predispose individuals to chronic obstructive pulmonary disease. The purpose of this observational study was to investigate the role of IUGR as predictor of lung function at school age in children born very preterm. We further studied the difference in lung function between term-born and preterm-born children with distinct morbidities.

DESIGN

Preterm-born children and age-matched and sex-matched term-born comparison groups (88 of each) were studied at the mean age of 11 years. Spirometry and diffusing capacity of the lung for carbon monoxide (DLCO) were recorded. All preterm-born subjects with IUGR (n=23), defined as birth weight less than -2 SD, were compared with preterm-born subjects without IUGR (n=65).

RESULTS

In the preterm-born children exposed to IUGR, the forced expiratory volume in 1 s (FEV1) was 5.7 (95% CI -10.2 to -1.3) and DLCO 9.2 percentage points lower (95% CI -15.7 to -2.7) than in the preterm-born children with appropriate in utero growth (expressed as percentage of predicted values). The effect of IUGR in decreasing FEV1 and DLCO remained significant after adjustment for bronchopulmonary dysplasia (BPD). Further study indicated that after adjustment with IUGR and BPD, prematurity explained reduction in FEV1 but not in DLCO.

CONCLUSIONS

In children born very preterm, IUGR is an independent risk factor for a lower lung function in school age. We propose that IUGR and BPD are the major early factors predisposing the children born very preterm to lower lung function.

New BPD predicts lung function at school age: Follow-up study and meta-analysis

New treatment practices have improved survival of preterm infants and decreased airway pathology in bronchopulmonary dysplasia (BPD). Our aim was to investigate whether preterm birth, BPD, and the severity of BPD predict lung function in school children that are born in surfactant era. We studied pulmonary function of 88 school-aged children born very preterm (gestational age <32 weeks) and paired them with 88 age- and sex-matched controls born at term. Spirometry and diffusion capacity were recorded. We also performed a meta-analysis covering the era of antenatal corticosteroid and surfactant treatment. BPD was defined as oxygen dependence for ≥ 28 days and it was severity-graded by oxygen requirement at 36 weeks postmenstrual age (mild, none; moderate, FiO2 = 0.22-0.29; severe, FiO2 ≥ 0.30). Preterm children had lower forced expiratory volume in 1 sec (FEV1 ) 86.4 ± 11.8 versus 94.9 ± 10.1 (mean % predicted ± SD; P < 0.001), and lower diffusion capacity (DLCO) 87.6 ± 13.9 versus 93.7 ± 12.0 (P = 0.005) compared with term controls. BPD group differed in both FEV1 (P = 0.037) and DLCO (P = 0.018) from those without BPD. For meta-analysis, search identified 210 articles. Together with present results, six articles met the inclusion criteria. FEV1 of no BPD, all BPD, and moderate to severe BPD groups differed from that in term controls by -7.4, -10.5, and -17.8%, respectively. According to meta-analysis and follow-up study, the adverse effects of prematurity on pulmonary function are still detectable in school-age. BPD was associated with reductions in both diffusion capacity and spirometry. New interventions are required to document a further decrease in the life-long consequences of prematurity.

CXCR3 Polymorphism and Expression Associate with Spontaneous Preterm Birth

Spontaneous preterm birth (SPTB) is a major factor associating with deaths and with lowered quality of life in humans. Environmental and genetic factors influence the susceptibility. Previously, by analyzing families with recurrent SPTB in linkage analysis, we identified a linkage peak close to the gene encoding CXCR3. Present objectives were to investigate the association of CXCR3 with SPTB in Finnish mothers (n = 443) and infants (n = 747), to analyze CXCR3 expression levels in human placenta and levels of its ligands in umbilical cord blood, and to verify the influence of Cxcr3 on SPTB-associating cytokines in mice. We detected an association between an intronic CXCR3 polymorphism, rs2280964, and SPTB in infants from families with recurrent preterm births (p = 0.009 versus term controls, odds ratio 0.52, 95% confidence interval 0.32-0.86). The minor allele was protective and undertransmitted to SPTB infants (p = 0.007). In the placenta and fetal membranes, the rs2280964 major allele homozygotes had higher expression levels than minor allele homozygotes; decidual trophoblasts showed strong CXCR3 immunoreactivity. Expression was higher in SPTB placentas compared with those from elective deliveries. Concentration of a CXCR3 ligand, CXCL9, was increased in cord blood from SPTB, and the protective rs2280964 allele was associated with low CXCL9. In CXCR3-deficient mice (Mus musculus), SPTB-associating cytokines were not acutely increased in amniotic fluid after preterm birth-inducing dose of maternal LPS. Our results indicate that CXCR3 contributes to SPTB. Activation of CXCR3 signaling may disturb the maternal-fetal tolerance, and this may promote labor.

Polymorphisms of the gene encoding Kit ligand are associated with bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic inflammatory lung disease that affects infants born preterm. Family studies indicate that BPD has a significant genetic component.

RATIONALE

We assessed the gene encoding Kit ligand (KITLG) as a candidate for genetic predisposition to moderate-to-severe BPD (controls were infants with no or mild BPD).

STUDY DESIGN

Eight KITLG-tagging single nucleotide polymorphisms (SNPs) were analyzed in cohorts of very preterm infants originating from northern Finland (56 cases and 197 controls), southern Finland (n = 59 + 52), and Canada (n = 58 + 68). Additional replication populations included infants born in Finland (n = 41 + 241) and Hungary (n = 29 + 40). All infants were of European origin. Results were controlled for risk factors of BPD. Kit ligand concentration in umbilical cord blood, collected from very preterm infants (n = 120), was studied.

RESULTS

Six SNPs of KITLG and a haplotype including all eight genotyped SNPs were associated with moderate-to-severe BPD in the northern Finnish population. When all the populations were combined, SNP rs11104948 was significantly associated with BPD. Kit ligand concentration in umbilical cord blood of infants born very preterm was an independent risk factor of BPD.

CONCLUSIONS

We show that KITLG polymorphisms are associated with susceptibility to moderate-to-severe BPD. In addition, higher Kit ligand concentrations were observed in infants that subsequently developed BPD. These results support the possibility that KITLG gene is involved in predisposition to BPD. Pediatr Pulmonol. 2015; 50:260-270. © 2014 Wiley Periodicals, Inc.

Genes Encoding Vascular Endothelial Growth Factor A (VEGF-A) and VEGF Receptor 2 (VEGFR-2) and Risk for Bronchopulmonary Dysplasia

BACKGROUND

Bronchopulmonary dysplasia (BPD) is one of the main consequences of prematurity, with notably high heritability. Vascular endothelial growth factor A (VEGF-A) and its main receptor, vascular endothelial growth factor receptor 2 (VEGFR-2), have been implicated in the pathogenesis of BPD.

OBJECTIVE

To study whether common polymorphisms of the genes encoding VEGF-A and VEGFR-2 are associated with BPD.

METHODS

In this association study, six tagging single nucleotide polymorphism (tSNPs) for VEGFA and 25 tSNPs for VEGFR2 were genotyped in a prospectively collected, genetically homogeneous discovery population of 160 infants (44 infants with grade 2-3 BPD) born before 30 completed gestational weeks. The replication population of 328 infants included 120 cases of BPD.

RESULTS

VEGFR2 SNP rs4576072 was associated with BPD grade 2-3 with a minor allele frequency in 23.9% of the cases compared to 9.1% in controls (p = 0.0005, odds ratio 3.15, 95% CI: 1.62-6.12) in the discovery population. This association was not observed in the more heterogeneous replication population.

CONCLUSIONS

In line with the results of recent large-scale genetic studies, our findings indicate that common polymorphisms of the genes encoding VEGF-A and VEGFR-2 are not consistently associated with BPD. This finding does not rule out the involvement of VEGFA and VEGFR2 in BPD pathogenesis since, in addition to common variations within the gene region, other mechanisms also play important roles in the regulation of gene function.

Cerebral Palsy and Polymorphism of the Chemokine CCL18 in Very Preterm Children

BACKGROUND

Prematurity and hereditary factors predispose to cerebral palsy (CP). Previously, low cord blood levels of the anti-inflammatory chemokine CCL18 have been found to be associated with risk of CP in preterm children.

OBJECTIVES

To investigate the association between single nucleotide polymorphisms (SNPs) in CCL18 and susceptibility to CP, as well as the association between the SNPs and cord blood levels of CCL18.

METHODS

The original population comprised very-low-gestational-age (VLGA; <32 weeks) children from northern and central Finland (25 cases, 195 controls). Five CCL18 SNPs were genotyped and examined for associations with CP and cord blood CCL18. The replication population comprised Caucasian VLGA children from southern Finland and Canada (23 cases, 248 controls).

RESULTS

In the original population, SNP rs2735835 was associated with CP; the minor allele A was underrepresented in cases compared to controls (OR = 0.42, 95% CI: 0.21-0.83, p = 0.01). This association remained significant after adjustment for multiple testing and risk factors of CP, and after combining the original and replication populations (OR = 0.52, 95% CI: 0.33-0.83, p = 0.005). Intraventricular hemorrhage (IVH) additively predicted CP. The Rs2015086 genotype was modestly associated with CCL18 concentration.

CONCLUSIONS

A common CCL18 polymorphism together with IVH had an additive influence on CP susceptibility. Developmentally regulated CCL18, confined to primates, may be involved in the complex sequence of events leading to brain injury and predisposition to CP phenotype.

Very preterm birth and foetal growth restriction are associated with specific cognitive deficits in children attending mainstream school

AIM

This study investigated the association of prenatal and neonatal factors with cognitive outcomes in schoolchildren born very preterm without impairments at the age of nine.

METHODS

We recruited a prospective regional cohort of 154 very low gestational age (VLGA) children of <32 weeks and 90 term-born comparison children born between November 1998 and November 2002 at Oulu University Hospital, Finland. Cognitive outcome was assessed using an inclusive neuropsychological test repertoire at the age of nine.

RESULTS

The final study group comprised 77 VLGA children without cerebral palsy or any cognitive impairment and 27 term-born children. VLGA was associated with a 1.5-point [95% confidence interval (CI) 0.6-2.3] reduction in visuospatial-sensorimotor processing and a 1.2-point (95% CI 0.5-1.9) reduction in attention-executive functions scores. Foetal growth restriction (FGR) was the only clinical risk factor that was associated with cognitive outcome. Children with FGR had a significant decrease in language (1.7 points, 95% CI 0.50-3.0) and memory-learning (1.6 points, 95% CI 0.4-2.8) scores.

CONCLUSION

Children born very preterm without impairments had poorer performance in specific neurocognitive skills than term-born children. FGR was an independent risk factor for compromised neurocognitive outcome in VLGA children and predicted difficulties in language, memory and learning.

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 (<1500 g) 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.

Perinatal immunoproteins predict the risk of cerebral palsy in preterm children

OBJECTIVE

To investigate whether blood cytokines during the perinatal period predict the risk of cerebral palsy (CP) in preterm infants.

METHODS

This prospective cohort study comprised 169 children born before 32 weeks of gestation. Cord blood was drawn at birth, and 109 cytokines were analyzed using microarrays. Eleven cytokines were further measured from both cord and peripheral blood on days 1 and 7. Cerebral palsy was confirmed at 5 years of age.

RESULTS

Cerebral palsy was diagnosed in 19 children. Five clusters of cord blood cytokines were scored using factor analysis. According to logistic regression analysis, the scores of factors 1 and 2 independently predicted the risk of CP. These cytokines included several growth factors and chemokines, and they all tended to be higher in children with CP than in children without CP. Inflammatory cytokine levels were associated with CP risk on days 1 and 7 after birth.

CONCLUSION

The high blood concentrations of various cytokines during the perinatal period may relate to CP, and these cytokines may influence the pathways leading to early insult in the central nervous system. The risk profile of inflammatory cytokines is different at birth than during the first week after birth.

Cord blood chemokines differentiate between spontaneous and elective preterm births in singleton pregnancies

BACKGROUND

Signals originating from both maternal and fetal compartments participate in the preterm labor process.

OBJECTIVE

To investigate whether cord blood immunoproteins predict spontaneous preterm labor.

METHODS

Cord blood from 125 very preterm (gestational age <32weeks) singleton infants and 33 term infants was collected after birth and analyzed for 107 immunoproteins on microarrays. Immunoproteins from spontaneous preterm births (SPTB) were compared to immunoproteins from preterm births without labor. The placentas were studied for histology and immunohistochemistry. The data was modeled by classification and regression trees (CART) analysis.

RESULTS

In preterm births, low CCL16 level predicted SPTB with a sensitivity of 94.7%, and specificity of 46.9%. According to logistic regression analysis, low CCL16 (OR 57.9), histologic chorioamnitis (OR 33.6), and high CCL23 (OR 44.6) were independent risk factors of SPTB. Cord blood CCL16 was higher in preterm births without labor and in term births than in SPTBs. CCL16 and its signaling receptor CCR1 were visualized in syncytiotrophoblast and cytotrophoblast cells of placental villi.

CONCLUSION

Low umbilical cord blood chemokine CCL16 associates with spontaneous preterm birth. Further studies are required to show whether CCL16 is involved in spontaneous preterm labor or in placental disease necessitating elective preterm delivery.

Chemokine CCL18 predicts intraventricular hemorrhage in very preterm infants

BACKGROUND

Intraventricular hemorrhage (IVH) in very preterm infants is a common disease associated with long-term consequences. Risk factors of IVH remain to be further defined.

AIMS

To determine whether specific immunoproteins at birth predict the risk of IVH and whether their receptors are localized at the bleeding site.

METHODS

A prospective cohort consisted of 163 infants born before 32 weeks of gestation. Altogether 107 cord blood immunoproteins and 12 cytokines from peripheral blood obtained 1 and 7 days after birth were analyzed. Serial brain ultrasounds were assessed. Immunohistochemistry of a chemokine receptor from 14 autopsies was studied.

RESULTS

Low levels of cord chemokine CCL18 (chemokine (C-C motif) ligand 18) robustly predicted the risk of IVH grade II-IV when ante- and neonatal risk factors were considered. Cord CCL18 increased from 32 weeks to term. During the first week after very preterm birth CCL18 increased as the risk of new IVH cases decreased. CCL18 receptor, CCR3, was detectable in choroid plexus, periventricular capillary endothelium, ependymal cells, and in germinal matrix.

CONCLUSION

Low cord blood CCL18 is an independent risk factor of IVH. CCL18 may inhibit signal transduction of its receptor in periventricular cells. Defining the function and regulation of CCL18 may help to decrease the risk of IVH.

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.

Apparent diffusion coefficient on magnetic resonance imaging in pons and in corona radiata and relation with the neurophysiologic measurement and the outcome in very preterm infants

BACKGROUND

New imaging techniques allow a detailed visualization of the brain and the findings possibly correlate with neurophysiologic measurements and neurosensory and motor outcomes. Postnatal clinical factors known to associate with neurologic disabilities may contribute to brain abnormalities not visible to the naked eye.

OBJECTIVES

We evaluated whether quantitative measurement of organized water diffusion on MR imaging, apparent diffusion coefficient (ADC), relates to neurophysiologic function and to clinical risk factors and motor outcome in preterm infants.

METHODS

Diffusion-weighted imaging was successfully performed at term age on 30 infants born <32 weeks of gestation, birth weight <1,000 g. Infants with major destructive brain lesions were excluded from the final analysis (n = 2). ADC was calculated within regions of interest placed in pons and in white matter regions known to contain motor fibers. Brain stem auditory evoked potentials (BAEP) were registered at term age. Gross motor outcome was assessed using Griffiths Scales at 2 years of corrected age.

RESULTS

A positive correlation was found between ADC in the pons and the latency of wave III in BAEP (r = 0.619, p = 0.024). Need for inotrope support during the postnatal period and bronchopulmonary dysplasia associated with high ADC values in the pons and in the corona radiata. Infants with poor gross motor outcome had higher ADC in the corona radiata than infants with better outcome (mean = 1.343 vs. 1.197, p = 0.004).

CONCLUSIONS

This is the first study to report a relationship between ADC and BAEP measurements in the pons. The study may add to the current knowledge about the relation between postnatal clinical factors and diffusion-weighted imaging when evaluating the high-risk infants.

Severity of perinatal illness and cerebral cortical growth in preterm infants

AIM

We have shown previously that the degree of prematurity affects cortical surface area growth. We now addressed the question whether cortical surface area growth after preterm birth is predicted by the severity of peri- and postnatal illness.

METHODS

Cortical surface area was measured in 269 images from 111 infants born between 23 and 29 weeks and imaged at 23 to 48 weeks gestational age (GA). The severity of perinatal illness was assessed using the clinical risk index for babies score (CRIB I) and the severity of ongoing illness by the presence of chronic lung disease (CLD). The effects on cortical growth were modelled using generalized least-square regression for random effects with Bonferroni correction. To explore the results further we examined CRIB II, C-reactive protein (CRP) on the second day after birth, and time taken to achieve full enteral feeding.

RESULTS

Cortical surface area grew by 12.4% per week. Reduced cortical growth was predicted by adverse CRIB I (-0.15% per week per unit) and development of CLD (-1.18% per week). Secondary analysis showed that growth was related to adverse CRIB II (-0.36% per week per unit) and increasing CRP (-0.03% per week per mMol), but not by the time taken to achieve full enteral feeding.

CONCLUSION

After very premature birth illness severity predicts reduced cortical growth.

Blood cytokines during the perinatal period in very preterm infants: relationship of inflammatory response and bronchopulmonary dysplasia

OBJECTIVE

To evaluate the influence of chorioamnionitis (CA) on plasma cytokines and the cytokine-associated risk of bronchopulmonary dysplasia (BPD) during the perinatal period.

STUDY DESIGN

Eleven cytokines from 128 very low gestational age infants were analyzed from cord blood and from plasma at ages 1 day and 7 days after birth. The diagnosis of CA was based on histology of the placenta, fetal membranes, and umbilical cord. Neonatal risk factors were recorded.

RESULTS

In the 48 infants born with CA, high concentrations of inflammatory cytokines in cord blood decreased during the first postnatal day. Inflammatory cytokines in cord blood was associated with the severity of CA. At 1 day after birth, the concentration of interleukin (IL)-8 predicted the risk of BPD. For the 75 infants born without CA, cytokine concentrations increased after birth. For the 128 infants born with or without CA, at 1 day after birth, the concentrations of IL-8, granulocyte colony-stimulating factor, and anti-inflammatory IL-10 were associated with the risk of BPD, after adjustment for the duration of gestation and severity of respiratory distress during the first day.

CONCLUSIONS

In infants exposed to CA, insufficient inhibition of high fetal inflammatory cytokine response shortly after birth may increase the risk of BPD.

Population cohort associating chorioamnionitis, cord inflammatory cytokines and neurologic outcome in very preterm, extremely low birth weight infants

Intrauterine inflammation may relate to neurologic disability among preterm children. We investigated the relationship between chorioamnionitis, cord serum cytokines, and neurologic outcome. Sixty-one consecutively born very preterm extremely low birth weight (ELBW) infants were prospectively enrolled. Histologic inflammation in placenta and umbilical cord and vascular pathology were evaluated. Cord sera were analyzed for five proinflammatory cytokines. Serial brain ultrasound and magnetic resonance imaging were performed for evaluation of intraventricular hemorrhage (IVH grade I-III) and white matter damage (WMD: cystic periventricular leukomalacia or IVH grade IV). Neurologic and neurocognitive outcomes were assessed at the corrected age of 2 y. The incidences of HCA, WMD, and abnormal neurologic outcome were 48%, 13% and 19%, respectively. HCA or high IL-6 in cord serum predicted spontaneous preterm labor with high accuracy. HCA increased the risk of IVH grade II-III. In HCA, without either clinical chorioamnionitis or histologic placental perfusion defect, the children had a low risk of WMD (0%) and a low risk of abnormal neurologic outcome (6%). In HCA, the concentration of IL-6 in cord serum was lower in children with abnormal neurologic outcome than in children with normal neurologic outcome. In HCA and placental perfusion defect (compound defect) the risk of abnormal neurologic outcome was high. Compound placental defect and WMD additively predicted abnormal neurologic outcome. We propose that HCA together with other insults (placental perfusion defect or maternal systemic infection) increases the risk of poor neurologic outcome in very preterm ELBW infants.

Suboptimal neurodevelopment in very preterm infants is related to fetal cardiovascular compromise in placental insufficiency

OBJECTIVE

The purpose of this study was to determine the relationship between fetal cardiovascular hemodynamics and neurodevelopmental outcome in infants born before 32 gestational weeks with placental insufficiency.

STUDY DESIGN

Seventeen fetuses that underwent Doppler ultrasonography within 24 hours before delivery were included in this prospective cross-sectional study. Placental histology was examined. Multiple inflammatory markers and vascular endothelial growth factor (VEGF) and its receptor were analyzed from umbilical cord serum. Neurodevelopmental outcome was assessed by Griffiths scales at 1 year of corrected age.

RESULTS

Infants with suboptimal outcome (n = 7) had higher umbilical artery, ductus venosus, and inferior vena cava pulsatility index values (P < .05) and lower weight-indexed cardiac outputs (P < .05) than infants with normal outcome (n = 10). Placental histology and serum revealed no inflammation. VEGF values were similar among all infants.

CONCLUSION

In placental insufficiency with delivery before 32 gestational weeks, suboptimal neurodevelopment was related to decreased fetal weight-indexed cardiac output and increased systemic venous pressure.

Congenital subglottic stenosis in two unrelated pairs of siblings

Subglottic stenosis in infants is mostly acquired (secondary) and caused by granulation tissue or submucosal mucous gland hyperplasia after prolonged endotracheal intubation. Subglottic stenosis may also be congenital (primary), and it usually occurs sporadically. There are some reports of its association with inherited anomalies, but there are no previous reports of its familial occurrence in otherwise healthy children. This report describes two pairs of siblings referred for acute inspiratory stridor in whom subglottic stenosis was diagnosed by endoscopy. They were all born at term, and their parents were unrelated. One child had an anteriorly located anus but no other abnormalities.

CONCLUSION

Without any surgical intervention all had normal breathing at rest, but inspiratory stridor during respiratory infections and upon physical exercise at follow-up 4-9 y later.

Cerebral palsy is characterized by protein mediators in cord serum

Cerebral palsy (CP) is a major neurodevelopmental disability in childhood. An association between intrauterine infection and CP has been reported. We examined the relationship between inflammatory mediators in cord serum and CP in term and preterm children. Regional multicenter study was conducted on 19 CP children and 19 gestation-matched paired controls. CP children (n = 27) were further compared with controls of similar gestation at birth (n = 25). Serum levels of 78 protein mediators were analyzed. Eleven analytes correlated with the length of gestation both in cases and controls. In paired analysis, B-lymphocyte chemoattractant, ciliary neurotrophic factor, epidermal growth factor, interleukin (IL)-5, IL-12, IL-13, IL-15, macrophage migration inhibitory factor, monocyte chemoattractant protein-3, monokine induced by interferon gamma, and tumor necrosis factor-related apoptosis-inducing ligand were higher in children with CP (p < or = 0.05). Preterm infants with CP showed higher epidermal growth factor and lower levels of granulocyte-macrophage colony-stimulating factor, IL-2, macrophage-derived chemokine, and pulmonary and activation-regulated chemokine than their paired controls. Inflammatory mediators and growth factors serve as a footprint of the fetal response to an insult manifesting after birth as a permanent brain damage. The cytokine patterns at birth differ between premature and term infants who develop CP.