Academic achievement of low birthweight children at age 11: the role of cognitive abilities at school entry

Impact of low birth weight on academic attainment during adolescence: A comprehensive retrospective cohort study using linked data

BACKGROUND

This study addresses a critical knowledge gap by exploring the intricate relationship between low birth weight (LBW) and the heightened risk of suboptimal academic achievement during adolescence through a comprehensive retrospective cohort design.

METHODS

In this registry-based cohort study, meticulously linked health and curriculum-based test data for individuals born in New South Wales (NSW), Australia, between 2003 and 2005 were employed. Birth weight data were carefully sourced from the NSW perinatal data collection (PDC). The educational performance of offspring was thoroughly evaluated using the National Assessment Program for Literacy and Numeracy (NAPLAN) during grade 9, approximately at 14 years of age.

RESULTS

After rigorous adjustments for potential confounders, findings revealed a compelling narrative: LBW adolescents demonstrated an elevated susceptibility to not meeting national minimum standards across all domains, encompassing spelling [OR, 1.59 (95%CI 1.48-1.69)], writing [OR, 1.51 (95%CI 1.41-1.61)], reading [OR, 1.38 (95%CI 1.29-1.48)], and numeracy [OR, 1.52 (95%CI 1.40-1.63)]. Notably, LBW boys exhibited a more pronounced inclination towards diminished academic performance compared to their female counterparts.

CONCLUSIONS

This comprehensive retrospective cohort study, based on linked data, unequivocally establishes LBW as significantly associated with an increased vulnerability to substandard educational achievement during adolescence. Particularly robust effects were observed in females across all outcomes. Aimed at investigating whether LBW serves as a predictive factor for later academic difficulties, this study underscores the imperative for the adoption and fortification of preventative and early intervention strategies to curtail the prevalence of LBW-associated academic underachievement in later adolescence.

Immigrant ancestry and birthweight across two generations born in Sweden: an intergenerational cohort study

INTRODUCTION

Differences in birthweight are often seen between migrants and natives. However, whether migrant-native birthweight inequalities widen, narrow or remain persistent across generations when comparing the descendants of immigrants and natives remains understudied. We examined inequalities in birthweight of mothers (G2) and daughters (G3) of foreign-born grandmothers (G1) compared with those of Swedish-born grandmothers.

METHODS

We used population registers with multigenerational linkages to identify 314 415 daughters born in Sweden during the period 1989-2012 (G3), linked to 246 642 mothers (G2) born in Sweden during 1973-1996, and to their grandmothers (G1) who were Swedish or foreign-born. We classified migrants into non-western, Eastern European, the rest of Nordic and Western. We used multivariable methods to examine mean birthweight and low birthweight (<2500 g; LBW).

RESULTS

Birthweight between individuals with Swedish background (G1) and non-western groups increased from -80 g to -147 g between G2 (mothers) and G3 (daughters), respectively. Furthermore, the odds of LBW increased among the G3 non-western immigrants compared with those with Swedish grandmothers (OR: 1.38, 95% CI 1.12 to 1.69). Birthweight increased in both descendants of Swedes and non-western immigrants, but less so in the latter (83 g vs 16 g).

CONCLUSION

We observed an increase in birthweight inequalities across generations between descendants of non-western immigrants and descendants of Swedes. This finding is puzzling considering Sweden has been lauded for its humanitarian approach to migration, for being one of the most egalitarian countries in the world and providing universal access to healthcare and education.

Reading and spelling skills of prematurely born children in light of the underlying cognitive factors

Prematurity is a serious risk factor for learning difficulties. Within the academic skills reading has the greatest impact on the prospects of the students; therefore, studying the reading skills in the risk populations is very important. The aim of our study was to investigate reading and spelling skills of prematurely born children. Our target group consisted of 8-11-year-old children (n = 23) who were born preterm with very low birthweights (VLBW). For comparison 57 full-term children (27 good readers and 30 dyslexics) were included in the study sample. To assess the reading and spelling abilities the Hungarian version of the 3DM (Dyslexia Differential Diagnosis) was used. Cognitive abilities were tested using the Hungarian adaptation of the WISC-IV and the Rey Complex Figure Test. The data were analyzed with a novel statistical approach using the R program. In the cognitive measures the mean performances of all three groups fell within the normal range. In the WISC-IV Full-scale IQ as well as in some other cognitive measures the good readers significantly outperformed both the dyslexics and the preterms. The findings of the study did not confirm our expectation that VLBW prematurity should lead to developmental disadvantages in the acquisition of reading and spelling skills since in the reading and spelling performances of the good readers and the preterms did not differ, while both the good readers and the preterms scored higher than the dyslexics. The results suggest that the cognitive assets of the preterm children contributing to their reading and spelling performances were their good spatial-visual memory, working memory, and processing speed. The identification of the cognitive mechanisms underlying reading and spelling abilities is of crucial importance for designing intervention for children with deficits in these academic skills.

A Population-Based Study of School Readiness Determinants in a Large Urban Public School District

Objectives We examined biologic and social determinants of school readiness in an urban population and whether childcare altered these associations. Methods A retrospective cohort study was conducted using school readiness data linked to birth certificates of first-time kindergarten students (n = 39,463) in a large, urban public-school district during 2002-2012. Multivariate linear regression models compared mean readiness scores (MRS) for students born low birthweight (LBW) or preterm (PTB) and by childcare type, adjusting for other student and parent risk factors. Results MRSs for moderately LBW (1000-2499 g), extremely LBW (< 1000 g), moderately PTB (28-36 weeks), early-term (37-38 weeks) and post-term (42 + weeks) students were significantly lower than scores for their normal weight or full-term peers, adjusting for childcare type and other student and parent characteristics. Childcare was an important predictor of MRSs. MRSs were highest for district prekindergarten (PK) students and for students of mothers with greater years of education. Conclusions for Practice Social and biologic differences in MRSs for children entering school in a large urban public-school district suggest the need for greater attention to family and child health backgrounds. Increased enrollment in formal childcare may improve school readiness in these settings.

Effects of extreme prematurity and kindergarten neuropsychological skills on early academic progress

OBJECTIVE

The study was designed to investigate the effect of extreme prematurity on growth in academic achievement across the early school years and the validity of kindergarten neuropsychological skills as predictors of achievement.

METHOD

A 2001-2003 birth cohort of 145 extremely preterm/extremely low birth weight (EPT/ELBW) children from a single medical center, along with 111 normal birth weight (NBW) classmate controls, were recruited during their first year in kindergarten and followed annually across the next 2 years in school. Mixed model analysis was conducted to compare the groups on growth in achievement across years and examine kindergarten neuropsychological skills as predictors of growth.

RESULTS

The EPT/ELBW group scored significantly below NBW controls on all achievement tests across years and had higher rates of special education placement and grade repetition. Despite limited catch-up of the EPT/ELBW group to the NBW controls in spelling, group differences were generally stable. Differences in spelling and mathematics achievement remained significant when controlling for global intelligence or excluding children who had intellectual or neurosensory impairments or repeated a grade. Higher scores on kindergarten tests of multiple neuropsychological ability domains predicted higher achievement levels and steeper growth in achievement.

CONCLUSIONS

The findings document persistent academic weaknesses in EPT/ELBW children across the early school years. Results point to the need for preschool interventions to enhance academic readiness and suggest that neuropsychological skills assessed in kindergarten are useful in identifying individual differences in early learning progress. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Effect of prematurity and low birth weight in visual abilities and school performance

BACKGROUND

Prematurity and low birth weight are known risk factors for cognitive and developmental impairments, and school failure. Visual perceptual and visual motor skills seem to be among the most affected cognitive domains in these children.

AIMS

To assess the influence of prematurity and low birth weight in visual cognitive skills and school performance.

METHODS

We performed a prospective cohort study, which included 80 boys and girls in an age range from 5 to 13. Subjects were grouped by gestational age at birth (preterm, <37 weeks; term, 37-42 weeks) and birth weight (small for gestational age (SGA), <10th centile; appropriate weight for gestational age (AGA), ≥10th centile). Each child underwent full ophthalmologic assessment and standardized testing of visual cognitive abilities (Test of Visual Perceptual Skills and Test of Visual Analysis Skills). Parents completed a questionnaire on school performance in children.

RESULTS

Figure-ground skill and visual motor integration were significantly decreased in the preterm birth group, compared with term control subjects (figure-ground: 45.7 vs 66.5, p=0.012; visual motor integration, TVAS: (9.9 vs 11.8, p=0.018), while outcomes of visual memory (29.0 vs 47.7, p=0.012), form constancy (33.3 vs 52.8, p=0.019), figure-ground (37.4 vs 65.6, p=0.001), and visual closure (43.7 vs 62.6 p=0.016) testing were lower in the SGA (vs AGA) group. Visual cognitive difficulties corresponded with worse performance in mathematics (r=0.414, p=0.004) and reading (r=0.343, p=0.018).

CONCLUSION

Specific patterns of visual perceptual and visual motor deficits are displayed by children born preterm or SGA, which hinder mathematics and reading performance.

Mid-Childhood Outcomes of Repeat Antenatal Corticosteroids: A Randomized Controlled Trial

OBJECTIVE

To assess if exposure to repeat dose(s) of antenatal corticosteroids has beneficial effects on neurodevelopment and general health in mid-childhood, at 6 to 8 years' corrected age.

METHODS

Women at risk for very preterm birth, who had received a course of corticosteroids ≥7 days previously, were randomized to intramuscular betamethasone (11.4 mg Celestone Chronodose) or saline placebo, repeated weekly if risk of very preterm birth remained. Mid-childhood assessments included neurocognitive function, behavior, growth, lung function, blood pressure, health-related quality of life, and health service utilization. The primary outcome was survival free of neurosensory disability.

RESULTS

Of the 1059 eligible long-term survivors, 963 (91%) were included in the primary outcome; 479 (91%) in the repeat corticosteroid group and 484 (91%) in the placebo group. The rate of survival free of neurosensory disability was similar in both groups (78.3% repeat versus 77.3% placebo; risk ratio 1.00, 95% confidence interval, 0.94-1.08). Neurodevelopment, including cognitive function, and behavior, body size, blood pressure, spirometry, and health-related quality of life were similar in both groups, as was the use of health services.

CONCLUSIONS

Treatment with repeat dose(s) of antenatal corticosteroids was associated with neither benefit nor harm in mid-childhood. Our finding of long-term safety supports the use of repeat dose(s) of antenatal corticosteroids, in view of the related neonatal benefits. For women at risk for preterm birth before 32 weeks' gestation, ≥7 days after an initial course of antenatal corticosteroids, clinicians could consider using a single injection of betamethasone, repeated weekly if risk remains.

Usefulness of the most popular neurodevelopmental tests in preschool assessment of children born with very low birth weight

BACKGROUND

The aim of our study was multifaceted neurodevelopmental examination of children born prematurely with very low birth weight (VLBW) in order to evaluate the usefulness of popularly used tests. The second aim of the study was exploration of risk and protective factors of neurodevelopmental impairment.

METHODS

Eighty-nine VLBW patients were evaluated at the age of 50 months. All children underwent anthropometric measurements and psychomotor tests: functional independence measure scale (WeeFIM), Gross Motor Function Measurement (GMFM), non-verbal psychometric evaluation (Leiter test), Developmental Test of Visual Perception (DTVP-2), temperament questionnaire (EAS-C) and children vocabulary test (TSD).

RESULTS

Most severe deficits in ex-preterms' neurodevelopment were associated with verbal abilities, visual perception and temper abnormalities. WeeFIM, DTVP-2, Leiter and vocabulary tests' results correlated with each other. The lowest percent of children with deficits in WeeFIM test indicates, that it seems to be the most valuable tool for identification of the most seriously impaired children. Due to the highest percent of children with visual perception deficits, DTVP test seems to be good second choice in assessment of children born prematurely. In motor assessment GMFM appears to be more adequate than cerebral palsy (CP) diagnosis. Almost one fifth of VLBW did not reach 85% in Gross Motor Function Measurement, although only 9% of children had CP.

CONCLUSIONS

Children born with VLBW had deficits in every part of psychometric evaluation. We believe that the most useful tests in assessment VLBW patients are WeeFIM, GMFM and DTVP. Children with severe prematurity complications could require more precise evaluation.

Unconditional Prenatal Income Supplement and Birth Outcomes

BACKGROUND AND OBJECTIVES

Perinatal outcomes have improved in developed countries but remain poor for disadvantaged populations. We examined whether an unconditional income supplement to low-income pregnant women was associated with improved birth outcomes.

METHODS

This study included all mother-newborn pairs (2003-2010) in Manitoba, Canada, where the mother received prenatal social assistance, the infant was born in the hospital, and the pair had a risk screen (N = 14 591). Low-income women who received the income supplement (Healthy Baby Prenatal Benefit [HBPB], n = 10 738) were compared with low-income women who did not receive HBPB (n = 3853) on the following factors: low birth weight, preterm, small and large for gestational age, Apgar score, breastfeeding initiation, neonatal readmission, and newborn hospital length of stay (LOS). Covariates from risk screens were used to develop propensity scores and to balance differences between groups in regression models; γ sensitivity analyses were conducted to assess sensitivity to unmeasured confounding. Population-attributable and preventable fractions were calculated.

RESULTS

HBPB was associated with reductions in low birth weight (aRR, 0.71 [95% CI, 0.63-0.81]), preterm births (aRR, 0.76 [95% CI, 0.69-0.84]) and small for gestational age births (aRR, 0.90 [95% CI, 0.81-0.99]) and increases in breastfeeding (aRR, 1.06 [95% CI, 1.03-1.09]) and large for gestational age births (aRR, 1.13 [95% CI, 1.05-1.23]). For vaginal births, HBPB was associated with shortened LOS (weighted mean, 2.86; P < .0001). Results for breastfeeding, low birth weight, preterm birth, and LOS were robust to unmeasured confounding. Reductions of 21% (95% CI, 13.6-28.3) for low birth weight births and 17.5% (95% CI, 11.2-23.8) for preterm births were associated with HBPB.

CONCLUSIONS

Receipt of an unconditional prenatal income supplement was associated with positive outcomes. Placing conditions on income supplements may not be necessary to promote prenatal and perinatal health.

Birth characteristics and all-cause mortality: a sibling analysis using the Uppsala birth cohort multigenerational study

This paper investigates the association between perinatal health and all-cause mortality for specific age intervals, assessing the contribution of maternal socioeconomic characteristics and the presence of maternal-level confounding. Our study is based on a cohort of 12,564 singletons born between 1915 and 1929 at the Uppsala University Hospital. We fitted Cox regression models to estimate age-varying hazard ratios of all-cause mortality for absolute and relative birth weight and for gestational age. We found that associations with mortality vary by age and according to the measure under scrutiny, with effects being concentrated in infancy, childhood or early adult life. For example, the effect of low birth weight was greatest in the first year of life and then continued up to 44 years of age (HR between 2.82 and 1.51). These associations were confirmed in within-family analyses, which provided no evidence of residual confounding by maternal characteristics. Our findings support the interpretation that policies oriented towards improving population health should invest in birth outcomes and hence in maternal health.

Evidence of a Gene × Environment Interaction Between Birth Weight and Genetic Risk in the Prediction of Criminogenic Outcomes Among Adolescent Males

A number of studies have revealed that low birth weight children have a heightened risk of various maladaptive outcomes, including academic challenges and delinquent involvement. However, very little research to date has examined whether the relationship between low birth weight, poor academic performance, and delinquent peer affiliation is moderated by genetic risk. Using data from the National Longitudinal study of Adolescent Health, the present study examines whether male adolescents born at very low birth weights are significantly predisposed to poor academic performance and delinquent peer affiliation. Moreover, we test whether the effect of birth weight on these outcomes is conditioned by level of genetic risk. We find no evidence that very low birth weight males are more likely to affiliate with delinquent peers or perform poorly in school during adolescence. However, upon examining gene-environment interactions, we find that being born at a very low birth weight does significantly increase the odds of poor academic performance and delinquent peer affiliation among males who possess a higher level of genetic risk. Limitations are noted and the implications of the findings are discussed.

Reading deficits in very low birthweight children are associated with vocabulary and attention issues at the age of seven

Aim

This Swedish study compared reading skills between seven‐year‐old children with a very low birthweight (VLBW) and controls with a normal birthweight, exploring associations between reading variables and cognition, parent‐rated behaviour, perinatal factors and family factors.

Methods

We studied 51 VLBW children, with no major neurodevelopmental impairments and attending their first year at a regular school, and compared them with the 51 sex‐ and age‐matched controls. The test battery, carried out at 7.8 ± 0.4 years of age, included reading skills, the Wechsler Intelligence Scale for Children – III and the Child Behaviour Checklist.

Results

Very low birthweight children with a mean birthweight of 1105 g (±291 g) and a gestational age of 28.8 (±2.2) weeks scored significantly lower in all reading subtests and cognition and demonstrated more behavioural problems than normal birthweight controls. We also found significant associations between poor vocabulary, combined with attention problems, and phonological awareness, rapid naming and spelling control. Perinatal factors had no association with reading function, and socio‐economic factors had very few.

Conclusion

Very low birthweight children demonstrated deficits in all reading domains and had poorer cognition and more behavioural problems at the age of seven, with reading ability related to vocabulary and attention.

Timeliness, frequency and content of antenatal care: which is most important to reducing indigenous disparities in birth weight in Mexico?

This article examines the role of components of adequate antenatal care (ANC) in disparities in birth weight between indigenous and non-indigenous women in Mexico. We estimate the potential for added weight gain among indigenous infants if their mothers received timely, frequent ( ≥4 visits) and complete ANC (≥75% of recommended processes of care). We used population-based survey data (2012;N= 6612 women 12-49). We applied quantile regression to examine heterogeneity of the association between adequate ANC, indigenous ethnicity and birth weight across quantiles of the birth weight distribution. A greater proportion of indigenous women reported a low-birth weight infant (<2.5 kg) at last delivery (14 vs 8% among non-indigenous women). Coverage of adequate ANC (timely, frequent and complete care) is lower among indigenous (59%, CI:53;65) than non-indigenous (68%, CI:66;70) women. Indigenous ethnicity is associated with a lower birth weight across quantiles of the observed birth weight distribution: between 300 g in the 0.05, 0.10 and 0.25 quantiles. Among indigenous women, greater newborn weight gains are achieved in the lowest quantiles if they have access to ≥75% of the content of ANC compared with those that did not have access: ∼180 and 260 g are gained in both quantiles 0.05 and 0.10, respectively. This means that the smallest indigenous newborns could potentially reach 2.36 kg (from 1.86 kg), close to the normal weight threshold. The frequency of ANC was positively associated with birth weight for all women but complete ANC appears to differentially affect indigenous women at the bottom of the birth weight distribution. The marginal gains obtained among indigenous newborns that received complete ANC compared with indigenous/non-indigenous newborns did not receive it, is particularly important in low-birth weight quantiles. Delivering basic processes of ANC may therefore have the potential to impact the highest risk women and help them to overcome the low-birth weight threshold.

Relationship of weight status, physical activity and screen time with academic achievement in adolescents

OBJECTIVE

The aim of this study was to examine the relationship of weight status, physical activity and screen time with academic achievement in Chilean adolescents.

METHODS

The present cross-sectional study included 395 adolescents. The International Obesity Task Force cut-off points were used to define the weight status. Physical activity was assessed using the Physical Activity Questionnaire for Adolescents and screen time was assessed using several questions about television, videogame and computer use. Academic achievement was measured using the mean of the grades obtained in mathematics and language subjects.

RESULTS

In both genders, adolescents with obesity and excessive screen time earned worse grades compared to their non-obese peers and their peers that complied with screen time recommendations. The logistic regression analysis showed that adolescents with obesity, classified with medium-low physical activity and excessive screen time recommendations (excess ≥2h/day) are less likely to obtain high academic achievement (boys: OR=0.26; girls: OR=0.23) compared to their non-obese peers, high levels of physical activity and those who comply with the current screen time recommendations. Similar results were observed in adolescents with obesity and classified with medium-low physical activity (boys: OR=0.46; girls: OR=0.33) or excessive screen time (boys: OR=0.35; girls: OR=0.36) compared to adolescents with high levels of physical activity and those who complied with the screen time recommendations, respectively.

CONCLUSION

This study shows that when combined, obesity, low-medium levels of physical activity and excessive screen time might be related to poor academic achievement.

Perinatal, neonatal, and family social factors predicting poor school outcome of low-birth-weight survivors: an integrative review

PURPOSE

To examine the relationship of perinatal factors, neonatal factors, and family characteristics with school outcomes of low-birth-weight (LBW) children.

DESIGN AND METHODS

An integrative review of the literature was performed using electronic databases focusing on key words, including school outcome, school performance, educational outcome, academic outcome/academic achievement, and LBW.

RESULTS

The in utero or neonatal risk factors for poor school outcome included in this review were perinatal brain injury, brain structural abnormality, motor deficits, and neonatal conditions. Social risk factors found to contribute to poorer school outcomes were family structure, family stability, parental education, poverty, male sex, nonwhite race, and acculturation level.

CONCLUSIONS

Long-term school outcomes of LBW children are influenced by a number of factors related to the characteristics of both children and their families. These factors need to be considered when designing preventive interventions.

Objectively measured physical activity has a negative but weak association with academic performance in children and adolescents

AIM

There is an emerging body of evidence on the potential effects of regular physical activity on academic performance. The aim of this study was to add to the debate, by examining the association between objectively measured physical activity and academic performance in a relatively large sample of children and adolescents.

METHODS

The Spanish UP & DOWN study is a 3-year longitudinal study designed to assess the impact, overtime, of physical activity and sedentary behaviours on health indicators. This present analysis was conducted with 1778 children and adolescents aged 6-18 years. Physical activity was objectively measured by accelerometry. Academic performance was assessed using school grades.

RESULTS

Physical activity was inversely associated with all academic performance indicators after adjustment for potential confounders, including neonatal variables, fatness and fitness (all p < 0.05). This association became nonsignificant among quartiles of physical activity. There were only slight differences in academic performance between the lowest and the second quartile of physical activity, compared to the highest quartile, with very small effect size (d < 0.20).

CONCLUSION

Objectively measured physical activity may influence academic performance during both childhood and adolescence, but this association was negative and very weak. Longitudinal and intervention studies are necessary to further our understanding.

Birth weight and academic achievement in childhood

Research has shown that birth weight has a lasting impact on later-life outcomes such as educational attainment and earnings. This paper examines the role of health at birth in determining academic achievement in childhood, which may provide the link between birth weight and adult outcomes. Using three waves of the Child Development Supplement of the Panel Study of Income Dynamics data over 1997-2007, we build on the literature by employing the fetal growth rate as a proxy for net nutritional intake in utero and propose a nested error-component two-stage least squares estimator that draws on internal instruments from alternative dimensions of the multilevel panel data set. In particular, this alternative estimator allows us to exploit the information on children with no siblings in the sample, which comprise over 40% of the observations in our sample, as well as to obtain coefficient estimates for the time-invariant variables such as race and maternal education. This would not be feasible with the usual mother fixed effects estimation. We obtain modest but significant effects of both birth weight and the fetal growth rate on math and reading scores, with the effects concentrated in the low birth weight range. Infant health measures appear to explain little of the well-documented racial disparity in test scores.

Neurodevelopmental outcomes of infants born prematurely

Long-term follow-up of infants born prematurely is necessary to determine neurodevelopmental outcomes, particularly with the expansion of interest from major disabilities to high prevalence/low severity dysfunctions. Models of pathogenesis include changes due to developmental disruptions and to injury, the magnitude and type of change influenced by the infant's age, and central nervous system recovery and reorganization. Alterations in neurogenesis, migration, myelination, cell death, and synaptogenesis occur even in the absence of insult. Despite increased knowledge regarding these processes, the functional significance of brain abnormalities is unclear. Because of methodologic problems in follow-up studies, it is difficult to characterize outcome definitively. Nonetheless, an acceptable degree of agreement across studies is found with regard to specific neurodevelopmental outcomes: motor/neurologic function, visuomotor integrative skills, IQ, academic achievement, language, executive function, and attention-deficit hyperactivity disorder/behavioral issues. In general, children born prematurely have more problems in these areas than do their normal birth weight counterparts. Suggestions for improved analyses and clarification of outcomes include use of cluster analysis, structural equation modeling, growth curve analysis, developmental epidemiologic approaches, and better control of background variables using risk indexes and factor scores. Better assessment techniques measuring functions documented to be at higher risk of problems are discussed.

Basic numerical processes in very preterm children: a critical transition from preschool to school age

BACKGROUND

Serious difficulties in formal mathematical skills have been identified in preterm children. By contrast, basic-level numerical skills like magnitude judgments have not yet been tested in these children.

AIMS

The aim of the present research was to investigate whether preterm birth also affects these basic numerical abilities, with particular attention to the transition from preschool to formal education.

METHOD

One hundred-forty very preterm children and 60 age-matched controls were recruited in a cross-sectional study at 6 and 8years of age. Magnitude comparison tasks with non-symbolic dot displays or symbolic Arabic-number stimuli, measuring accuracy and reaction time, were administered to participants. We also investigated explicit number knowledge, as well as general cognitive developmental levels, to gain a broader picture of preterm abilities.

RESULTS

Despite no general cognitive delay, the more simple approximate non-symbolic representation of numerical magnitude was affected by preterm birth, with slower reaction times at both ages compared to controls. Additionally, clear difficulties in the construction of the symbolic representation of numerical magnitude and in explicit number knowledge emerged in the 6-year-old preterm children, with a recovery from this serious delay finally by 8years.

CONCLUSIONS

The serious delays identified here in basic numerical abilities in preterm children, despite normal IQ, point to the need for further studies in order to elucidate the relationship between basic numerical abilities and subsequent difficulties in formal mathematic achievement at school.

Relation of neural structure to persistently low academic achievement: a longitudinal study of children with differing birth weights

OBJECTIVE

This study examined the relation of cerebral tissue reductions associated with VLBW to patterns of growth in core academic domains.

METHOD

Children born <750 g, 750 to 1,499 g, or >2,500 g completed measures of calculation, mathematical problem solving, and word decoding at time points spanning middle childhood and adolescence. K. A. Espy, H. Fang, D. Charak, N. M. Minich, and H. G. Taylor (2009, Growth mixture modeling of academic achievement in children of varying birth weight risk, Neuropsychology, Vol. 23, pp. 460-474) used growth mixture modeling to identify two growth trajectories (clusters) for each academic domain: an average achievement trajectory and a persistently low trajectory. In this study, 97 of the same participants underwent magnetic resonance imaging (MRI) in late adolescence, and cerebral tissue volumes were used to predict the probability of low growth cluster membership for each domain.

RESULTS

Adjusting for whole brain volume (wbv), each 1-cm(3) reduction in caudate volume was associated with a 1.7- to 2.1-fold increase in the odds of low cluster membership for each domain. Each 1-mm(2) decrease in corpus callosum surface area increased these odds approximately 1.02-fold. Reduced cerebellar white matter volume was associated specifically with low calculation and decoding growth, and reduced cerebral white matter volume was associated with low calculation growth. Findings were similar when analyses were confined to the VLBW groups.

CONCLUSIONS

Reduced volume of structures involved in connectivity, executive attention, and motor control may contribute to heterogeneous academic trajectories among children with VLBW.

Assessing interchangeability at cluster levels with multiple-informant data

Studies examining the relationship between neighborhood social disorder and health often rely on multiple informants. Such studies assume interchangeability of the latent constructs derived from multiple-informant data. Existing methods examining this assumption do not clearly delineate the uncertainty at individual levels from that at neighborhood levels. We propose a multilevel variance component factor model that allows this delineation. Data come from a survey of a representative sample of children born between 1983 and 1985 in the inner city of Detroit and nearby middle-class suburbs. Results indicate that the informant-level models tend to exaggerate the effect of places because of differences between persons. Our evaluations of different methodologies lead to the recommendation of the multilevel variance component factor model whenever multiple-informant reports can be aggregated at a neighborhood level.

Revisiting the effect of maternal smoking during pregnancy on offspring birthweight: a quasi-experimental sibling analysis in Sweden

Maternal smoking during pregnancy (SDP) seems associated with reduced birthweight in the offspring. This observation, however, is based on conventional epidemiological analyses, and it might be confounded by unobserved maternal characteristics related to both smoking habits and offspring birth weight. Therefore, we apply a quasi-experimental sibling analysis to revisit previous findings. Using the Swedish Medical Birth Register, we identified 677,922 singletons born between 2002 and 2010 from native Swedish mothers. From this population, we isolated 62,941 siblings from 28,768 mothers with discrepant habits of SDP. We applied conventional and mother-specific multilevel linear regression models to investigate the association between maternal SDP and offspring birthweight. Depending on the mother was light or heavy smoker and the timing of exposition during pregnancy (i.e., first or third trimester), the effect of smoking on birthweight reduction was between 6 and 78 g less marked in the sibling analysis than in the conventional analysis. Sibling analysis showed that continuous smoking reduces birthweight by 162 grams for mothers who were light smokers (1 to 9 cigarettes per day) and 226 g on average for those who were heavy smokers throughout the pregnancy in comparison to non-smoker mothers. Quitting smoking during pregnancy partly counteracted the smoking-related birthweight reduction by 1 to 29 g, and a subsequent smoking relapse during pregnancy reduced birthweight by 77 to 83 g. The sibling analysis provides strong evidence that maternal SDP reduces offspring birthweight, though this reduction was not as great as that observed in the conventional analysis. Our findings support public health interventions aimed to prevent SDP and to persuade those who already smoke to quit and not relapse throughout the pregnancy. Besides, further analyses are needed in order to explain the mechanisms through which smoking reduces birthweight and to identify other maternal characteristics that are common causes of both birthweight reduction and maternal smoking.

Emerging executive skills in very preterm children at 2 years corrected age: a composite assessment

Executive Function (EF) deficits have previously been identified in preterm children. However, only recently have emerging executive functions been studied in preschool children who were born preterm without major brain damage. Our study provides a broad assessment of EFs in 72 extremely preterm births (gestational age < 34 weeks and birth weight < 2500 g) and 73 full-term children, born between 2006 and 2008, at 24 months of corrected age. Three factors were extracted from the EF administered measures: working memory, cognitive flexibility, and impulsivity control. Only cognitive flexibility was found to discriminate preterm children from controls.

Program for expectant and new mothers: a population-based study of participation

BACKGROUND

The Manitoba Healthy Baby Program is aimed at promoting pre- and perinatal health and includes two components: 1) prenatal income supplement; 2) community support programs. The goal of this research was to determine the uptake of these components by target groups.

METHODS

Data on participation in each of the two program components were linked to data on all hospital births in Manitoba between 2004/05 through 2007/08. Descriptive analyses of participation by maternal characteristics were produced. Logistic regression analyses were conducted to identify factors associated with participation in the two programs. Separate regressions were run for two groups of women giving birth during the study period: 1) total population; 2) those receiving provincial income assistance during the prenatal period.

RESULTS

Almost 30% of women giving birth in Manitoba received the Healthy Baby prenatal income supplement, whereas only 12.6% participated in any community support programs. Over one quarter (26.4%) of pregnant women on income assistance did not apply for and receive the prenatal income supplement, despite all being eligible for it. Furthermore, 77.8% of women on income assistance did not participate in community support programs. Factors associated with both receipt of the prenatal benefit and participation in community support programs included lower SES, receipt of income assistance, obtaining adequate prenatal care, having completed high school and having depressive symptoms. Having more previous births was associated with higher odds of receiving the prenatal benefit, but lower odds of attending community support programs. Being married was associated with lower odds of receiving the prenatal benefit but higher odds of participating in community support programs.

CONCLUSIONS

Although uptake of the Healthy Baby program in Manitoba is greater for women in groups at risk for poorer perinatal outcomes, a substantial number of women eligible for this program are not receiving it; efforts to reach these women should be enhanced.

Developmental status of 5-year-old moderate low birth weight children

BACKGROUND

Low birth weight (LBW or birth weight<2500 g) is one of the most serious children problems in today's world. The purpose of this study was to evaluate and compare developmental status of moderately LBW (birth weight: 1500-2499 g) children at the age of five to that of normal birth weight (NBW: birth weight: 2500-4000 g) ones.

METHODS

In a case-control study, developmental status of five year old children referred for vaccination between December 2008 and June 2009 in Yazd-Iran, evaluated via Persian version of 60-month Ages and Stages Questionnaires (ASQ). NBW and MLBW children were selected as control and case groups, respectively.

RESULTS

Frequency of developmental delay in gross motor, fine motor and problem solving domains were significantly higher in MLBW group and mean score in all developmental domains was statistically significant lower in case group.

CONCLUSION

LBW is one of risk factors for developmental delay. So, evaluation and monitoring of development status of LBW should be emphasized for early and timely diagnosis, investigation, management and also rehabilitation.

Neurocognitive profiles of preterm infants randomly assigned to lower or higher hematocrit thresholds for transfusion

OBJECTIVE

Preterm infants are frequently transfused with red blood cells based on standardized guidelines or clinical concerns that anemia taxes infants' physiological compensatory mechanisms and thereby threatens their health and well-being. The impact of various transfusion guidelines on long-term neurocognitive outcome is not known. The purpose of this study is to evaluate long-term neurocognitive outcome on children born prematurely and treated at birth with different transfusion guidelines.

METHODS

Neurocognitive outcomes were examined at school age for 56 preterm infants randomly assigned to a liberal (n = 33) or restrictive (n = 23) transfusion strategy. Tests of intelligence, achievement, language, visual-spatial/motor, and memory skills were administered. Between-group differences were assessed.

RESULTS

Those in the liberal transfusion group performed more poorly than those in the restrictive group on measures of associative verbal fluency, visual memory, and reading.

CONCLUSIONS

Findings highlight possible long-term neurodevelopmental consequences of maintaining higher hematocrit levels.

Parental monitoring at age 11 and smoking initiation up to age 17 among Blacks and Whites: a prospective investigation

INTRODUCTION

Parental monitoring has been identified as a predictor of adolescent smoking initiation. However, it is uncertain if the association is uniform across different racial groups.

METHODS

Random samples of low birth-weight and normal birth-weight children were drawn from newborn discharge lists (1983-1985) of two major hospitals in southeast Michigan, one serving an inner city and the other serving suburbs. Assessments occurred at ages 6, 11, and 17 years. Statistical analysis was conducted on children with data on parent monitoring at age 11 and tobacco use at age 17 who had never smoked a cigarette up to age 11 (n = 572). Multiple logistic regression was used to examine the association between parent monitoring and children's smoking initiation. Two-way interactions were tested.

RESULTS

The relationship between parent monitoring at age 11 and child smoking initiation from ages 11 to 17 varied by race. Among White children, an increase of 1 point on the parent monitoring scale signaled an 11% reduction in the odds of initiating smoking by age 17. In contrast, parent monitoring was not significantly associated with smoking initiation among Black children.

DISCUSSION

The results suggest a differential influence of parent monitoring on adolescent smoking between White and Black children. Future research would benefit from close attention to parental goals and concerns and to extra-familial factors that shape smoking behavior across racially and socially disparate communities.

Neurodevelopmental outcome of the premature infant

Advances in antenatal medicine and neonatal intensive care have successfully resulted in improved survival rates of preterm infants. These improvements have been most dramatic in infants born extremely low birth weight (ELBW, <or=1000 g) and at the limits of viability (22 to 25 weeks). But improvements in survival have not been accompanied by proportional reductions in the incidence of disability in this population. Thus, survival is not an adequate measure of success in these infants who remain at high risk for neurodevelopmental and behavioral morbidities. There is now increasing evidence of sustained adverse outcomes into school age and adolescence, not only for ELBW infants but for infants born late preterm.

Early school-based learning difficulties in children born very preterm

BACKGROUND

Educational underachievement is a major morbidity associated with very preterm (VPT) birth. However, few studies have examined early school outcomes with most employing global, clinic based measures.

OBJECTIVE

To examine the early school achievement in a cohort of children born VPT and studied to age 6 years.

METHODS

A regional cohort of 102 VPT children (</=33 weeks GA) were followed prospectively alongside a comparison group of 108 full term (FT) children born during the same period (1998-2000). At 6 years corrected age, all children underwent a comprehensive neurodevelopmental evaluation that included the Woodcock-Johnson Tests of Achievement (WJ-III), teacher report and national numeracy and literacy test results. Rates of specific learning disabilities (LD) were also examined.

RESULTS

VPT children performed less well than FT children on WJ-III subtests (ps<.05), national tests (ps<.01), and in all curricular areas rated by teachers (ps<.01) except expressive language. Even VPT children without severe neurodevelopmental impairment scored lower on the WJ-III math, national tests (ps<.05) and were 2-3 times more likely to show delays (ps<.02) in math (43% vs. 19%), written language (36% vs. 22%), language comprehension (26% vs. 14%), handwriting (36% vs. 17%), spelling (38% vs. 30%) and physical education (33% vs. 11%). They were also twice as likely as FT children to have math LD (47% vs. 21%).

CONCLUSIONS

By age 6, a substantial proportion of VPT children are lagging behind their FT peers across multiple curriculum areas, with difficulties being most prominent in math. Findings highlight the need for early identification and educational supports to help maximise VPT children's learning opportunities during the transition to school.

Positive screening for autism in ex-preterm infants: prevalence and risk factors

OBJECTIVE

The survival of very low birth weight infants has increased markedly in recent years. Unfortunately, the prevalence of significant and lifelong motor, cognitive, and behavioral dysfunction has remained a major problem confronting these children. The objective of this study was to perform screening tests for early autistic features in children with a history of very low birth weight and to identify risk factors associated with a positive screening result.

METHODS

We studied 91 ex-preterm infants < or = 1500 g at birth. Infants underwent conventional MRI studies at preterm and/or term-adjusted age. We collected pertinent demographic, prenatal, intrapartum, acute postnatal, and short-term outcome data for all infants. Follow-up assessments were performed at a mean age of 21.9 +/- 4.7 months, using the Modified Checklist for Autism in Toddlers, the Vineland Adaptive Behavior Scale, and the Child Behavior Checklist.

RESULTS

Twenty-six percent of ex-preterm infants had a positive result on the autism screening tool. Abnormal scores correlated highly with internalizing behavioral problems on the Child Behavior Checklist and socialization and communication deficits on the Vineland Scales. Lower birth weight, gestational age, male gender, chorioamnionitis, acute intrapartum hemorrhage, illness severity on admission, and abnormal MRI studies were significantly associated with an abnormal autism screening score.

CONCLUSIONS

Early autistic behaviors seem to be an underrecognized feature of very low birth weight infants. The results from this study suggest that early screening for signs of autism may be warranted in this high-risk population followed by definitive autism testing in those with positive screening results.

Role of cash in conditional cash transfer programmes for child health, growth, and development: an analysis of Mexico's Oportunidades

BACKGROUND

Many governments have implemented conditional cash transfer (CCT) programmes with the goal of improving options for poor families through interventions in health, nutrition, and education. Families enrolled in CCT programmes receive cash in exchange for complying with certain conditions: preventive health requirements and nutrition supplementation, education, and monitoring designed to improve health outcomes and promote positive behaviour change. Our aim was to disaggregate the effects of cash transfer from those of other programme components.

METHODS

In an intervention that began in 1998 in Mexico, low-income communities (n=506) were randomly assigned to be enrolled in a CCT programme (Oportunidades, formerly Progresa) immediately or 18 months later. In 2003, children (n=2449) aged 24-68 months who had been enrolled in the programme their entire lives were assessed for a wide variety of outcomes. We used linear and logistic regression to determine the effect size for each outcome that is associated with a doubling of cash transfers while controlling for a wide range of covariates, including measures of household socioeconomic status.

FINDINGS

A doubling of cash transfers was associated with higher height-for-age Z score (beta 0.20, 95% CI 0.09-0.30; p<0.0001), lower prevalence of stunting (-0.10, -0.16 to -0.05; p<0.0001), lower body-mass index for age percentile (-2.85, -5.54 to -0.15; p=0.04), and lower prevalence of being overweight (-0.08, -0.13 to -0.03; p=0.001). A doubling of cash transfers was also associated with children doing better on a scale of motor development, three scales of cognitive development, and with receptive language.

INTERPRETATION

Our results suggest that the cash transfer component of Oportunidades is associated with better outcomes in child health, growth, and development.

Reports of birthweight by adolescents and their mothers: comparing accuracy and identifying correlates

Birthweight is associated with health outcomes throughout the lifespan. Official birthweight records are not always available, and researchers must rely on self-reports for birthweight information. This study evaluates the accuracy of adolescent self-reports of birthweight, using medical records as a standard, and compares it with maternal reports. It also examines potential correlates of accuracy. Respondents are 17-year-old adolescents and their mothers, who participated in a follow-up study of randomly selected samples from newborn discharge lists (1983-85) of two major hospitals in south-east Michigan. Nearly one-quarter of the adolescents stated that they did not know their own birthweight, with males twice as likely as females to respond 'don't know'. In addition, self-reports of birthweight among the remaining adolescents were inaccurate, and accuracy was inversely related to birthweight. While maternal reports of offspring's birthweight are highly accurate across diverse subgroups of the population, adolescent self-reports of birthweight are unlikely to be useful in medical research.

Are children of moderately low birth weight at increased risk for poor health? A new look at an old question

OBJECTIVE

The goal was to examine whether moderately low birth weight children were at greater risk for health problems than normal birth weight children in a nationally representative sample of US children.

METHODS

Data were analyzed for 7817 children, 0 to 12 years of age, from the sample child file of the 2002 National Health Interview Survey. Logistic regressions were estimated to examine whether morbidity rates were higher among moderately low birth weight children than among normal birth weight children and to control for covariates. Health was measured as having a special health care need, having a chronic condition, being hospitalized in the past year, having a learning disability, attention-deficit disorder/attention-deficit/hyperactivity disorder, or other behavioral disorders, having minor health conditions, and having acute illnesses.

RESULTS

With control for other confounders, moderately low birth weight children were significantly more likely than normal birth weight children to be identified as having a special health care need, having a chronic condition, having a learning disability, and having attention-deficit disorder or attention-deficit/hyperactivity disorder. They were not more likely to have a hospitalization in the past year, other behavioral disorders, or minor health conditions or acute illnesses.

CONCLUSIONS

This population-based study of rates of current morbidity shows that moderately low birth weight children born since 1990 are vulnerable to a wide range of health, learning, and behavioral problems, compared with normal birth weight children. This suggests the need for continued focus on ways to reduce morbidity rates for moderately low birth weight children.

A longitudinal study of reading skills among very-low-birthweight children: is there a catch-up?

OBJECTIVE

To examine the development of reading skills among very-low-birthweight (VLBW) children and to what extent reading difficulties at 9 years of age persist unchanged, are attenuated, or are enhanced at 15 years of age.

METHODS

Fifty-six VLBW and 52 normal birthweight (NBW) children were assessed on word decoding, word recognition, and reading comprehension at 9 and 15 years of age.

RESULTS

VLBW children showed deficits in reading skill at 9 years of age, while most differences obtained at 15 years of age did not reach significance. VLBW children improved their reading comprehension between 9 and 15 years of age more than NBW children, and when controlling for individual differences in IQ, VLBW children improved both their reading comprehension and word-recognition skill.

CONCLUSION

The results suggest that VLBW children display positive changes over time in reading skills.

Neurodevelopmental outcomes of infants born prematurely

Long-term follow-up of infants born prematurely is necessary to determine neurodevelopmental outcomes, particularly with the expansion of interest from major disabilities to high prevalence/low severity dysfunctions. Models of pathogenesis include changes due to developmental disruptions and to injury, the magnitude and type of change influenced by the infant's age, and central nervous system recovery and reorganization. Alterations in neurogenesis, migration, myelination, cell death, and synaptogenesis occur even in the absence of insult. Despite increased knowledge regarding these processes, the functional significance of brain abnormalities is unclear. Because of methodologic problems in follow-up studies, it is difficult to characterize outcome definitively. Nonetheless, an acceptable degree of agreement across studies is found with regard to specific neurodevelopmental outcomes: motor/neurologic function, visuomotor integrative skills, IQ, academic achievement, language, executive function, and attention-deficit hyperactivity disorder/behavioral issues. In general, children born prematurely have more problems in these areas than do their normal birth weight counterparts. Suggestions for improved analyses and clarification of outcomes include use of cluster analysis, structural equation modeling, growth curve analysis, developmental epidemiologic approaches, and better control of background variables using risk indexes and factor scores. Better assessment techniques measuring functions documented to be at higher risk of problems are discussed.

The lingering academic deficits of low birth weight children

OBJECTIVE

To estimate the influence of low birth weight (LBW; < or =2500 g) on academic achievement in reading and mathematics in 12th grade in 2 socioeconomically and racially disparate, geographically defined communities.

METHODS

Representative samples of LBW and normal birth weight (NBW) children who were born in 1983-1985 and were from the inner city of Detroit and nearby middle class suburbs were assessed longitudinally. Woodcock-Johnson Psycho-Educational Battery-Revised standardized tests of reading and mathematics were used at ages 11 and 17 (n = 773). Multiple regression analysis applying generalized estimating equations was used to assess the independent effects of LBW on test scores.

RESULTS

Compared with NBW children, LBW children manifested deficits of 3 to 5 points in age-standardized tests of academic achievement at age 17 that had persisted with little change from age 11. LBW-related deficits were similar in urban and suburban communities and were independent of family factors. At age 17, LBW children were approximately 50% more likely than NBW children to score below the standardized population mean in both reading and mathematics. The LBW-related deficits in academic achievement in adolescence were largely accounted for by LBW-related deficits in general cognitive abilities, measured by IQ tests at age 6.

CONCLUSIONS

Interventions to address the lingering effects of LBW on the acquisition of core academic skills during the school years should focus on preschool LBW children in both inner city and suburban communities.

"Womb" literacy: reading to infants in the NICU

PROMOTING LITERACY IS NOT generally one of the top priorities in the care of high-risk infants in the NICU. Basic survival and tending to medical needs are obviously the most pressing concerns. However, we know from various studies that high-risk infants are at greater risk for less-than-optimal cognitive outcomes.1–3 For example, preterm infants are at greater risk than term infants for lower overall IQ scores, repeating a grade, and failing to graduate from high school.1,2 Interventions to improve the academic achievement of children are most effective when begun in the preschool years.4

Brain volumes in adult survivors of very low birth weight: a sibling-controlled study

OBJECTIVES

To establish whether adults who were born very low birth weight (VLBW) show altered volumes of certain brain structures.

METHODS

Unmatched case-control study was conducted of 33 individuals from a cohort of VLBW (<1500 g) infants who were born between 1966 and 1977 and 18 of their normal birth weight siblings. Whole brain, gray matter, ventricular, corpus callosum, and hippocampal volumes were measured on structural magnetic resonance imaging scans.

RESULTS

VLBW individuals had a 46% increase in total ventricular volume and a 17% reduction in posterior corpus callosum volume. No differences in whole brain, gray matter, or hippocampal volumes were observed.

CONCLUSION

Specific differences exist in the volumes of certain brain structures in adults who were born VLBW compared with their normal birth weight siblings.