Medical, cognitive and academic outcomes of very low birth weight infants at age 10-14 years in Ireland

Effects of preterm birth and postnatal exposure to metal mixtures on neurodevelopment in children at 24 months of age

The effects of early-life metal exposure on neurodevelopment in very low birth weight preterm (VLBMP) children (with a birth weight of <1500 g and a gestational age of <37 weeks) have not been clearly established. We aimed to investigate associations of childhood exposure to multiple metals and preterm low birth weight with neurodevelopment among children at 24 months of corrected age. VLBWP children (n = 65) and normal birth weight term (NBWT) children (n = 87) were enrolled from Mackay Memorial Hospital in Taiwan between December 2011 and April 2015. Lead (Pb), cadmium (Cd), arsenic (As), methylmercury (MeHg), and selenium (Se) concentrations in the hair and fingernails were analyzed as biomarkers for metal exposure. The Bayley Scale of Infant and Toddler Development, Third Edition, was used to determine neurodevelopment levels. VLBWP children had significantly lower scores in all development domains compared to NBWT children. We also investigated preliminary exposure levels of VLBWP children to metals as reference values for future epidemiological and clinical survey. Fingernails are a useful biomarker for metal exposure to evaluate the effects on neurological development. A multivariable regression analysis revealed that fingernail Cd concentrations were significantly negatively associated with cognition (β = -0.63, 95% confidence interval (CI): -1.17 to -0.08) and receptive language function (β = -0.43, 95% CI: -0.82 to -0.04) among VLBWP children. VLBWP children with a 10-μg/g increase in the As concentration in their nails had a 8.67-point lower composite score in cognitive ability and a 1.82-point lower score in gross-motor functions. Effects of preterm birth and postnatal exposure to Cd and As were associated with poorer cognitive, receptive language, and gross-motor abilities. VLBWP children are at risk for neurodevelopmental impairments when exposed to metals. Further large-scale studies are needed assess to the risk of neurodevelopmental impairments when vulnerable children are exposed to metal mixtures.

Preterm Birth is Associated with Lower Academic Attainment at Age 12 Years: A Matched Cohort Study by Linkage of Population-Based Datasets

OBJECTIVE

To compare academic attainment at age 12 years in preterm children born below 30 weeks of gestation with matched term-born peers, using standardized, nationwide and well-validated school tests.

STUDY DESIGN

This population-based, national cohort study was performed by linking perinatal data from the nationwide Netherlands Perinatal Registry with educational outcome data from Statistics Netherlands and included 4677 surviving preterm children born at 25^0/7-29^6/7 weeks of gestational age and 366 561 controls born at 40 weeks of gestational age in 2000-2007. First, special education participation rate was calculated. Subsequently, all preterm children with academic attainment test data derived at age 12 years were matched to term-born children using year and month of birth, sex, parity, socioeconomic status, and maternal age. Total, language, and mathematics test scores and secondary school level advice were compared between these 2 groups.

RESULTS

Children below 30 weeks of gestation had a higher special education participation rate (10.2% vs 2.7%, P < .001) than term-born peers. Preterm children had lower total (-0.37 SD; 95% CI -0.42 to -0.31), language (-0.21 SD; 95% CI -0.27 to -0.15), and mathematics (-0.45 SD; 95%CI -0.51 to -0.38) z scores, and more often a prevocational secondary school level advice (62% vs 46%, P < .001).

CONCLUSIONS

A substantial proportion of children born before 30 weeks of gestation need special education at the end of elementary schooling. These children have significant deficits on all measures of academic attainment at age 12 years, especially mathematics, compared with matched term-born peers.

Low Birth Weight and Psychoeducational Outcomes: Investigation of an African American Birth Cohort

African Americans experience more than double the prevalence of low birth weight (LBW)/premature birth compared to their Caucasian counterparts, reflecting a public health crisis and a significant social justice concern. However, there is a paucity of LBW outcome studies in African American samples. There are even fewer that investigate developmental outcomes within the moderately LBW range (i.e., 1500–2500 g), the most prevalent category of LBW births. This study investigates the relationship between LBW and various psychoeducational outcomes in a prospectively designed African American birth cohort. Multivariate logit analyses of the Johns Hopkins University Pathways to Adulthood study compared LBW children with normal birth weight children on a number of outcome measures at seven and 8 years of age. Results revealed that children born within the lowest birth weight category produced the most adverse findings, from both a statistical and clinical standpoint, on measures of cognitive ability, academic achievement, speech, language, auditory processing, and visual–motor integration.

Timing of Referral to Early Intervention Services in Infants With Severe Bronchopulmonary Dysplasia

This study is a secondary analysis of an observational prospective case series of 50 infants with severe bronchopulmonary dysplasia that describes patient factors associated with the time between initial hospital discharge and referral to early intervention (EI) services. It also evaluates associations between (1) timing of EI referral and reception of EI services and (2) early referral to EI and developmental outcomes at 18 to 36 months corrected age. The results demonstrated that a referral from a neonatologist versus a pediatrician was associated with fewer days between discharge and EI referral. Earlier EI referrals were associated with a shorter time to intake evaluation and service initiation. The Bayley-III (Bayley Scales of Infant and Toddler Development, 3rd Edition) scores at 24 months corrected age (n = 28) were not associated with timing of EI referral. In conclusion, an early referral to EI promoted earlier evaluation and initiation of EI services and should be standard for high-risk infants.

Educational and health outcomes associated with bronchopulmonary dysplasia in 15-year-olds born preterm

Introduction

To evaluate the consequences of bronchopulmonary dysplasia (BPD) on academic outcomes and healthcare use in adolescents born very preterm.

Methods

This cohort study included 15-year-old adolescents born very preterm (< 32 weeks) between 2011 and 2013, with and without BPD, and controls born full term. Data regarding academic performance, current medical follow-up, and family characteristics were collected. Multivariate logistic regression was used to quantify relationships between academic outcomes and BPD.

Results

From the 1341 children included in the initial cohort, 985 adolescents were eligible and 351 included (55 preterms with a history of BPD, 249 without, and 47 controls). Among adolescents born very preterm, a history of BPD was associated with a higher risk to attend a school for children with special needs (p < 0.05) and to have repeated a grade (p = 0.01). It was also associated with an increased number of medical and paramedical consultations. A history of BPD was not associated with the parents’ employment status, family structure, or the presence of younger siblings.

Conclusion

This study highlights that a history of BPD is associated with poorer academic outcomes and high healthcare use in adolescence.

Investigating the relationship between fetal growth and academic attainment: secondary analysis of the Born in Bradford (BiB) cohort

Background

The relationship between ultrasongraphically derived estimates of fetal growth and educational attainment in the postnatal period is unknown. Results from previous studies focusing on cognitive ability, however, suggest there may be gestation-specific associations. Our objective was to model growth in fetal weight (EFW) and head circumference (HC) and identify whether growth variation in different periods was related to academic attainment in middle childhood.

Methods

Data come from the Born in Bradford (BiB) cohort study, which has performed data linkage to both routine antenatal scans and national academic attainment tests at age 6-7 years. Multilevel linear spline models were used to model EFW and HC. Random effects from these were related to Key Stage 1 (KS1) results in reading, writing, mathematics, science and a composite of all four (age 6-7 years), using ordinal logistic and logistic regression. Associations were adjusted for potential confounders, facilitated by directed acyclic graphs. Missing covariate data were imputed using multiple imputation.

Results

In all, 6995 and 8438 children had complete KS1, and EFW and HC data, respectively. Positive associations were observed between both fetal weight in early pregnancy (14 weeks) and EFW growth in mid-pregnancy (14-26 weeks) and the individual KS1 outcomes. Furthermore, after adjustment for previous size and confounders, a 1-z score increase in growth in mid-pregnancy was associated with an 8% increased odds of achieving the expected standard for all KS1 outcomes [odds ratio (OR): 1.08, 95% confidence interval (CI): 1.02; 1.13]. Similar results were observed for HC, with generally larger effect sizes. Smaller associations were observed with growth in the early-third trimester, with no associations observed with growth in the later-third trimester.

Conclusions

We observed consistent positive associations between fetal size and growth in early and mid-gestation and academic attainment in childhood. The smaller and null associations with growth in the early-third and later-third trimester, respectively, suggests that early-mid gestation may be a sensitive period for future cognitive development.

Preliminary study of urinary arsenic concentration and arsenic methylation capacity effects on neurodevelopment in very low birth weight preterm children under 24 months of corrected age

The neurological prognoses of very low birth weight preterm (VLBWP) children during the first 2 years of life will influence their neurodevelopment during subsequent childhood years and adolescence. The objective of this study was to systemic investigate relationships of urinary arsenic (As) concentrations, the As methylation capability, and toenail As concentrations on cognitive, language, and motor development in VLBWP children under 24 months of corrected age.Participants (n = 60) in our study were recruited from October 2010 to April 2013. Urine and toenail samples were collected for evaluation to assess As exposure. The Bayley scales of infant development III were used to evaluate neurodevelopment at 2 years of corrected age. Concentrations of As species in urine and the As concentration in toenails were, respectively, analyzed using HPLC-HG-AAS and ICP-MS.The mean concentration of total As was 28.6 μg/g creatinine, and inorganic As was 1.01 μg/L in urine. The urine contained an average of 3% inorganic As, 2% monomethylarsonic acid, and 95% dimethylarsinic acid (DMA). The mean concentration of As in toenails was 225 ng/g. Children with a longer gestational age (≥28 weeks) and higher DMA % levels appeared to have the highest unadjusted cognitive and fine motor scores.Our study results suggest that gestational age is associated with neurodevelopment in VLBWP children. We recommend that further study simultaneously analyze multiple environmental contaminants that may have adverse effects on neurodevelopment, use biomarkers for the mother-child pair, and determine whether prenatal or postnatal As exposure has a greater influence on the neurological development of VLBWP children.

Academic performance of children born preterm: a meta-analysis and meta-regression

BACKGROUND

Advances in neonatal healthcare have resulted in decreased mortality after preterm birth but have not led to parallel decreases in morbidity. Academic performance provides insight in the outcomes and specific difficulties and needs of preterm children.

OBJECTIVE

To study academic performance in preterm children born in the antenatal steroids and surfactant era and possible moderating effects of perinatal and demographic factors.

DESIGN

PubMed, Web of Science and PsycINFO were searched for peer-reviewed articles. Cohort studies with a full-term control group reporting standardised academic performance scores of preterm children (<37 weeks of gestation) at age 5 years or older and born in the antenatal steroids and surfactant era were included. Academic test scores and special educational needs of preterm and full-term children were analysed using random effects meta-analysis. Random effects meta-regressions were performed to explore the predictive role of perinatal and demographic factors for between-study variance in effect sizes.

RESULTS

The 17 eligible studies included 2390 preterm children and 1549 controls. Preterm children scored 0.71 SD below full-term peers on arithmetic (p<0.001), 0.44 and 0.52 SD lower on reading and spelling (p<0.001) and were 2.85 times more likely to receive special educational assistance (95% CI 2.12 to 3.84, p<0.001). Bronchopulmonarydysplasia explained 44% of the variance in academic performance (p=0.006).

CONCLUSION

Preterm children born in the antenatal steroids and surfactant era show considerable academic difficulties. Preterm children with bronchopulmonarydysplasia are at particular risk for poor academic outcome.

A gradient relationship between low birth weight and IQ: A meta-analysis

Multiple studies have reported that individuals with low birth weights (LBW, <2500 g) have a lower intelligence quotient (IQ) than those with normal birth weights (NBW, ≥2500 g). Based on 57 eligible individual studies including 12,137 participants, we performed a meta-analysis to estimate the association between low birth weight and individuals' IQ scores (IQs). The pooled weight mean difference (WMD) in IQs between NBW and LBW individuals was 10 (95% CI 9.26-11.68). The WMD was stable regardless of age. No publication bias was detected. The mean IQs of the extremely low birth weight (ELBW, <1000 g), very low birth weight (VLBW, 1000-1499 g), moderately low birth weight (MLBW, 1500-2499 g) and NBW individuals were 91, 94, 99 and 104, respectively. Additionally, the WMD in IQs with NBW were 14, 10 and 7 for ELBW, VLBW, and MLBW individuals, respectively. Two studies permitted estimates of the influence of social determinants of health to the discrepancy in IQs, which was 13%. Since IQ is inherited and influenced by environmental factors, parental IQs and other factors contribute to residual confounding of the results. As the conclusion was based on population studies, it may not be applicable to a single individual.

Factors affecting the cognitive profile of 11-year-old children born very preterm

BackgroundPreterm birth is a risk for cognitive development. This study assessed the cognitive profile of children born very preterm at the age of 11 years as well as the associated risk factors.MethodsA total of 128 children born very preterm were included. Magnetic resonance imaging was performed at term age. Cognitive development was assessed using the full-scale intelligence quotient (IQ) and four domains of the Wechsler Intelligence Scale for Children, fourth edition (WISC-IV), Finnish translation. The results were compared with test norms.ResultsMost study children performed at average (51%) or low average (21%) levels in the full-scale IQ assessment. The correlation between 5- and 11-year full-scale IQ was 0.73 (P<0.001). Compared with the normative data, children born very preterm performed poorer in all domains of the cognitive profile. The only significant risk factor for poor general cognition was major brain pathology. When considering all four domains of WISC-IV, low paternal education, male gender, and low birth weight z score were also found to be significant risk factors.ConclusionsLess than one-third of the children born very preterm performed below the low average cognitive level at 11 years of age. Specific neonatal and sociodemographic risk factors were identified as affecting the cognitive profile.

Mental health outcomes at age 11 of very low birth weight infants in Ireland

Aim To compare mental health (MH) outcomes of and service use by children born under 1500 g in Ireland with a matched control group.

METHOD

Using a retrospective cohort design, semi-structured and standardised MH assessments were conducted with parents, teachers and youth.

RESULTS

A total of 64 of 127 surviving children from a very low birth weight (VLBW) cohort from a National Maternity Hospital participated at a mean age of 11.6 years (s.d. 1.0), along with 51 matched controls. More VLBW children received clinical or borderline scores when rated by parents [χ 2 (1, n=114)=7.3, p=0.007] or youths [χ 2 (1, n=114)=4.83, p=0.028], but not by teachers [χ 2 (1, n=114)=1.243, p=0.463]. There was no increase in the use of MH services. A main effect of birth weight remained on the parent Strengths and Difficulties Questionnaire [F (1, 88)=5.07, p<0.05) after controlling for intelligence quotient (IQ) and socio-economic status (SES), but only on hyperactivity in males. SES, rather than IQ or birth weight, predicted identification of problems by teachers [F (1, 82)=6.99, p=0.01). Interpretations Teachers miss MH difficulties and are influenced more by SES than by IQ or birth weight. This has implications for MH service access. Initial perinatal investment needs to be matched with ongoing surveillance and psychoeducation to ensure that disorders are recognised early and offered appropriate interventions.

Reading abilities in school-aged preterm children: a review and meta-analysis

AIM

Children born preterm (at ≤32wks) are at risk of developing deficits in reading ability. This meta-analysis aims to determine whether or not school-aged preterm children perform worse than those born at term in single-word reading (decoding) and reading comprehension.

METHOD

Electronic databases were searched for studies published between 2000 and 2013, which assessed decoding or reading comprehension performance in English-speaking preterm and term-born children aged between 6 years and 13 years, and born after 1990. Standardized mean differences in decoding and reading comprehension scores were calculated.

RESULTS

Nine studies were suitable for analysis of decoding, and five for analysis of reading comprehension. Random-effects meta-analyses showed that children born preterm had significantly lower scores (reported as Cohen's d values [d] with 95% confidence intervals [CIs]) than those born at term for decoding (d=-0.42, 95% CI -0.57 to -0.27, p<0.001) and reading comprehension (d=-0.57, 95% CI -0.68 to -0.46, p<0.001). Meta-regressions showed that lower gestational age was associated with larger differences in decoding (Q[1]=5.92, p=0.02) and reading comprehension (Q[1]=4.69, p=0.03) between preterm and term groups. Differences between groups increased with age for reading comprehension (Q[1]=5.10, p=0.02) and, although not significant, there was also a trend for increased group differences for decoding (Q[1]=3.44, p=0.06).

INTERPRETATION

Preterm children perform worse than peers born at term on decoding and reading comprehension. These findings suggest that preterm children should receive more ongoing monitoring for reading difficulties throughout their education.