Prevalence of attention-deficit/hyperactivity disorder and autism in 12-year-old children: A population-based cohort

AIM

To investigate the prevalence of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in a population-based birth cohort and correlate the findings with prenatal and perinatal factors. We hypothesized that children born preterm, having experienced preeclampsia or maternal overweight, would have an increased risk of ADHD or ASD.

METHOD

A Swedish cohort of 2666 children (1350 males, 1316 females) has been followed from birth with parental and perinatal data. The National Board of Health and Welfare's registries were used to collect data regarding perinatal status and assigned diagnoses at the age of 12 years.

RESULTS

The prevalence of ADHD and ASD was 7.6% and 1.1% respectively. Maternal obesity early in pregnancy resulted in a three-fold increased risk of ADHD in the child. Similarly, paternal obesity resulted in a two-fold increased risk. The association was significant also when adjusted for sex, preterm birth, smoking, and lower educational level. The prevalence of ASD was too low for statistically relevant risk factor analyses.

INTERPRETATION

Our results corroborate earlier findings regarding prevalence and sex ratio for both ADHD and ASD. Maternal body mass index and preterm birth were correlated with an ADHD diagnosis at the age of 12 years.

Children's cognitive performance and suicide risk through middle adulthood

BACKGROUND

Longitudinal studies show that lower cognitive performance in adolescence and early adulthood is associated with higher risk of suicide death throughout adulthood. However, it is unclear whether this cognitive vulnerability originates earlier in childhood since studies conducted in children are scarce and have inconsistent results.

METHODS

Vital status of 49,853 individuals born between 1959 and 1966 to participants in the Collaborative Perinatal Project cohort was determined by a probabilistic linkage to the National Death Index, covering all US deaths occurring from 1979 through 2016. Cox proportional hazard models were used to examine associations of general, verbal, and non-verbal intelligence at ages 4 and 7, and academic skills at age 7 with suicide death coded according to ICD-9/10 criteria, while accounting for sociodemographic and pregnancy factors previously associated with suicide in this sample.

RESULTS

By the end of 2016, 288 cohort members had died by suicide. Cognitive performance at 7 years on tests with verbal components was associated with suicide risk (average vs. high verbal intelligence, HR = 1.97, 95% CI 1.05-3.71; low vs. high spelling skills, HR = 2.02, 95% CI 1.16-3.51; low vs. high reading skills, HR = 2.01, 95% CI 1.27-3.17). Associations were still evident, especially for verbal intelligence and reading skills, but hazard ratios were attenuated after adjusting for prenatal and sociodemographic factors at birth (verbal intelligence, HR = 1.97, 95% CI 1.03-3.78; spelling, HR = 1.61, 95% CI 0.90-2.88; reading, HR = 1.67, 95% CI 1.02-2.72).

CONCLUSIONS

Childhood neurocognitive performance is associated with vulnerability to suicide mortality through middle-adulthood, suggesting that there might be a cognitive diathesis for suicide originating in early childhood. Future studies should examine how multiple domains of childhood cognitive performance contribute to vulnerability to suicide risk, including by increasing risk for social and environmental factors that are associated not only with suicide but also with many types of psychiatric disorders.

Maternal Pre-Pregnancy Body Mass Index, Gestational Weight Gain and Children’s Cognitive Development: A Birth Cohort Study

To investigate the joint effect of maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) on children’s cognitive development. We recruited 1685 mother–child pairs from the Ma’anshan Birth Cohort in China. Pre-pregnancy BMI and GWG were calculated based on the height and weights measured at multiple antenatal checkups. Children’s cognition was assessed by Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition. Poisson regression model was used to analyze the association between maternal pre-pregnancy BMI and children’s cognitive dimensions under different GWG categories. Women with overweight or obese before pregnancy were more likely to obtain excessive GWG. When women had excessive GWG, pre-pregnancy overweight was associated with low children’s PSI (OR = 1.69, 95%CI: 1.02–2.81) and pre-pregnancy obesity was related to poor VCI in children (OR = 3.71, 95%CI: 1.49–9.22), after adjusting for potential confounders. In pre-pregnancy underweight mothers, adequate GWG reduced the risk of below-average VSI in children (OR = 0.22, 95%CI: 0.05–0.92), but excessive GWG was related to low FSIQ in children (OR = 2.53, 95%CI: 1.34–4.76). In women with excessive GWG, maternal pre-pregnancy BMI displays an inverted U-shape association with children’s cognition. Moreover, adequate GWG in women with pre-pregnancy underweight was beneficial for children’s cognition.

Maternal Cardiovascular Health in Early Pregnancy and Childhood Brain Structure

Background Poor cardiovascular health during pregnancy has been associated with adverse neurocognitive outcomes in the offspring. We examined the associations of maternal cardiovascular health factors with brain structure in 10-year-old children. Methods and Results We included 2797 mother-offspring pairs from the Generation R Study. Maternal body mass index, gestational weight gain, blood pressure, insulin, glucose, and lipid blood concentrations were obtained in early pregnancy. Childhood structural brain measures, including global metrics of brain tissue volumes and white matter microstructure, were quantified by magnetic resonance imaging at 10 years. As compared with offspring of mothers with normal weight, those of mothers with underweight had smaller total brain volume (difference, -28.99 [95% CI -56.55 to -1.45] cm³). Similarly, as compared with offspring of mothers with gestational weight gain between the 25th and 75th percentile, those of mothers with gestational weight loss or no gestational weight gain (<25th percentile), had smaller total brain volume (difference, -13.07 [95% CI, -23.82 to -2.32] cm³). Also, higher maternal diastolic blood pressure in early pregnancy was associated with lower offspring white matter mean diffusivity (difference, -0.07 [95% CI, -0.11 to -0.02] SD score). After multiple testing correction, only the association of maternal diastolic blood pressure with lower offspring white matter mean diffusivity remained statistically significant. No associations were observed of maternal insulin, glucose, and lipid concentrations with childhood brain outcomes. Conclusions Our findings suggest that maternal cardiovascular health during pregnancy might be related to offspring brain development in the long term. Future studies are needed to replicate our findings and to explore the causal nature of the associations.

Impact of Maternal Obesity on the Gestational Metabolome and Infant Metabolome, Brain, and Behavioral Development in Rhesus Macaques

Maternal gestational obesity is associated with elevated risks for neurodevelopmental disorder, including autism spectrum disorder. However, the mechanisms by which maternal adiposity influences fetal developmental programming remain to be elucidated. We aimed to understand the impact of maternal obesity on the metabolism of both pregnant mothers and their offspring, as well as on metabolic, brain, and behavioral development of offspring by utilizing metabolomics, protein, and behavioral assays in a non-human primate model. We found that maternal obesity was associated with elevated inflammation and significant alterations in metabolites of energy metabolism and one-carbon metabolism in maternal plasma and urine, as well as in the placenta. Infants that were born to obese mothers were significantly larger at birth compared to those that were born to lean mothers. Additionally, they exhibited significantly reduced novelty preference and significant alterations in their emotional response to stress situations. These changes coincided with differences in the phosphorylation of enzymes in the brain mTOR signaling pathway between infants that were born to obese and lean mothers and correlated with the concentration of maternal plasma betaine during pregnancy. In summary, gestational obesity significantly impacted the infant systemic and brain metabolome and adaptive behaviors.

Development of Spatial Orientation in Two-to-Three-Year-Old Children in Relation to Lifestyle Factors

Various lifestyle factors, including diet, physical activity, and sleep, have been studied in the context of children’s health. However, how these lifestyle factors contribute to the development of cognitive abilities, including spatial cognition, remains vastly understudied. One landmark in spatial cognitive development occurs between 2.5 and 3 years of age. For spatial orientation at that age, children learn to use allocentric reference frames (using spatial relations between objects as the primary reference frame) in addition to, the already acquired, egocentric reference frames (using one’s own body as the primary reference frame). In the current virtual reality study in a sample of 30–36-month-old toddlers (N = 57), we first demonstrated a marginally significant developmental shift in spatial orientation. Specifically, task performance with allocentric performance increased relative to egocentric performance (η_p² = 0.06). Next, we explored a variety of lifestyle factors, including diet, in relation to task performance, to explain individual differences. Screen time and gestational weight gain of the mother were negatively associated with spatial task performance. The findings presented here can be used to guide future confirmatory studies about the role of lifestyle factors in the development of spatial cognition.

Maternal Metabolic Programming of the Developing Central Nervous System: Unified Pathways to Metabolic and Psychiatric Disorders

The perinatal period presents a critical time in offspring development where environmental insults can have damaging impacts on the future health of the offspring. This can lead to sustained alterations in offspring development, metabolism, and predisposition to both metabolic and psychiatric diseases. The central nervous system is one of the most sensitive targets in response to maternal obesity and/or type 2 diabetes mellitus. While many of the effects of obesity on brain function in adults are known, we are only now beginning to understand the multitude of changes that occur in the brain during development on exposure to maternal overnutrition. Specifically, given recent links between maternal metabolic state and onset of neurodevelopmental diseases, the specific changes that are occurring in the offspring are even more relevant for the study of disease onset. It is therefore critical to understand the developmental effects of maternal obesity and/or type 2 diabetes mellitus and further to define the underlying cellular and molecular changes in the fetal brain. This review focuses on the current advancements in the study of maternal programming of brain development with particular emphasis on brain connectivity, specific regional effects, newly studied peripheral contributors, and key windows of interventions where maternal bodyweight and food intake may drive the most detrimental effects on the brain and associated metabolic and behavioral consequences.

Prepregnancy body mass index and gestational weight gain affect the offspring neurobehavioral development at one year of age

OBJECTIVE

Recent data show that maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) are associated with offspring neurobehavior in childhood. However, little is known about the effect on infants that less than 20 months of age, and whether this association has sex differences.

METHODS

In this birth cohort study, a total of 661 mother-infant pairs were enrolled in Shanghai, China, between February 2017 and April 2019. Maternal prepregnancy BMI was categorized according to the Chinese classification and GWG according to the 2009 Institute of Medicine (IOM). Neurobehavioral development for infants of 12 months of age was assessed by Gesell Developmental Scale (GDS), which contained five subscales of gross motor, fine motor, adaptive behavior, language, and social behavior.

RESULTS

Abnormal maternal prepregnancy BMI and excessive GWG were associated with infant birth weight and/or birth length (p < .05), while no influence was found on yearling weight or length. Women who were overweight/obese prior to pregnancy or excessive GWG during pregnancy had infants who were more deficient in neurobehavioral developmental including language (p < .01) and/or social behavior (p < .05). Specifically, excessive GWG was associated with lower language ability in girls but not boys (p < .05).

CONCLUSIONS

Aberrant prepregnancy BMI and excessive GWG not only affect the body size of newborn infants, but also impair their neurobehavioral development, suggesting that general guidance to the women should be advised to attain optimal prepregnancy BMI and GWG.

Pregnancy weight gain in twin gestations and maternal and child health outcomes at 5 years

Objective:

Current guidelines for maternal weight gain in twin pregnancy were established in the absence of evidence on its longer-term consequences for maternal and child health. We evaluated the association between weight gain in twin pregnancies and the risk of excess maternal postpartum weight increase, childhood obesity, and child cognitive ability.

Methods:

We used 5-year follow-up data from 1000 twins born to 450 mothers in the Early Childhood Longitudinal Study – Birth Cohort, a nationally representative U.S. cohort of births in 2001. Pregnancy weight gain was standardized into gestational age- and prepregnancy body mass index (BMI)-specific z-scores. Excess postpartum weight increase was defined as ≥10 kg increase from prepregnancy weight. We defined child overweight/obesity as BMI ≥ 85^th percentile, and low reading and math achievement as scores one standard deviation below the mean. We used survey-weighted multivariable modified Poisson models with a log link to relate gestational weight gain z-score with each outcome.

Results:

Excess postpartum weight increase occurred in 40% of mothers. Approximately 28% of twins were affected by overweight/obesity, and 16% and 14% had low reading and low math scores. There was a positive linear relationship between pregnancy weight gain and both excess postpartum weight increase and childhood overweight/obesity. Compared with a gestational weight gain z-score 0 SD (equivalent to 20 kg at 37 weeks gestation), a weight gain z-score of +1 SD (27 kg) was associated with 6.3 (0.71, 12) cases of excess weight increase per 1000 women and 4.5 (0.81, 8.2) excess cases of child overweight/obesity per 100 twins. Gestational weight gain was not related to kindergarten academic readiness.

Conclusions:

The high prevalence of excess postpartum weight increase and childhood overweight/obesity within the recommended ranges of gestational weight gain for twin pregnancies suggests that these guidelines could be inadvertently contributing to longer-term maternal and child obesity.

Understanding the Link Between Maternal Overnutrition, Cardio-Metabolic Dysfunction and Cognitive Aging

Obesity has long been identified as a global epidemic with major health implications such as diabetes and cardiovascular disease. Maternal overnutrition leads to significant health issues in industrial countries and is one of the risk factors for the development of obesity and related disorders in the progeny. The wide accessibility of junk food in recent years is one of the major causes of obesity, as it is low in nutrient content and usually high in salt, sugar, fat, and calories. An excess of nutrients during fetal life not only has immediate effects on the fetus, including increased growth and fat deposition in utero, but also has long-term health consequences. Based on human studies, it is difficult to discern between genetic and environmental contributions to the risk of disease in future generations. Consequently, animal models are essential for studying the impact of maternal overnutrition on the developing offspring. Recently, animal models provided some insight into the physiological mechanisms that underlie developmental programming. Most of the studies employed thus far have focused only on obesity and metabolic dysfunctions in the offspring. These studies have advanced our understanding of how maternal overnutrition in the form of high-fat diet exposure can lead to an increased risk of obesity in the offspring, but many questions remain open. How maternal overnutrition may increase the risk of developing brain pathology such as cognitive disabilities in the offspring and increase the risk to develop metabolic disorders later in life? Further, does maternal overnutrition exacerbate cognitive- and cardio-metabolic aging in the offspring?

Maternal high-fat diet during lactation reprograms the dopaminergic circuitry in mice

The maternal perinatal environment modulates brain formation, and altered maternal nutrition has been linked to the development of metabolic and psychiatric disorders in the offspring. Here, we showed that maternal high-fat diet (HFD) feeding during lactation in mice elicits long-lasting changes in gene expression in the offspring's dopaminergic circuitry. This translated into silencing of dopaminergic midbrain neurons, reduced connectivity to their downstream targets, and reduced stimulus-evoked dopamine (DA) release in the striatum. Despite the attenuated activity of DA midbrain neurons, offspring from mothers exposed to HFD feeding exhibited a sexually dimorphic expression of DA-related phenotypes, i.e., hyperlocomotion in males and increased intake of palatable food and sucrose in females. These phenotypes arose from concomitantly increased spontaneous activity of D1 medium spiny neurons (MSNs) and profoundly decreased D2 MSN projections. Overall, we have unraveled a fundamental restructuring of dopaminergic circuitries upon time-restricted altered maternal nutrition to induce persistent behavioral changes in the offspring.

Gestational weight gain and offspring's cognitive skills: a systematic review and meta-analysis

BACKGROUND

Gestational weight gain has been associated with some adverse perinatal outcomes, but few studies have examined the association between gestational weight gain and offspring's cognition and their conclusions are inconsistent. Our systematic review and meta-analysis aimed to synthesize the evidence regarding the association between gestational weight gain and offspring's cognitive skills.

METHODS

In this systematic review and meta-analysis (PROSPERO number, CRD42017073266), we systematically searched MEDLINE, EMBASE, Web of Science and the Cochrane Library for studies examining association between gestational weight gain and offspring's cognitive skills, without restriction in study design or language. Two reviewers extracted in an independent way the data. The Quality of Reporting of Observational Longitudinal Research scale was used to assess the quality of included studies. Effect size (ES) for adjusted models and their corresponding 95% confidence intervals were calculated for (i) intelligence quotient, (ii) language related skills and (iii) mathematic related skills comparing offspring's cognitive skills when gestational weight gain was within recommendations (as reference) with those from mothers whose gestational weight gain was above or below the recommendations.

RESULTS

Thirteen studies were included. There was a positive trend that associated gestational weight gain above recommendations with better offspring's intelligence quotient, although not statistically significant (ES 0.02, 95% CI -0.00, 0.05; I² = 0.00%).

CONCLUSIONS

There is a not significant positive association between gestational weight gain above recommendations and intelligence quotient and some studies reported associations between gestational weight gain and offspring's cognitive skills. Our analyses confirm a wide variability in the results of studies published so far and highlights the need for conducting studies including specific samples of pregnant women by pre-pregnancy body mass index and trimester of pregnancy.

Maternal excessive gestational weight gain as a risk factor for autism spectrum disorder in offspring: a systematic review

Background

Abnormal gestational weight gain (GWG) is a prenatal complication that may contribute to long-term behavioral and neurodevelopmental differences in offspring. This systematic review summarizes research on the association between maternal GWG and risk of autism spectrum disorder (ASD) in offspring.

Methods

Google and electronic databases, including PubMed, SCOPUS, Embase, Cochrane Library and Google Scholar, were searched for original human studies published in English through June 2020. Articles that examined the association between GWG and risk of ASD in offspring were included. Duplicate and irrelevant studies were removed; and data were obtained through critical analysis.

Results

Of 96 articles searched, eight studies were included in the final review. All studies (n = 7) investigating the association of maternal excessive GWG with risk of ASD in offspring indicated that high GWG was independently associated with an increased risk of ASD. Of five studies investigating the association of inadequate GWG with the risk of ASD, four indicated that low GWG was not associated with an increased risk of ASD. Of seven studies examining the association of maternal pre-pregnancy BMI or weight with the risk of ASD, five reported that maternal pre-pregnancy BMI or weight did not appear to be independently associated with risk of ASD. The GWG-ASD association is independent of maternal BMI and child’s intellectual disability, but offspring’s genetic susceptibility connection to the GWG-ASD association remains a topic of debate.

Conclusions

The findings suggest that maternal excessive GWG may be associated with increased risk of ASD in offspring. However, insufficient GWG does not appear to have such association.

Poor maternal nutritional status before and during pregnancy is associated with suspected child developmental delay in 2-year old Brazilian children

Inadequate pre-pregnancy BMI and gestational weight gain (GWG) have been associated with sub-optimal child development. We used data from the 2015 Pelotas (Brazil) Birth Cohort Study. Maternal anthropometry was extracted from antenatal/hospital records. BMI (kg/m2) and GWG (kg) adequacy were classified according to WHO and IOM, respectively. Development was evaluated using the INTER-NDA assessment tool for 3,776 children aged 24 months. Suspected developmental delay (SDD) was defined as <10th percentile. Associations between maternal exposures and child development were tested using linear and logistic regressions. Mediation for the association between BMI and child development through GWG was tested using G-formula. Sex differences were observed for all child development domains, except motor. Maternal pre-pregnancy underweight increased the odds of SDD in language (OR: 2.75; 95%CI: 1.30-5.80), motor (OR: 2.28; 95%CI: 1.20-4.33), and global (OR: 2.14; 95% CI: 1.05-4.33) domains for girls; among boys, excessive GWG was associated with SDD in language (OR: 1.59; 95%CI: 1.13-2.24) and cognition (OR: 1.59; 95%CI: 1.15-2.22). Total GWG suppressed the association of pre-pregnancy BMI with percentiles of global development in the entire sample. Maternal underweight and excessive GWG were negatively associated with development of girls and boys, respectively. The association of pre-pregnancy BMI with global child development was not mediated by GWG, irrespective of child's sex.

Effect of maternal pre-pregnancy underweight and average gestational weight gain on physical growth and intellectual development of early school-aged children

The aim of this study was to assess the effect of low maternal weight at pre-pregnancy and the average gestational weight gain on undernourished children and their intellectual development. From October 2012 to September 2013, we followed 1744 offspring of women who participated in a trial conducted from 2002 to 2006. Pregnant women recruited in the original trial could receive three prenatal health checks for free, at which maternal weight and height were measured. WISC-IV was used to estimate the intellectual development of children. Weight and height of both pregnant women and children were measured by trained anthropometrists using standard procedures. Having low maternal weight at pre-pregnancy was associated with an increased risk of undernutrition amongst children (underweight: OR = 2.02, 95%CI: 1.14-3.56, thinness: OR = 2.79, 95%CI: 1.50-5.17) and a decrease in verbal comprehension index (-2.70 points, 95%CI: -4.95-0.44) of children. The effect of average gestational weight gain on occurrences of underweight children (OR = 0.08, 95%CI: 0.01-0.55) was also found. We identified the effect of maternal pre-pregnancy underweight on impairment of the separate intellectual domains (verbal comprehension index) and increasing occurrence of undernourished children. Average gestational weight gain was positively associated with a decreased prevalence of underweight children but not with the intellectual development of children in rural China.

Adiposity and weight gain during pregnancy associate independently with behavior of infant rhesus monkeys (Macaca mulatta)

Growing evidence identifies maternal adiposity as a potentially modifiable risk factor for adverse neurodevelopment. This retrospective cohort analysis examined whether maternal prepregnancy adiposity and gestational weight gain were associated with behavioral outcomes in 173 rhesus macaque infants at the California National Primate Research Center. Dams conceived indoors, had uncomplicated pregnancies, delivered vaginally, and reared infants indoors. Infants underwent standardized biobehavioral analysis at 90-120 days of age from 3/2001-5/2015. Offspring of mothers with greater baseline adiposity or gestational weight gain exhibited a pattern of poor adaptability characterized by greater emotionality as the assessments proceeded, blunted affective response to a human intruder challenge, and reduced interest in novel stimuli which is associated with poorer social functioning later in life. They also had lower cortisol levels following dexamethasone suppression, perhaps a response to cortisol excess during gestation. These results amplify growing public health concerns implicating maternal adiposity in impaired fetal neurobehavioral programming.

Prepregnancy overweight and obesity are associated with impaired child neurodevelopment

The authors examined the relationship of prepregnancy body mass index (BMI) and gestational weight gain (GWG) with child neurodevelopment. Mother-child dyads were a subgroup (n = 2,084) of the Child Health and Development Studies from the Oakland, California, area enrolled during pregnancy from 1959 to 1966 and followed at child age 9 years. Linear regression was used to examine associations between prepregnancy BMI, GWG, and standardized Peabody Picture Vocabulary Test and Raven Progressive Matrices scores and to evaluate effect modification of GWG by prepregnancy BMI. Before pregnancy, 77% of women were normal weight, 8% were underweight, 11% were overweight, and 3% were obese. Associations between GWG and child outcomes did not vary by prepregnancy BMI, suggesting no evidence for interaction. In multivariable models, compared to normal prepregnancy BMI, prepregnancy overweight and obesity were associated with lower Peabody scores (b: -1.29; 95% CI [-2.6, -0.04] and b: -2.7; 95% CI [-5.0, -0.32], respectively). GWG was not associated with child Peabody score [b: -0.03 (95% CI: -0.13, 0.07)]. Maternal BMI and GWG were not associated with child Raven score (all P >0.05). Maternal prepregnancy overweight and obesity were associated with lower scores for verbal recognition in mid-childhood. These results contribute to evidence linking maternal BMI with child neurodevelopment. Future research should examine the role of higher prepregnancy BMI values and the pattern of pregnancy weight gain in child cognitive outcomes.

Maternal pre-pregnancy obesity and gestational weight gain influence neonatal neurobehaviour

Maternal weight before and during pregnancy is associated with offspring neurobehaviour in childhood. We investigated maternal weight prior to and during pregnancy in relation to neonatal neurobehaviour. We hypothesized that maternal obesity and excessive gestational weight gain would be associated with poor neonatal attention and affective functioning. Participants (n = 261) were recruited, weighed and interviewed during their third trimester of pregnancy. Pre-pregnancy weight was self-reported and validated for 210 participants, with robust agreement with medical chart review (r = 0.99). Neurobehaviour was measured with the NICU Network Neurobehavioural Scale (NNNS) administered on Days 2 and 32 postpartum. Maternal exclusion criteria included severe or persistent physical or mental health conditions (e.g. chronic disease or diagnoses of Bipolar Disorder or Psychotic Spectrum Disorders), excessive substance use, and social service/foster care involvement or difficulty understanding English. Infants were from singleton, full-term (37-42 weeks gestation) births with no major medical concerns. Outcome variables were summary scores on the NNNS (n = 75-86). For women obese prior to pregnancy, those gaining in excess of Institute of Medicine guidelines had infants with poorer regulation, lower arousal and higher lethargy. There were no main effects of maternal pre-pregnancy body mass index on neurobehaviour. Women gaining above Institute of Medicine recommendations had neonates with better quality of movement. Additional studies to replicate and extend results past the neonatal period are needed. Results could support underlying mechanisms explaining associations between maternal perinatal weight and offspring outcomes. These mechanisms may inform future prevention/intervention strategies. © 2016 Blackwell Publishing Ltd.

Trajectories of maternal gestational weight gain and child cognition assessed at 5 years of age in a prospective cohort study

BACKGROUND

There has been concern that low gestational weight gain may cause poor fetal neurodevelopment.

METHODS

The association between maternal weight gain and child IQ was examined using serial antenatal weight measurements (median 12) from a prospective cohort of non-obese Scandinavian women (1986-1988). Linear mixed models with piecewise regression were used to estimate participants' (n=552) trimester-specific average rate of weight gain. Linear regression was used to assess the association between weight gain and children's (n=344) full-scale, performance and verbal IQ measured at age 5 using the Wechsler Preschool and Primary Scales of Intelligence-Revised.

RESULTS

Children born to mothers who gained below versus within the 2nd trimester 2009 recommendations tended to have lower IQ scores (Full-scale: 106.6 (SD 15.1) vs 110.2 (15.2), p=0.04; verbal: 102.5 (14.3) vs 105.0 (14.9), p=0.10; performance: 109.5 (15.4) vs 113.4 (14.5), p=0.03). After adjustment there were no differences in child IQ by weight gain adequacy (full-scale: βbelow=-1.1 (95% CI -5.1 to 2.9), βabove=1.5 (-3.8 to 6.8); verbal: βbelow=-0.2 (-3.1 to 2.6), βabove=1.8 (-3.6 to 7.3); performance βbelow=-1.2 (-4.6 to 2.2), βabove=1.0 (-4.6 to 6.7)). No differences were observed based on 3rd trimester adequacy. No differences were observed in IQ scores by quintile of weight gain for any trimester, particularly after adjustment for maternal IQ.

CONCLUSIONS

Our findings are reassuring that among normal weight women, pregnancy weight gain is not associated with child cognitive development. Further investigation should be conducted in contemporary cohorts that also include obese mothers, who are at the greatest risk for low weight gain.

Child academic achievement in association with pre-pregnancy obesity and gestational weight gain

BACKGROUND

Recent data suggest that children of mothers who are obese before pregnancy, or who gain too much weight during pregnancy, may be at an increased risk of cognitive impairments.

METHODS

Mother-infant dyads enrolled in a birth cohort study in Pittsburgh, Pennsylvania (1983-1986), were followed from early pregnancy to 14 years postpartum (n=574). Math, reading and spelling achievements were assessed at ages 6 and 10 years using the Wide Range Achievement Test-Revised, and at age 14 years using the Wechsler Individual Achievement Test Screener. Self-reported total GWG was converted to gestational age-standardised z-scores. Generalised estimating equations were used to estimate the effects of GWG and pre-pregnancy body mass index (BMI) on academic achievement at 6, 10 and 14 years, while adjusting for maternal race, child sex, parity, employment, family income, maternal intelligence, maternal depression, pre-pregnancy BMI (in GWG models only) and the home environment.

RESULTS

The mean (SD) BMI was 23.4 (5.7) kg/m(2) and the mean (SD) GWG reported at delivery was 14.4 (5.9) kg. There was a significant non-linear association between pre-pregnancy BMI and an offspring's academic achievement. At 6, 10 and 14 years, an offspring's academic scores were inversely associated with pre-pregnancy BMI beyond 22 kg/m(2). High GWG (>1 SD) was associated with approximately 4-point lower reading (adjusted β (adjβ) -3.75, 95% CI -7.1 to -0.4) and spelling scores (adjβ -3.90, 95% CI -7.8 to -0.2), compared with GWG -1 to +1 SD.

CONCLUSIONS

Future studies in larger and socioeconomically diverse populations are needed to confirm maternal weight and weight gain as causal determinants of a child's academic skills, and whether this effect persists into adulthood.

Maternal Obesity and Excessive Gestational Weight Gain Are Associated with Components of Child Cognition

BACKGROUND

Maternal overweight and obesity affect two-thirds of women of childbearing age and may increase the risk of impaired child cognition.

OBJECTIVE

Our objective was to test the hypothesis that high/low gestational weight gain (GWG) and high/low prepregnancy BMI were associated with offspring intelligence quotient (IQ) and executive function at age 10.

METHODS

Mother-infant dyads (n = 763) enrolled in a birth cohort study were followed from early pregnancy to 10 y postpartum. IQ was assessed by trained examiners with the use of the Stanford Binet Intelligence Scale-4th edition. Executive function was assessed by the number of perseverative errors on the Wisconsin Card Sorting Test and time to complete Part B on the Trail Making Test. Self-reported total GWG was converted to gestational-age-standardized GWG z score. Multivariable linear regression and negative binomial regression were used to estimate independent and joint effects of GWG and BMI on outcomes while adjusting for covariates.

RESULTS

At enrollment, the majority of women in the Maternal Health Practices and Child Development cohort were unmarried and unemployed, and more than one-half reported their race as black. The mean ± SD GWG z score was -0.5 ± 1.8, and 27% of women had a pregravid BMI ≥ 25. The median (IQR) number of perseverative errors was 23 (17, 29), the mean ± SD time on Part B was 103 ± 42.6 s, and 44% of children had a low average IQ (≤ 89). Maternal obesity was associated with 3.2 lower IQ points (95% CI: -5.6, -0.8) and a slower time to complete the executive function scale Part B (adjusted β: 12.7 s; 95% CI: 2.8, 23 s) compared with offspring of normal-weight mothers. Offspring of mothers whose GWG was >+1 SD, compared with -1 to +1 SD, performed 15 s slower on the executive function task (95% CI: 1.8, 28 s). There was no association between GWG z score and offspring composite IQ score (adjusted β: -0.32; 95% CI: -0.72, 0.10). Prepregnancy BMI did not modify these associations.

CONCLUSIONS

Although GWG may be important for executive function, maternal BMI has a stronger relation than GWG to both offspring intelligence and executive function. Our findings contribute to evidence linking maternal obesity to long-term child outcomes.

Gestational Weight Gain and Overweight in Children Aged 3-6 Years

Objective

To determine whether gestational weight gain (GWG) was associated with increased odds of childhood overweight after accounting for pre-pregnancy BMI.

Methods

In a prospective cohort study based on a premarital and perinatal health care system in China, data of 100 612 mother-child pairs were obtained. The main exposure was GWG as both a continuous and categorical variable. The outcome measure was overweight, defined by age- and sex-specific cutoff values for body mass index (BMI) in children aged 3–6 years.

Results

A 1-kg increase in maternal GWG was associated with an increase of 0.009 (95% confidence interval [CI]: 0.007–0.010, P < 0.001) in children’s mean BMI; in the subgroup of pre-pregnancy overweight/obese mothers, the increase in children’s BMI was 0.028 (95% CI, 0.017–0.039, P < 0.001). Excessive GWG played an important role in childhood overweight when adequate GWG was used as the reference, with an odds ratio (OR) of 1.21 (95% CI, 1.12–1.29). The risk was highest (OR 2.22; 95% CI, 1.79–2.76) in the children of mothers who were overweight/obese before pregnancy and gained excessive weight during pregnancy.

Conclusions

Greater maternal GWG was associated with greater offspring BMI, and the risk of overweight was doubled in children whose mothers were overweight/obese before pregnancy and gained excessive weight during pregnancy. As a result, maintenance of appropriate weight gain during pregnancy and prophylaxis of maternal overweight/obesity before pregnancy should be a strategy for preventing childhood overweight/obesity.

Maternal prepregnancy body mass index and child psychosocial development at 6 years of age

BACKGROUND

Both obesity and developmental disabilities have increased in recent decades. Limited studies suggest associations between maternal prepregnancy obesity and child neurodevelopment.

METHODS

The Infant Feeding Practices Study II, a US nationally distributed longitudinal study of maternal health and infant health and feeding practices, was conducted from 2005 to 2007. In 2012, mothers were recontacted for information on their children's health and development. We examined associations between maternal prepregnancy BMI and child psychosocial development in 1311 mother-child pairs included in this follow-up study. Children's development was assessed by maternal report of child psychosocial difficulties from the Strengths and Difficulties Questionnaire, past developmental diagnoses, and receipt of special needs services.

RESULTS

Adjusting for sociodemographic factors, children of obese class II/III mothers (BMI >35.0) had increased odds of emotional symptoms (adjusted odds ratio [aOR] 2.24; 95% confidence interval [CI], 1.27-3.98), peer problems (aOR 2.07; 95% CI, 1.26-3.40), total psychosocial difficulties (aOR 2.17; 95% CI, 1.24-3.77), attention-deficit/hyperactivity disorder diagnosis (aOR 4.55; 95% CI, 1.80-11.46), autism or developmental delay diagnosis (aOR 3.13; 95% CI, 1.10-8.94), receipt of speech language therapy (aOR 1.93; 95% CI, 1.18-3.15), receipt of psychological services (aOR 2.27; 95% CI, 1.09-4.73), and receipt of any special needs service (aOR 1.99; 95% CI, 1.33-2.97) compared with children of normal weight mothers (BMI 18.5-24.9). Adjustment for potential causal pathway factors including pregnancy weight gain, gestational diabetes, breastfeeding duration, postpartum depression, and child's birth weight did not substantially affect most estimates.

CONCLUSIONS

Children whose mothers were severely obese before pregnancy had increased risk for adverse developmental outcomes.

Maternal prepregnancy obesity and child neurodevelopment in the Collaborative Perinatal Project

OBJECTIVES

To examine the association between maternal prepregnancy weight and child neurodevelopment, and the effect of gestational weight gain.

METHODS

Using the U.S. Collaborative Perinatal Project data, 1959-76, a total of 30,212 women with a calculable prepregnancy body mass index (BMI) and gestational weight gain, and term singleton children followed up for more than 7 years were included in this study. Intelligence quotient (IQ) was measured at 7 years of age by Wechsler Intelligence Scales.

RESULTS

Maternal prepregnancy BMI displayed inverted U-shaped associations with child IQ after adjustment for maternal age, maternal education levels, maternal race, marital status, socioeconomic status, smoking during pregnancy, parity and study center. Women with BMI at around 20 kg/m2 appeared to have the highest offspring IQ scores. After controlling for familial factors in the siblings' sample, maternal obesity (BMI≥30.0 kg/m2) was associated with lower Full-scale IQ (adjusted ß=-2.0, 95% confidence interval -3.5 to -0.5), and Verbal scale IQ (adjusted ß=-2.5, 95% confidence interval -4.0 to -1.0), using BMI of 18.5-24.9 kg/m2 as the reference category. Compared with children born to normal-weight women who gained 21-25 lb. during pregnancy, those born to obese women who gained more than 40 lb. had 6.5 points deficit in IQ after adjustment for potential confounders.

CONCLUSIONS

Maternal prepregnancy obesity was associated with lower child IQ, and excessive weight gain accelerated the association. With obesity rising steadily, these results appear to raise serious public health concerns.

Maternal prepregnancy weight status and associations with children's development and disabilities at kindergarten

OBJECTIVE

Obesity is prevalent among women of reproductive age, and developmental disabilities in children continue to increase. We examined associations between mother's prepregnancy body mass index (BMI) and physical and developmental disabilities, and objective measures of reading and math skills and fine and gross motor function in children.

METHODS

We used the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B; n=5200), a cohort of children born in 2001 and followed until kindergarten. Children were classified according to maternal prepregnancy BMI (in kg per m(2)): underweight (BMI <18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9), obese class I (BMI 30.0-34.9) and obese class II/III (BMI ≥ 35.0). Parent reports of doctor-diagnosed disabilities were collected up to kindergarten and classified as learning and behavioral or physical. Children's reading and math and fine and gross motor function were assessed at kindergarten according to standardized tests. Linear and modified logistic regression models were adjusted for maternal sociodemographic variables, family enrichment variables, and children's sex, age and year of kindergarten entry. Additional adjustment for current child BMI was performed in separate models. All data are weighted to be nationally representative of the children born in 2001.

RESULTS

Compared with children of normal-weight mothers, children born to obese class II/III mothers had an increased risk of learning or behavioral (risk ratio 1.67; 95% confidence interval 1.27, 2.21)), but not physical disabilities (risk ratio 0.57; 95% confidence interval 0.27, 1.22). Gross (P<0.001), but not fine (P=0.06) motor function was significantly associated with maternal BMI, but gross motor function was attenuated after adjustment for current child BMI (P=0.05). Children's reading scores (P=0.01) but not math scores (P=0.11) were significantly associated with maternal BMI.

CONCLUSIONS

In this nationally representative US cohort, children born to severely obese mothers had an increased risk for diagnosed learning and behavioral but not physical disabilities by kindergarten.