Birth weight and cognitive function in the British 1946 birth cohort: longitudinal population based study

Executive functions of postweaning protein malnutrition in mice

It is well known that nutritional status during the fetal and/or lactation period is important for the development of the central nervous system (CNS). In contrast, the effect of malnutrition on postweaning development has not yet been thoroughly investigated. In the present study, we analyzed the behavioral and neuroanatomical effects of protein malnutrition (PM) postweaning in mice. Starting at 20-21 d of age, male ddY mice were maintained on a 5% casein diet (PM group) or 20% casein diet (control group) for 20 d. On the 20th d, body and brain weights of PM mice were lower than those of the control group. PM mice exhibited excessive alertness and spontaneous activity under novel conditions in the Irwin test. In addition, PM mice showed increased open arm exploration in the elevated plus maze compared to control mice. These results suggest that hyperactivity and reduced anxiety behavior or higher impulsiveness in PM mice could be due to an immature brain.

Association between birthweight and cognitive function in middle age: the atherosclerosis risk in communities study

PURPOSE

We aimed to examine the relationship of birthweight to cognitive performance in middle aged participants of the Atherosclerosis Risk in Communities Study (ARIC).

METHODS

Cognitive function, assessed by means of three neuropsychological tests-the Delayed Word Recall Test (DWR), the Digit Symbol Subtest of the Wechsler Adult Intelligence Scale-Revised (DSS/WAIS-R), and the Word Fluency (WF) Test, was evaluated in relation to birthweight, as recalled through standardized interviews, by the use of data from the second and fourth follow-up visits of the Atherosclerosis Risk in Communities study cohort (1990-1992 and 1996-1998, respectively). Overall, 6785 participants satisfied the inclusion criteria and were included in the analysis.

RESULTS

After adjusting for adult sociodemographic factors, childhood socioeconomic environment and parental risk factors, and adult anthropometric, health status-related. and behavioral variables, we observed linear trends for the relationship of birthweight to WF scores, although the trend was statistically significant only for those reporting exact birthweights (p for trend = .004). For the other cognitive test results, results were either null or inconsistent with the a priori hypotheses.

CONCLUSIONS

Except for WF in those reporting exact birthweights, our study does not support the notion that birthweight influences cognitive function in adults.

Patterns of fetal heart rate response at ∼30 weeks gestation predict size at birth

There is evidence that fetal exposure to maternal stress is associated with adverse birth outcomes. Less is known about the association between fetal responses to a stressor and indicators of fetal maturity and developmental outcomes. The purpose of the present study was to determine whether fetal heart rate (FHR) patterns in response to a startling stimulus at ∼30 weeks of gestation were associated with gestational age at birth and birth weight. FHR was measured in 156 maternal-fetal dyads following a vibroacoustic stimulus. All pregnancies were singleton intrauterine pregnancies in English-speaking women who were primarily married, middle class, White and at least 18 years of age. Group-based trajectory modeling identified five groups of fetuses displaying distinctive longitudinal trajectories of FHR response to the startling stimulus. The FHR group trajectories were significantly associated with birth weight percentile (P < 0.01) even after controlling for estimated fetal weight at the time of assessment and parity, which are the known factors influencing birth weight (P < 0.01). Post hoc analyses indicated that two groups accounted for the association between FHR patterns and birth weight. The group (n = 23) with the lowest birth weight exhibited an immediate FHR deceleration followed by an immediate acceleration that does not recover. An FHR pattern characterized by immediate and fast acceleration to the peak and a slow discovery to baseline was associated with the highest birth weight. This is the first direct evidence showing that low birth weight and the resulting neurological consequences may have their origins in early fetal development.

A life course approach to the development of mental skills

A wide variety of factors across the life course jointly influence cognitive and emotional development. Indeed, research from a variety of disciplines strongly suggests that cognition and mental health are intertwined across the life course, by their common antecedents and underlying physiology in development and in their interplay across adult and later life. We suggest that cognitive and socioemotional function fuse to form skills for life supporting self-regulation, competence, and quality of life that persist into later life through linked reciprocal processes of genetic influence, nurturing, schooling, work, and lifestyle.

Duration of gestation, size at birth and later childhood behaviour

Although many previous studies have reported an association between preterm birth or small size at birth and later behaviour, multiple methodological limitations threaten the validity of causal inferences from reported associations. The authors have examined the association between gestational age and gestational age-specific size at birth (weight, length and head circumference) and behaviour in a large sample of children born healthy at term. The data were from the 6.5-year follow-up of 13,889 Belarusian children who participated in the Promotion of Breastfeeding Intervention Trial, a cluster-randomised trial of a breast-feeding promotion intervention. Child behaviour was measured using the parent and teacher versions of the Strengths and Difficulties Questionnaire (SDQ). Differences in SDQ scores by gestational age and by birthweight, birth length and birth head circumference standardised for gestational age and sex (z-scores) were analysed after controlling for potentially confounding maternal and family factors. There was no association between gestational age and child behaviour after adjusting for potential confounding factors. Lower birthweight-for-gestational age was associated with higher scores in problem behaviours including total difficulties, conduct problems, hyperactivity, emotional symptoms and peer problems. Similar but smaller differences were observed with birth length and birth head circumference, but those differences were attenuated with adjustment for birthweight. The patterns of association were consistent in both parent and teacher assessments. Among school-age children born at term within normal range of birthweight, fetal growth, but not gestational age, was associated with behavioural problem scores.

Vulnerability of the fetal primate brain to moderate reduction in maternal global nutrient availability

Moderate maternal nutrient restriction during pregnancy occurs in both developing and developed countries. In addition to poverty, maternal dieting, teenage pregnancy, and uterine vascular problems in older mothers are causes of decreased fetal nutrition. We evaluated the impact of global 30% maternal nutrient reduction (MNR) on early fetal baboon brain maturation. MNR induced major cerebral developmental disturbances without fetal growth restriction or marked maternal weight reduction. Mechanisms evaluated included neurotrophic factor suppression, cell proliferation and cell death imbalance, impaired glial maturation and neuronal process formation, down-regulation of gene ontological pathways and related gene products, and up-regulated transcription of cerebral catabolism. Contrary to the known benefits from this degree of dietary reduction on life span, MNR in pregnancy compromises structural fetal cerebral development, potentially having an impact on brain function throughout life.

Pre- and perinatal predictors of startle eye blink reaction and prepulse inhibition in healthy neonates

The present study examined the startle eye blink reflex and prepulse inhibition (PPI) in 65 healthy term-born neonates. Although the startle eye blink is already present at birth, some relevant neuronal structures are not fully mature. We therefore investigated the relationship between prenatal maturation and perinatal stress experience on startle eye blink and PPI. Eye blinks were evoked by unilaterally presented acoustic broadband white noise (50 ms, 95 dB, prepulse 75 dB). Startle response magnitude and percent PPI were calculated for ipsilateral and contralateral side of stimulation. Neonates exhibited stronger startle responses ipsilaterally than contralaterally, and a significant PPI. Neonates with more prenatal growth and less perinatal stress had greater startle magnitudes. Neonates with more stress had more PPI contralaterally. Results suggest that startle eye blinks may be useful as indicators of prenatal maturation and perinatal stress.

Season of birth and childhood intelligence: Findings from the Aberdeen Children of the 1950s cohort study

BACKGROUND

In this study, 2 main hypotheses have been put forward to explain the variation in childhood intelligence or school performance by season of birth. In the first hypothesis, it is suggested that it is due to school policy concerning school entry, whereas the second suggests that a seasonally patterned exposure such as temperature, maternal nutrition, or infection during critical periods of brain development have a lasting effect on intelligence.

AIMS

To determine whether childhood performance on tests of different domains of intelligence is patterned by season of birth and to examine possible mechanisms for any associations.

SAMPLE

12,150 individuals born in Aberdeen, Scotland between 1950 and 1956.

METHODS

Birth cohort study in which the variation in different domains of childhood intelligence measured at ages 7, 9, and 11 by season of birth were examined.

RESULTS

Reading ability at age 9 and arithmetic ability at age 11 varied by season of birth, with lowest scores among those born in autumn or early winter (September-December) and highest scores among those born in later winter or spring (February-April); p=.002 for joint sine-cosine functions for reading ability at age 9 and p=.05 for sine-cosine function for arithmetic ability at age 11. The child's perception and understanding of pictorial differences at age 7, verbal reasoning at 11, and English language ability at 11 did not vary by season of birth. Age at starting primary school and age relative to class peers were both associated with the different measurements of childhood intelligence and both attenuated the association between month of birth and reading ability at age 9 and arithmetic ability at age 11 towards the null. Both adjusted and unadjusted differences in reading ability at age 9 and arithmetic ability at age 11 between those born from September to December compared with other times of the year were less than 0.1 of a standard deviation of the test scores. Ambient temperature around the time of conception, during gestation, and around the time of birth did not affect intelligence.

CONCLUSION

Any variation in mean childhood intelligence by season of birth is weak and largely explained by age at school entry and age relative to class peers.

Relationship between birth head circumference and adulthood quality of life in Chinese people

AIM

To determine the relationship between birth size and later QOL for Chinese people.

METHODS

Birth data of 1074 subjects were obtained from obstetric birth records of Peking Union Medical College Hospital. All subjects are interviewed face to face with the 36-Item Short-Form Health Survey scale by trained investigators. Linear regression model was used to analyse the relationship between QOL and birth head circumference of the subjects after adjusting for the childhood and adulthood characteristics. The relationship was described with regression coefficients (B) and its 95% confidence interval (CI).

RESULTS

The mean weighted score of QOL was 88.1 ± 9.1, ranging from 76.8 to 100. Larger birth head circumference meant higher adulthood QOL total score (P= 0.001). After controlling the adulthood confounders, as compared to larger head circumference (≥33 cm), small (<31 cm) and medium head circumferences (31-33 cm) meant lower adulthood QOL scores (B=-2.356, P= 0.005 and B=-1.645, P= 0.014, respectively). The increase of head circumference by 1 cm was associated with 0.480 (95% CI: 0.141, 0.820) increase of QOL score after adjusting adulthood confounders (P= 0.006).

CONCLUSIONS

This study validated the relationship between birth head circumference and QOL in later life. Smaller head circumference at birth could predict worse adulthood QOL at above 50 years old.

The effect of intrauterine growth on verbal IQ scores in childhood: a study of monozygotic twins

OBJECTIVE

Given the adverse neurobiological effects of suboptimal nutrition on the developing brain, it is of social and medical importance to determine if the global prevalence of poor intrauterine growth causes lasting cognitive deficits. We examined whether suboptimal intrauterine growth relates to impaired cognitive outcome by comparing birth weight and cognition in monozygotic twins and considered whether children within-pair differences in birth weight were related to within-pair differences in IQ scores.

METHODS

A total of 71 monozygotic twin pairs (aged 7 years 11 months to 17 years 3 months) participated. The Wechsler Intelligence Scale for Children, Third Edition, was administered, and verbal IQ (VIQ) and performance IQ (PIQ) scores were calculated. Regression was used to relate within-pair differences in birth weight to within-pair differences in IQ scores.

RESULTS

VIQ but not PIQ score was affected by prenatal growth restriction. The results suggest that the mean advantage for heavier twins relative to their lighter co-twins can be as much as half an SD in VIQ points. In pairs with minimal discordance, heavier twins had lower VIQ scores than their lighter co-twins.

CONCLUSIONS

Our study results suggest that lower birth weight in monozygotic twins can also have a negative long-term impact on cognition both in infants who are small at birth and also those with birth weights across the spectrum. Studying monozygotic twins enabled us to examine the effect of reduced intrauterine growth on cognition independently of confounding factors, including parental IQ and education and infant gender, age, genetic characteristics, and gestation.

Birth weight standardized to gestational age and intelligence in young adulthood: a register-based birth cohort study of male siblings

The authors aimed to determine the relation between birth-weight variations within the normal range and intelligence in young adulthood. A historical birth cohort study was conducted. Data from the Medical Birth Register of Norway were linked with register data from the Norwegian National Conscript Service. The sample comprised 52,408 sibships of full brothers who were born singletons at 37-41 completed weeks' gestation during 1967-1984 in Norway and were intelligence-tested at the time of mandatory military conscription. Generalized estimating equations were used to fit population-averaged panel data models. The analyses showed that in men with birth weights within the 10th-90th percentile range, a within-family difference of 1 standard deviation in birth weight standardized to gestational age was associated with a within-family difference of 0.07 standard deviation (99% confidence interval: 0.03, 0.09) in intelligence score, after adjustment for a range of background factors. There was no significant between-family association after adjustment for background factors. In Norwegian males, normal variations in intrauterine growth are associated with differences in intelligence in young adulthood. This association is probably not due to confounding by familial and parental characteristics.

Gestational stress influences cognition and behavior

The developmental origins of disease or fetal programming model predicts that early exposures to threat or adverse conditions have lifelong consequences that result in harmful outcomes for health. The vast majority of the studies in support of the programming model in human beings are retrospective and most rely on surrogate measures of early experience such as birth weight or preterm birth. Recently, a small number of prospective studies have been reported that have documented the developmental consequences of exposures to stressful intrauterine conditions. These studies of gestational stress have clearly shown that fetal exposures to psychosocial and/or biological markers of adversity have significant and largely negative consequences for fetal, infant and child neurological development. Fetal exposure to stress, especially early in gestation, results in delayed fetal maturation and impaired cognitive performance during infancy and results in decreased brain volume in areas associated with learning and memory in children. The accumulating evidence supports the conclusion that fetal exposure to stress profoundly influences the nervous system, with consequences that persist into childhood and perhaps beyond.

Effect of birth weight, maternal education and prenatal smoking on offspring intelligence at school age

To examine the combined effect of birth weight, mothers' education and prenatal smoking on psychometrically measured intelligence at school age 1,822 children born in 1992-1999 and attending the first six grades from 45 schools representing all of the fifteen Estonian counties with information on birth weight, gestational age and mother's age, marital status, education, parity and smoking in pregnancy, and intelligence tests were studied. The scores of Raven's Standard Progressive Matrices were related to the birth weight: in the normal range of birth weight (>or=2500 g) every 500 g increase in birth weight was accompanied by around 0.7-point increase in IQ scores. A strong association between birth weight and IQ remained even if gestational age and mother's age, marital status, education, place of residence, parity and smoking during pregnancy have been taken into account. Maternal prenatal smoking was accompanied by a 3.3-point deficit in children's intellectual abilities. Marriage and mother's education had an independent positive correlation with offspring intelligence. We concluded that the statistical effect of birth weight, maternal education and smoking in pregnancy on offspring's IQ scores was remarkable and remained even if other factors have been taken into account.

Metabolic imprinting, programming and epigenetics – a review of present priorities and future opportunities

Metabolic programming and metabolic imprinting describe early life events, which impact upon on later physiological outcomes. Despite the increasing numbers of papers and studies, the distinction between metabolic programming and metabolic imprinting remains confusing. The former can be defined as a dynamic process whose effects are dependent upon a critical window(s) while the latter can be more strictly associated with imprinting at the genomic level. The clinical end points associated with these phenomena can sometimes be mechanistically explicable in terms of gene expression mediated by epigenetics. The predictivity of outcomes depends on determining if there is causality or association in the context of both early dietary exposure and future health parameters. The use of biomarkers is a key aspect of determining the predictability of later outcome, and the strengths of particular types of biomarkers need to be determined. It has become clear that several important health endpoints are impacted upon by metabolic programming/imprinting. These include the link between perinatal nutrition, nutritional epigenetics and programming at an early developmental stage and its link to a range of future health risks such as CVD and diabetes. In some cases, the evidence base remains patchy and associative, while in others, a more direct causality between early nutrition and later health is clear. In addition, it is also essential to acknowledge the communication to consumers, industry, health care providers, policy-making bodies as well as to the scientific community. In this way, both programming and, eventually, reprogramming can become effective tools to improve health through dietary intervention at specific developmental points.

Maternal vitamin D status: implications for the development of infantile nutritional rickets

The mother is the major source of circulating 25-hydroxyvitamin D concentration in the young infant. Maternal vitamin D status is an important factor in determining the vitamin D status of the infant and their risk of developing vitamin D deficiency and infantile nutritional rickets. There is evidence that the current supplementation recommendations, particularly for pregnant and lactating women, are inadequate to ensure vitamin D sufficiency in these groups. A widespread and concerted effort is needed to ensure daily supplementation of breastfed and other infants at high risk with vitamin D 400 IU from birth and of pregnant women in high-risk communities with 2000 IU. Future studies are required to determine the optimal doses of vitamin D supplementation in pregnancy and during lactation, and for normalizing vitamin D stores in infancy to reduce the prevalence of infantile nutritional rickets. Operational research studies are needed to understand the best methods of implementing supplementation programs and the factors that are likely to impede their success.

Gestational age differences in health and development among young Swedish men born at term

BACKGROUND

Although increased morbidity and mortality associated with pre-term birth and restricted fetal growth have been extensively studied, relatively little is known about variations in health outcomes among term births, because they are often assumed to be homogeneous.

METHODS

We examined variations in height, body mass index (BMI), systolic and diastolic blood pressure (SBP and DBP), and intellectual performance by gestational age and fetal 'growth' (birth weight for gestational age) among young Swedish men born at term (37-41 weeks of gestation). We also compared the magnitude of associations among 314,642 men from different families and among 72,212 full brothers from 35,215 families to assess whether the associations are explained by familial factors shared by siblings.

RESULTS

Gestational age in completed weeks was positively associated with height [0.11 cm, 95% confidence interval (CI): 0.09-0.13] and intellectual performance (0.01, 95% CI: 0.00-0.02) and negatively associated with SBP (-0.28 mmHg, 95% CI: -0.33 to -0.24), after controlling for birth weight, maternal age at the men's birth, parity, family socio-economic position and family structure. The associations with height and SBP were observed also among brothers within families, suggesting that they are not explained by shared family characteristics. However, the positive association between gestational age and intellectual performance was no longer present within families. Birth weight for gestational age (z-score) was positively associated with height, BMI and intellectual performance and negatively associated with SBP. These associations were robust within families.

CONCLUSIONS

Among young men born at term, fetal growth and even gestational age are independently associated with adult size, BP and cognitive ability. The extent to which shared family characteristics explain the associations varies across outcomes.

Birth weight and cognitive performance in older women: the Rancho Bernardo study

Low birth weight is associated with poorer cognitive function from infancy through early adulthood, but little is known about low birth weight and cognitive performance in the elderly. This study examines the association of birth weight with cognitive function in community-dwelling older women. Participants were 292 community-dwelling women aged 55-89 (median = 71 years) who attended a 1988-91 clinic visit when cognitive function was assessed, and responded to a 1991 mailed questionnaire assessing birth weight. All analyses were adjusted for age and education. Birth weight ranged from 2 to 12 pounds (lbs; mean = 7.4 +/- 1.9). When birth weight was categorized into tertiles (2-6.9 lbs, 7-8 lbs, and 8.1-12.4 lbs), women in the lowest tertile had significantly lower ("poorer") scores on Serial 7's, a test of concentration and calculation (p < 0.05). Other birth weight categorizations (lowest quartile or quintile, or birth weight <5.5 lbs vs. 5.6-8.9 lbs and >or=9 lbs) did not improve the prediction of poor performance on Serial 7's. Birth weight as a continuous variable was significantly and positively associated with Serial 7's test scores (p = 0.04). Results suggest that small decrements in cognitive function tasks involving calculation may persist throughout life in women who were of relatively low birth weight. Although this association could be spurious, it deserves further evaluation.

Association of birthweight and head circumference at birth to cognitive performance in 9- to 10-year-old children in South India: prospective birth cohort study

To examine whether birthweight and head circumference at birth are associated with childhood cognitive ability in South India, cognitive function was assessed using three core tests from the Kaufman Assessment Battery for children and additional tests measuring long-term retrieval/storage, attention and concentration, and visuospatial and verbal abilities among 505 full-term born children (mean age 9.7 y). In multiple linear regression adjusted for age, sex, gestation, socioeconomic status, parent's education, maternal age, parity, body mass index, height, rural/urban residence, and time of testing, Atlantis score (learning ability/long-term storage and retrieval) rose by 0.1 SD per SD increase in newborn weight and head circumference, respectively (p < 0.05 for all), and Kohs' block design score (visuospatial ability) increased by 0.1 SD per SD increase in birthweight (p < 0.05). The associations were reduced after further adjustment for current head circumference. There were no associations of birthweight and/or head circumference with measures of short-term memory, fluid reasoning, verbal abilities, and attention and concentration. In conclusion, higher birthweight and larger head circumference at birth are associated with better childhood cognitive ability. The effect may be specific to learning, long-term storage and retrieval, and visuospatial abilities, but this requires confirmation by further research.

Variation in child cognitive ability by week of gestation among healthy term births

The authors investigated variations in cognitive ability by gestational age among 13,824 children at age 6.5 years who were born at term with normal weight, using data from a prospective cohort recruited in 1996-1997 in Belarus. The mean differences in the Wechsler Abbreviated Scales of Intelligence were examined by gestational age in completed weeks and by fetal growth after controlling for maternal and family characteristics. Compared with the score for those born at 39-41 weeks, the full-scale intelligence quotient (IQ) score was 1.7 points (95% confidence interval (CI): -2.7, -0.7) lower in children born at 37 weeks and 0.4 points (95% CI: -1.1, 0.02) lower at 38 weeks after controlling for confounders. There was also a graded relation in postterm children: a 0.5-points (95% CI: -2.6, 1.6) lower score at 42 weeks and 6.0 points (95% CI: -15.1, 3.1) lower at 43 weeks. Compared with children born large for gestational age (>90th percentile), children born small for gestational age (<10th percentile) had the lowest IQ, followed by those at the 10th-50th percentile and those at the >50th-90th percentile. These findings suggest that, even among healthy children born at term, cognitive ability at age 6.5 years is lower in those born at 37 or 38 weeks and those with suboptimal fetal growth.

Endowments and parental investments in infancy and early childhood

This article tests whether parents reinforce or compensate for child endowments. We estimate how the difference in birth weight across siblings impacts specific parental investments: breast-feeding, well-baby visits, immunizations, and preschool attendance. Our results indicate that normal-birthweight children are 5%-11% more likely to receive early childhood parental investments than their low-birth-weight siblings. Moreover, the presence of additional low-birth-weight siblings in the household increases the likelihood of investments such as well-baby visits and immunizations for normal-birth-weight children. These results suggest that parental investments in early childhood tend to reinforce endowment differences.

No evidence of genetic mediation in the association between birthweight and academic performance in 2,413 Danish adolescent twin pairs

Evidence of a positive association between birthweight and IQ has been established in several studies. Analyses of within twin pair differences in birthweight and IQ have been used to shed light on the basis of the association. The strength of this approach is the possibility of controlling for both unmeasured common childhood-environmental factors as well as genetic factors shared by the co-twins. Two twin studies suggest the existence of genetic mediation between birthweight and IQ, that is, common genetic factors influence both fetal growth and IQ in childhood, while two other twin studies find no evidence of such mediation. In the present study we use a large population-based national register study of 2,413 Danish twin-pairs from birth cohorts 1986-1990, of which we have zygosity information on 74%. We perform individual level as well as intra-pair analyses of birthweight and school achievements at age 16. For both sexes we observed a monotonic increase in academic performance with increasing percentiles of birthweight. However, we did not find that this association is due to genetic mediation.

A life-history model of human fitness indicators

Recent adaptationist accounts of human mental and physical health have reinvigorated the debate over the evolution of human intelligence. In the tradition of strong inference the current study was developed to determine whether either Miller's (1998, 2000a) Fitness Indicator Theory or Rushton's (1985, 2000) Differential-K Theory better accounts for general intelligence ("g") in an undergraduate university population (N=192). Owing to the lengthy administration time of the test materials, a newly developed 18-item short form of the Ravens Advanced Progressive Matrices (APM-18; Sefcek, Miller, and Figueredo 2007) was used. A significant, positive relationship between K and F (r = .31, p < .001) emerged. Contrary to predictions, no significant relationships were found between "g" and either K or F (r = -.09, p > or = .05 and r = .11, p > or = .05, respectively). Though generally contrary to both hypotheses, these results may be explained in relation to antagonistic pleiotropy and a potential failure to derive correct predictions for within-species comparisons directly from the results of between-species comparisons.

Multiple Micronutrient Supplementation during Pregnancy in Developing-Country Settings: Policy and Program Implications of the Results of a Meta-Analysis

Background

An independent Systematic Review Team performed a meta-analysis of 12 randomized, controlled trials comparing multiple micronutrients with daily iron–folic acid supplementation during pregnancy.

Objective

To provide an independent interpretation of the policy and program implications of the results of the meta-analysis.

Methods

A group of policy and program experts performed an independent review of the meta-analysis results, analyzing internal and external validity and drawing conclusions on the program implications.

Results

Although iron content was often lower in the multiple micronutrient supplement than in the iron–folic acid supplement, both supplements were equally effective in tackling anemia. Community-based supplementation ensured high adherence, but some mothers still remained anemic, indicating the need to concomitantly treat infections. The small, significant increase in mean birthweight among infants of mothers receiving multiple micronutrients compared with infants of mothers receiving iron-folic acid is of similar magnitude to that produced by food supplementation during pregnancy. Larger micronutrient doses seem to produce greater impact. Meaningful improvements have also been observed in height and cognitive development of the children by 2 years of age. There were no significant differences in the rates of stillbirth, early neonatal death, or neonatal death between the supplemented groups. The nonsignificant trend toward increased early neonatal mortality observed in the groups receiving multiple micronutrients may be related to differences across trials in the rate of adolescent pregnancies, continuing iron deficiency, and/or adequacy of postpartum health care and merits further investigation.

Conclusions

Replacing iron–folic acid supplements with multiple micronutrient supplements in the package of health and nutrition interventions delivered to mothers during pregnancy will improve the impact of supplementation on birthweight and on child growth and development.

Trait anxiety in pregnant women predicts offspring birth outcomes

The goal of our study was to characterise the relationships between trait anxiety symptoms of women during their pregnancies and birth outcomes of their offspring using a longitudinal cohort from the Maternal Health Practices and Child Development Project. We used the State-Trait Personality Index anxiety measure that is based on Spielberger's State-Trait Anxiety Inventory to measure self-reported trait anxiety at two gestational assessments (fourth and seventh months, representing the first and second trimesters, respectively) and at a third assessment shortly after delivery (representing the third trimester). Demographic, social, psychological, substance use and medical factors were assessed prenatally, and outcomes of the 763 live, singleton births were determined at delivery. In regression models, trait anxiety at the second and third trimesters predicted lower birthweight and shorter birth length, controlling for confounders. Anxiety reported at the third trimester predicted shortened gestational age, controlling for confounders. At the first and second trimesters, the relationship of birthweight and birth length to maternal trait anxiety was only significant for severe anxiety. Women whose anxiety reached severe levels for at least two trimesters were significantly more likely to deliver offspring of lower birthweight and shorter birth length than those women who reported severe anxiety at none or only one of the trimesters. Additionally, offspring of women who experienced severe anxiety during all three trimesters had shorter mean gestational age than offspring of women who did not report severe anxiety at any trimester. Women who report chronic, severe trait anxiety are at the highest risk of having shorter gestations and delivering smaller babies.

Birth weight effects on children's mental, motor, and physical development: evidence from twins data

OBJECTIVE

To determine the effect of very low birth weight (VLBW; <1500 g) and moderately low birth weight (MLBW; 1500-2499 g) on children's mental and motor development and physical growth during the first 2 years of life and whether VLBW and MLBW babies catch up to normal birth weight (NBW; > or =2500 g) children by age 2.

METHODS

We use data on dizygotic (DZ) and monozygotic (MZ) twins and singleton births from the first two waves of the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), a nationally representative dataset of children born in the US in 2001. We estimate the effects of VLBW and MLBW on children's mental and motor development scores, weight-for-age, weight-for-length, weight-for-height, and length-for-age z-scores at 9 months and 2 years. We examine whether differences in outcomes within twin pairs are related to differences in their birth weights. The within-twins analysis is conducted on samples of DZ and MZ twins. For comparison, we also estimate birth weight effects on child outcomes from multivariate linear regression models using the full singleton and twins' sample. We also estimate the effect of being small-for-gestational age (SGA; birth weight <10th percentile for gestation) using the same set of models in order to separate out the effects of fetal growth restriction from prematurity.

RESULTS

Evaluation of all births showed that VLBW and MLBW have large negative effects on mental development, motor development, and growth at 9 months and 2 years of age. However, results from within-twin models with DZ twins that control for shared maternal and environmental factors showed much less effect of birth weight on mental or motor development, but continued large effects on growth for the VLBW group. Within-twin models with MZ twins that control for shared maternal, environmental, and genetic factors showed statistically insignificant effects of birth weight on mental and motor development, but continued effects on growth. Similar patterns were found when examining the effects of SGA.

CONCLUSIONS

After controlling for the influence of maternal, environmental, and genetic factors, low birth weight has at most a small negative effect on children's mental and motor development in their first 2 years of life. However, low birth weight is a major risk factor for children's physical growth in the early years and there is no evidence of catch-up by age 2.

Neuroticism in adolescence and cognitive function in midlife in the British 1946 birth cohort: The HALCyon program

We examined whether higher levels of neuroticism in adolescence were associated with poorer cognitive function in midlife in 2,071 members of the British 1946 birth cohort. Higher neuroticism at age 13 was associated with poorer performance on tests of verbal ability, verbal fluency, and verbal memory at age 53 in sex-adjusted analyses. However, higher neuroticism was also associated with poorer cognitive performance at age 8. After adjustment for childhood cognition or educational attainment, the associations between neuroticism at age 13 and midlife cognition ceased to be statistically significant. The link between neuroticism and subsequent cognitive ability may be a reflection of a long-standing correlation between the stable aspects of these traits since childhood, but further measurements of both traits are needed to confirm this.

Fetal origins of mental health: evidence and mechanisms

The concept of fetal programming states that changes in the fetal environment during sensitive periods of organ development may cause long-lasting changes in the structure and functioning of these organs later in life and influence the risk for chronic diseases such as coronary heart disease and type 2 diabetes. Fetal growth is a summary marker of the fetal environment and is reflected by relatively easy-to-obtain measures of size at birth such as birth weight. In the last two decades, a body of evidence emerged linking fetal growth with behavioural and mental health outcomes later in life. Cognitive functioning and behavioural problems in childhood, in particular inattention/hyperactivity, have been shown to be inversely related to fetal growth. Although results are mixed, risk for personality disorders and schizophrenia seems to be linked with fetal growth and adversity, while the evidence for mood disorders is weak. Vulnerability for psychopathology may also be influenced by prenatal adversity. There is evidence for associations of fetal growth with temperament in childhood as well as stress reactivity and distress. The associations of fetal growth with mental health later in life are potentially caused by specific prenatal factors such as maternal smoking, alcohol, toxins/drugs, nutrition, psychosocial stress and infection during pregnancy. The mechanisms likely involve changes in neurodevelopment and in the set point of neuroendocrine systems, and there is evidence that prenatal adversity interacts with genetic and postnatal environmental factors. Future studies should examine the effects of specific prenatal factors and attempt to disentangle genetic and prenatal environmental effects.

Contribution of parenting factors to the developmental attainment of 9-month-old infants: results from the Japan Children's Study

BACKGROUND

Child development integrates several interdependent domains, but few studies have attempted to identify the common factors that contribute to these different domains of development in infancy. The aim of the present study was to identify the factors that contribute to several domains of developmental attainment in 9-month-old infants.

METHODS

We used data from the Japan Children's Study, a prospective cohort study underway in Japan since 2005. Mothers completed questionnaires about their children's temperament, coparenting behaviors, maternal parenting stress, and parenting behavior. The Kinder infant development scale was used to evaluate child development outcomes.

RESULTS

A total of 270 children were included in this analysis. After adjusting for the children's birth weight, gestational age, temperament, and other family environmental variables, multiple logistic regression analyses showed that greater maternal cognitive stimulation was associated with the development of receptive language, expressive language, social relationships, and feeding. Results also suggest that early supportive coparenting helped to promote development in manipulation, receptive language, and social relationships. Maternal parenting stress was stable between the infant ages of 4 and 9 months and was negatively correlated with scores for coparenting and maternal stimulation, which suggests an indirect effect of maternal parenting stress on child outcomes.

CONCLUSIONS

Supportive coparenting and maternal cognitive stimulation were the most important contributors to most domains of child development. Our findings suggest that educational interventions targeting young families would help parents establish and maintain an environment of successful coparenting and cognitive stimulation as their children grow.

Diet and deprivation in pregnancy

Deprivation is associated with poor pregnancy outcome but the role of nutrition as a mediating factor is not well understood. We carried out a prospective cohort study of 1461 singleton pregnancies in Aberdeen, UK during 2000-6. We measured nutrient intake and supplement use, B vitamin and homocysteine status, birth weight, gestational age, neonatal treatment and socio-economic deprivation status. Women in the most deprived deciles were approximately 6 years younger and half as likely to take folic acid supplements periconceptually as the least deprived mothers. Deprivation was associated with low blood folate, high homocysteine and diets low in protein, fibre and many of the vitamins and minerals. The diets of the more deprived women were also characterised by low intakes of fruit, vegetables and oily fish and higher intakes of processed meat, fried potatoes, crisps and snacks. Deprivation was related to preterm birth (OR 1.14 (95 % CI 1.03, 1.25); P = 0.009) and whether the baby required neonatal treatment (OR 1.07 (95 % CI 1.01, 1.14); P = 0.028). Low birth weight was more common in women consuming diets low in vitamin C (OR 0.79 (95 % CI 0.64, 0.97); P = 0.028), riboflavin (OR 0.77 (95 % CI 0.63, 0.93); P = 0.008), pantothenic acid (OR 0.79 (95 % CI 0.65, 0.97); P = 0.023) and sugars (OR 0.78 (95 % CI 0.64, 0.96); P = 0.017) even after adjustment for deprivation index, smoking, marital status and parity. Deprivation in pregnancy is associated with diets poor in specific nutrients and poor diet appears to contribute to inequalities in pregnancy outcome. Improving the nutrient intake of disadvantaged women of childbearing age may potentially improve pregnancy outcome.

Association of measures of fetal and childhood growth with non-clinical psychotic symptoms in 12-year-olds: the ALSPAC cohort

BACKGROUND

Previous studies have suggested that impaired fetal and childhood growth are associated with an increased risk of schizophrenia, but the association of pre-adult growth with non-clinical psychotic symptoms (psychosis-like symptoms) in children is not known.

AIMS

To explore the associations of body size at birth and age 7.5 years with childhood psychosis-like symptoms.

METHOD

Prospective cohort of children followed up from birth to age 12: the ALSPAC cohort.

RESULTS

Data on 6000 singleton infants born after 37 weeks of gestation. A one standard deviation increase in birth weight was associated with an 18% reduction in the risk of definite psychosis-like symptoms after adjusting for age and gestation (Odds ratio (OR) = 0.82, 95% CI = 0.73-0.92, P = 0.001). This association was partly confounded by maternal anthropometry, smoking during pregnancy, socioeconomic status and IQ. A similar association was seen for birth length and psychosis-like symptoms, which disappeared after controlling for birth weight. There was little evidence for an association of 7-year height or adiposity with psychosis-like symptoms.

CONCLUSIONS

Measures of impaired fetal, but not childhood, growth are associated with an increased risk of psychosis-like symptoms in 12-year-olds.

The black-white test score gap and early home environment

Based on panel data for three age cohorts of children from the Panel Study of Income Dynamics, we examine how early home environment contributes to black-white achievement gaps at different developmental stages and the extent to which early gaps contribute to later racial achievement gaps. We find large black-white test score differences among children of all ages even before children start formal schooling. Except for the oldest cohort, the gaps for all tests widened when children's cognitive skills were assessed six years later. Racial achievement gaps in applied problem scores by grade three and letter-word scores by grade six, can be accounted for by child's characteristics, family socioeconomic background, and mother's cognitive skills. However, these covariates explain an increasingly smaller proportion of the black-white achievement gap as children advance to higher grades. Gaps in early cognitive skills are highly predictive of gaps at later ages, setting off a trajectory of cumulative disadvantage for black children over time. Our results underscore the key role of early home environment and the intergenerational roots of the persistent black-white achievement gap.

Modifiable Midlife Risk Factors for Late-Life Cognitive Impairment and Dementia

The baby boom generation is approaching the age of greatest risk for cognitive impairment and dementia. There is growing interest in strategies to modify the environment in midlife to increase the probability of maintaining cognitive health in late life. Several potentially modifiable risk factors have been studied in relation to cognitive impairment and dementia in late life, but methodological limitations of observational research have resulted in some inconsistencies across studies. The most promising strategies are maintaining cardiovascular health, engagement in mental, physical, and social activities, using alcohol in moderation, abstaining from tobacco use, and following a heart-healthy diet. Other factors that may influence cognitive health are occupational attainment, depression, personality, exposure to general anesthesia, head injury, postmenopausal hormone therapy, non-steroidal anti-inflammatory medications, and nutritional supplements such as antioxidants. Some long-term observational studies initiated in midlife or earlier, and some randomized controlled trials, have examined the effects of specific cognitive health promotion behaviors in midlife on the risk of cognitive impairment in late life. Overall, these studies provide limited support for risk reduction at this time. Recommendations and challenges for developing effective strategies to reduce the burden of cognitive impairment and dementia in the future are discussed.

The risk for impaired learning-related abilities in childhood and educational attainment among adults born near-term

OBJECTIVE

To examine whether near-term births (NTB) and small-for-gestational-age (SGA) infants are at high risk for childhood learning-related problems and poor adult educational attainment, and whether poverty amplifies the adverse effects of NTB and SGA on those outcomes.

METHODS

A randomly selected birth cohort (n = 1,619) was followed into adulthood. IQ and learning abilities were measured in childhood and educational attainment was measured in adulthood.

RESULTS

NTB (n = 226) and SGA (n = 154) were associated with lower educational attainment mediated through learning-related abilities at age 7. Childhood poverty moderated the impact of NTB on educational attainment both directly and mediated through lower learning-related abilities. Poverty did not moderate the effect of SGA.

CONCLUSIONS

Poorer learning-related outcomes and educational attainment were not limited to children born very (<32 weeks) or extremely (<28 weeks) preterm, especially among those living in poverty. Targeted interventions such as remedial learning during childhood among NTB in poor families may yield higher educational attainment.

Parental education and late-life dementia in the United States

We investigated the relation between parental education and dementia in the United States. Participants in the Aging, Demographics, and Memory Study were included, with information regarding parental education obtained from the Health and Retirement Study. The odds of dementia in elderly Americans whose mothers had less then 8 years of schooling were twice (95% CI, 1.1-3.8) that of individuals with higher maternal education, when adjusted for paternal education. Of elderly Americans with less educated mothers, 45.4% (95% CI, 37.4-53.4%) were diagnosed with dementia or ;;cognitive impairment, no dementia'' compared to 31.2% (95% CI, 25.0-37.4%) of elderly Americans whose mothers had at least an 8th grade education. The population attributable risk of dementia due to low maternal education was 18.8% (95% CI, 9.4-28.2%). The education of girls in a population may be protective of dementia in the next generation.

Impact of glucose metabolism and birth size on cognitive performance in elderly subjects

AIMS

We aimed to investigate the impact of diabetes and impaired glucose tolerance on cognitive performance and to explore the association between birth weight and cognitive performance among diabetic subjects.

METHODS

We performed a standard oral glucose tolerance test and a computerised test for assessment of cognitive performance (CogState) in 1243 subjects; 173 of them had type 2 diabetes. At the time of cognitive testing the mean age of the subjects was 64 years. Subjects with type 1 diabetes or a history of stroke were excluded.

RESULTS

Subjects with known diabetes performed significantly poorer in cognitive tasks measuring visual attention, working memory and episodic learning than subjects with normal glucose tolerance. Subjects with newly diagnosed diabetes or milder impairments in glucose regulation did not differ from the normoglycaemic group. A low birth weight enhanced the association between diabetes and poor performance in the working memory and episodic learning tasks.

CONCLUSIONS

Poorer cognitive performance was associated with known type 2 diabetes but not with newly diagnosed diabetes or milder impairments in glucose regulation. Low birth weight was found to be an additional vulnerability factor enhancing cognitive decline in diabetic subjects.

[Education and work in the Pelotas birth cohort from 1982 to 2004-5, Southern Brazil]

OBJECTIVE

To analyze the influence of biological and socioeconomic factors throughout life on entry into the university and insertion in the work force of young adults from the 1982 birth cohort.

METHODS

Longitudinal study of 5,914 births that took place in the city of Pelotas, Southern Brazil, in 1982. Data was collected by means of questionnaires applied on young adults when accompanying the 1982 cohort in 2004-5. Information was gathered concerning educational level and insertion in the labor market. Poisson Regression was utilized to study the effect of demographic and socioeconomic variables, as well as birth weight and maternal breastfeeding, on the outcomes.

RESULTS

On the average, these young adults had 9.4 (+/- 3.1) years of schooling and 42% of them were attending school in 2004-5. One in five young adults had entered a university and approximately two thirds were working during the month prior to the interview. Entry in the university was determined by economic conditions. Furthermore, women's birth weight and breastfeeding among men influenced this outcome. Insertion in the labor market was more frequent among the poorer men, but this did not affect women's outcomes in this respect.

CONCLUSIONS

The low inclusion in the university and the need to enter the labor market among the poor families maintains a vicious circle that reproduces the dominant social hierarchy.

Outcomes of conduct problems in adolescence: 40 year follow-up of national cohort

OBJECTIVE

To describe long term outcomes associated with externalising behaviour in adolescence, defined in this study as conduct problems reported by a teacher, in a population based sample.

DESIGN

Longitudinal study from age 13-53.

SETTING

The Medical Research Council National Survey of Health and Development (the British 1946 birth cohort).

PARTICIPANTS

3652 survey members assessed by their teachers for symptoms of externalising behaviour at age 13 and 15.

MAIN OUTCOME MEASURES

Mental disorder, alcohol abuse, relationship difficulties, highest level of education, social class, unemployment, and financial difficulties at ages 36-53.

RESULTS

348 adolescents were identified with severe externalising behaviour, 1051 with mild externalising behaviour, and 2253 with no externalising behaviour. All negative outcomes measured in adulthood were more common in those with severe or mild externalising behaviour in adolescence, as rated by teachers, compared with those with no externalising behaviour. Adolescents with severe externalising behaviour were more likely to leave school without any qualifications (65.2%; adjusted odds ratio 4.0, 95% confidence interval 2.9 to 5.5), as were those with mild externalising behaviour (52.2%; 2.3, 1.9 to 2.8), compared with those with no externalising behaviour (30.8%). On a composite measure of global adversity throughout adulthood that included mental health, family life and relationships, and educational and economic problems, those with severe externalising behaviour scored significantly higher (40.1% in top quarter), as did those with mild externalising behaviour (28.3%), compared with those with no externalising behaviour (17.0%).

CONCLUSIONS

Adolescents who exhibit externalising behaviour experience multiple social and health impairments that adversely affect them, their families, and society throughout adult life.

A twin study of cognitive costs of low birth weight and catch-up growth

OBJECTIVE

To investigate whether there is an association between catch-up growth and cognitive performance in humans.

STUDY DESIGN

Catch-up growth was defined as the change in weight standard deviation scores during the first 2 years of life. Cognitive performance was assessed with psychometric IQ tests, administered at ages 12 and 18 years. Data were collected in twin pairs, and analyses were carried out within pairs.

RESULTS

There was a significant negative association between catch-up growth and IQ at both ages 12 and 18 years.

CONCLUSIONS

A larger gain in weight during the first 2 years of life is associated with a lower IQ. However, catch-up growth is correlated with birth weight and this correlation may explain part of the association.

Evidence ν. rights-based decision making for nutrition

The need for an evidence base for human nutrition action is analysed in the context of human rights. Over the last 50 years the twin tracks of development, economical needs based and normative rights based, have come progressively closer in terms of goals and objectives, even if they do maintain different orientations and origins. The international human rights machinery is described, together with those parts that are of relevance to the right to food and nutrition. The role of the State in respecting, protecting and facilitating these rights is further described. The evidence base for the benefit of nutrition interventions during the fetal and infant period to the health and well-being of populations throughout life's course is briefly reviewed, and reasons why such a large body of evidence has not been acted upon are discussed. The power of nutrition is in prevention more than cure, and the prevention of nutritional deficiency is best suited to radical population-wide strategies rather than high-risk strategies targeted at individuals. The population-wide distribution of benefits of nutrition is in congruence with universality of human rights. In the UK much remains to be done to ensure that food and nutrition rights are realised, especially during the critical period of fetal and infant growth. What role the Nutrition Society might play in the realisation of these rights, including the creation of a robust evidence base for nutrition action, is further discussed.

How health status affects progress and performance in school: a population-based study

OBJECTIVE

To assess the effects of health status at birth and health status in the preschool years on educational outcomes to age 9 in a population-based birth cohort.

METHODS

Administrative data were used to follow all children born to Winnipeg mothers in 1990, and remaining in Manitoba until September 2004 (N = 5,873). A structural equation model was used, incorporating latent variables to represent Health Status at Birth, Major Illness and Minor Illness during the preschool years. The model also included the child's sex and exact age, along with a number of social, economic, and demographic characteristics of the child's family. The outcome was a combination of marks on Grade 3 Standards Tests and enrollment in the appropriate grade for age.

RESULTS

Major Illness in the preschool years had a significant influence on progress and performance in school (p = 0.0003), predicting 1.26% of the variation in the outcome. Minor Illness was weaker but still significant (p < 0.01). Health Status at Birth was not directly related to the outcome; its effect was mediated by Major and Minor Illness in childhood. Overall, the strongest predictors were the child's age and the area-level income, followed by the mother's age, family receipt of income assistance, the sex of the child, breastfeeding initiation (all p < 0.0001), and Major Illness.

CONCLUSIONS

Health status plays a statistically significant but substantively small role in explaining progress and performance in school among a population-based cohort. Major Illness was more important than Minor Illness, and these two factors completely mediated the influence of Health Status at Birth on the outcome. The strength of the social, economic, and demographic variables underscores the importance of the broader factors that affect both health and educational outcomes.

Factors associated with antidepressant, anxiolytic and hypnotic use over 17 years in a national cohort

BACKGROUND

In the general population, most individuals with mental disorders are not treated with psychotropic medications. The objective of this study was to identify factors associated with psychotropic medication use over a 17 year period in a birth cohort.

METHOD

Members of the 1946 British birth cohort (n=2,928 in 1999) reported psychotropic medication use in 1982 at age 36, in 1989 at age 43, and in 1999 at age 53. At each of the three time points, several factors were investigated for their association with antidepressant, anxiolytic or hypnotic medication use.

RESULTS

After adjusting for severity of symptoms of depression and anxiety, clinical factors such as suicidal ideation, sleep difficulty and poor physical health were strongly associated with antidepressant, anxiolytic or hypnotic medication use in 1982 and 1989, but not in 1999. Non-clinical factors were infrequently associated with antidepressant, anxiolytic or hypnotic medication use in 1982 and 1989 after adjusting for severity of symptoms, however several non-clinical factors were associated with antidepressant, anxiolytic or hypnotic medication use in 1999 including being female (OR=1.4, 95% CI: 1.0, 1.9), unemployment (OR=2.9, 95% CI: 2.1, 4.1), living alone (OR=2.6, 95% CI: 1.7, 3.9), and being divorced, separated or widowed (OR=1.5, 95% CI: 1.1, 2.3).

LIMITATIONS

Data were not available on help-seeking behaviour.

CONCLUSIONS

Treatment of mental disorder with psychotropic medications is strongly associated with clinical factors. However, non-clinical factors continue to be significant, and may influence both treatment-seeking and prescribing behaviour.

Prenatally undernourished rats show increased preference for wheel running v. lever pressing for food in a choice task

Maternal nutrition during pregnancy has a significant influence in establishing patterns of metabolism and postnatal behaviours in offspring, and therefore shapes their risk of developing disorders in later life. Although it is well established that a mismatch between food consumption and energy expenditure leads to obesity and metabolic dysregulation, little research has investigated the biological origin of such behaviour. We conducted the present experiments to investigate effects of early-life nutrition on preference between wheel running and lever pressing for food during adult life. To address this issue we employed a well-established experimental approach in the rat which has shown that offspring of mothers undernourished during pregnancy develop obesity and metabolic disorders when kept under standard laboratory conditions. Using this experimental approach, two studies were conducted where offspring of ad libitum-fed dams and dams undernourished throughout pregnancy were given the choice between wheel running and pressing a response lever for food. Across subsequent conditions, the rate at which the response lever provided food was varied from 0.22 to 6.0 (study 1) and 0.19 to 3.0 (study 2) pellets per min. Compared with the control group, offspring from dams undernourished during pregnancy showed a consistently greater preference for running over lever pressing for food throughout both experiments of the study. The results of the present study provide experimental evidence that a mother's nutrition during pregnancy can result in a long-term shift in her offspring's lifestyle choices that are relevant to obesity prevention. Such a shift, if endorsed, will have substantial and wide-ranging health consequences throughout the lifespan.

Infant growth and child cognition at 3 years of age

BACKGROUND

Infancy is a critical period for brain development. Few studies have examined the extent to which infant weight gain is associated with later neurodevelopmental outcomes in healthy populations.

OBJECTIVE

The purpose of this work was to examine associations of infant weight gain from birth to 6 months with child cognitive and visual-motor skills at 3 years of age.

PATIENTS AND METHODS

We studied 872 participants in Project Viva, an ongoing prospective, longitudinal, prebirth cohort. We abstracted birth weight from the medical chart and weighed infants at 6 months of age. We used the 2000 Centers for Disease Control and Prevention growth charts to derive weight-for-age z scores. Our primary predictor was infant weight gain, defined as the weight-for-age z score at 6 months adjusted for the weight-for-age z score at birth. At 3 years of age, we measured child cognition with the Peabody Picture Vocabulary Test III and visual-motor skills with the Wide Range Assessment of Visual Motor Abilities.

RESULTS

Mean Peabody Picture Vocabulary Test III score was 104.2, and mean Wide Range Assessment of Visual Motor Abilities test score was 102.8. Mean birth weight z score was 0.21, and mean 6-month weight z score was 0.39. In multiple linear regression adjusted for child age, gender, gestational age, breastfeeding duration, primary language, and race/ethnicity; maternal age, parity, smoking status, and cognition; and parental education and income level, we found no association of infant weight gain with child Peabody Picture Vocabulary Test III score (-0.4 points per z score weight gain increment, 95% confidence interval -1.3, 0.6) or total Wide Range Assessment of Visual Motor Abilities standard score (-0.4 points, 95% confidence interval -1.2, 0.5).

CONCLUSIONS

Slower infant weight gain was not associated with poorer neurodevelopmental outcomes in healthy, term-born 3-year-old children. These results should aid in determining optimal growth patterns in infants to balance risks and benefits of health outcomes through the life course.

Low birth weight, prematurity, and paternal social status: impact on the basic competence test in Taiwanese adolescents

OBJECTIVE

To investigate whether birth weight and paternal education may have independent and interactive effects on the learning achievement of adolescents.

STUDY DESIGN

We linked birth weights, gestational ages (term or preterm) and paternal education of a 4-year birth cohort to the Basic Competence Test (BCT) scores in Mandarin, mathematics and science for junior high school students age 15 to 16 years. The study groups comprised infants with term low birth weight (TLBW; n = 33 507), preterm normal birth weight (PNBW; n =19 905), and preterm low birth weight (PLBW; n = 25 840), as well as randomly selected term infants with normal birth weight (TNBW; n = 83 756). Paternal education levels were categorized.

RESULTS

Compared with the TNBW adolescents, the TLBW adolescents consistently showed larger deficits in mean scores for Mandarin (beta = -2.36), mathematics (beta = -2.89), and science (beta = -2.11). The corresponding significant deficit scores for the PLBW adolescents were -1.93, -2.80, and -1.92. The deficit scores were very small for the PNBW adolescents. Paternal education was inversely associated with scores of all 3 groups. Lower paternal education level tended to worsen the negative impact of low birth weight on BCT scores.

CONCLUSIONS

Both lower birth weight and lower paternal education exert an independent and interactive effect on adolescent learning achievement.

Body size at birth and socio-economic status in childhood: implications for Cloninger's psychobiological model of temperament at age 60

Small birth size predicts various psychiatric outcomes, including depression. While biologically based temperamental traits may constitute a vulnerability factor for depression, the extent to which birth size predicts these traits in adulthood is not known. We studied, in 1369 women and men identified from a cohort born in 1934-44 in Helsinki, Finland, whether birth size predicts the temperamental traits measured with Cloninger's Tridimensional Personality Questionnaire at an average age of 63 years. Moreover, we examined whether socio-economic status (SES) in childhood modified the associations. Data on birth size were obtained from birth records, and SES in childhood was obtained from school records. Weight and length at birth showed curvilinear, reverse J-shaped effects on harm avoidance (HA), such that the highest HA scores were most characteristic of those born small. Furthermore, high HA was confined to those belonging to a low SES group in childhood regardless of birth size, and to those belonging to the high SES group in childhood if their birth size was small. The associations were independent of several confounders. Since small birth size as well as high HA in adulthood may associate with subsequent depression, our findings might shed light on understanding the early neurodevelopmental processes that predispose to depression through vulnerability characteristics.