Postnatal Year Research Articles

Association between Early Life Exposure to Air Pollution and Working Memory and Attention.

Background:Although previous studies have reported negative associations between exposure to air pollution and cognition, studies of the effects of prenatal and postnatal exposures in early childhood have been limited.Objectives:We sought to assess the role exposure to fine particulate matter () during different prenatal and postnatal windows may play in children’s cognitive development at school age.Methods:Within the Brain Development and Air Pollution Ultrafine Particles in School Children (BREATHE) Project, we estimated residential exposures by land use regression for the prenatal period and first seven postnatal years of 2,221 children from Barcelona, Spain. The participants () completed computerized tests assessing working memory, attentiveness, and conflict network during four visits in 2012–2013. We used linear mixed effects and distributed lag models to assess the period of exposure to in association with cognitive development.Results:Inverse associations were identified between exposure during the fifth and sixth postnatal years and working memory, with boys showing much higher vulnerability. Regarding attention functions, exposure to higher levels during the prenatal period and from the fourth postnatal year were associated with a reduction in conflict network performance, though we found no association with attentiveness. The overall estimated cumulative effect of a increase in resulted in a reduction in the working memory score of [95% confidence interval (CI): , ] points and an increase in the conflict attentional network of 11.31 (95% CI: 6.05, 16.57) milliseconds, indicating a poorer performance.Conclusions:Early life exposure to was associated with a reduction in fundamental cognitive abilities, including working memory and conflict attentional network. https://doi.org/10.1289/EHP3169

Modeling infants' perceptual narrowing to musical rhythms: neural oscillation and Hebbian plasticity.

Previous research suggests that infants' perception of musical rhythm is fine-tuned to culture-specific rhythmic structures over the first postnatal year of human life. To date, however, little is known about the neurobiological principles that may underlie this process. In the current study, we used a dynamical systems model featuring neural oscillation and Hebbian plasticity to simulate infants' perceptual learning of culture-specific musical rhythms. First, we demonstrate that oscillatory activity in an untrained network reflects the rhythmic structure of either a Western or a Balkan training rhythm in a veridical fashion. Next, during a period of unsupervised learning, we show that the network learns the rhythmic structure of either a Western or a Balkan training rhythm through the self-organization of network connections. Finally, we demonstrate that the learned connections affect the networks' response to violations to the metrical structure of native and nonnative rhythms, a pattern of findings that mirrors the behavioral data on infants' perceptual narrowing to musical rhythms.

Frequency of Depression and Risk Factors among Adolescent Mothers in Turkey within the First Year of the Postnatal Period.

Postpartum depression (PPD) emerges within the first 4weeks of the postnatal period and might continue for as long as 1year. The aims of this prospective study were to examine the prevalence, severity, and risk factors for PPD among adolescent mothers in Turkey. The study consisted of 84 adolescent mothers between the ages of 15 and 19years. The participants were questioned about PPD at 3 postnatal periods: 4weeks, 6months, and 1year. A 23-item question form, prepared to evaluate the risk of PPD, and the Edinburgh Postnatal Depression Scale were used. The risk of adolescent PPD was 19 (22.6%). There was a statistically significant association between the risk of PPD and various factors, such as age, educational background, trouble with partner and family, problems with sexual intercourse in the postnatal term, and assertiveness in making decisions about children (P<.05). At the 6-month follow-up, the scores of the Edinburgh Postnatal Depression Scale risk group remained the same, but they were lower at the 1-year follow-up. The results revealed that adolescent mothers need the assistance of partners, families, midwives/nurses, and other support systems, especially during the first postnatal year, to reduce the prevalence of adolescent PPD.

Brain size growth in Australopithecus

Postnatal growth is one of the proximate means by which humans attain massive adult brain size. Humans are characterized by the maintenance of prenatal brain growth rates into the first postnatal year, as well as an overall extended period of growth. The evolution of this pattern is difficult to assess due to its relatively brief duration and the underrepresentation of well-preserved fossil individuals who died during this short period. In this study, I use Monte Carlo methods to reconstruct postnatal brain growth rates in Australopithecus afarensis and Australopithecus africanus, based on estimates of neonatal brain size and of likely brain size and age at death of infant specimens (A.L. 333-105, DIK-1-1, and Taung). Neonatal brain size is reconstructed from the empirical scaling relationship among catarrhines which humans follow, and conservative estimates of fossils' chronological ages and brain sizes are drawn from the literature. Simulated distributions of these values are used to calculate average annual rates (ARs) of brain growth and proportional size change from birth (PSC), which are compared to resampled statistics from humans, chimpanzees and gorillas of known age and sex. Simulated ARs and PSCs for A. afarensis are significantly lower than those of chimpanzees and gorillas. Both ARs and PSCs for A. africanus are similar to chimpanzee and gorilla values. These results indicate that although these early hominins were derived in some aspects of brain anatomy, high rates of brain growth did not appear until later in human evolution. Moreover, findings also imply that brain growth rates are not a simple function of adult brain size. This study provides important new information about the evolution of brain growth, despite limitations inherent in fossil samples.

Evidence that prenatal testosterone transfer from male twins reduces the fertility and socioeconomic success of their female co-twins

During sensitive periods in utero, gonadal steroids help organize biological sex differences in humans and other mammals. In litter-bearing species, chromosomal females passively exposed to prenatal testosterone from male littermates exhibit altered physical and behavioral traits as adults. The consequences of such effects are less well understood in humans, but recent near-doubling of twinning rates in many countries since 1980, secondary to advanced maternal age and increased reliance on in vitro fertilization, means that an increasing subset of females in many populations may be exposed to prenatal testosterone from their male co-twin. Here we use data on all births in Norway (n = 728,842, including 13,800 twins) between 1967 and 1978 to show that females exposed in utero to a male co-twin have a decreased probability of graduating from high school (15.2%), completing college (3.9%), and being married (11.7%), and have lower fertility (5.8%) and life-cycle earnings (8.6%). These relationships remain unchanged among the subsets of 583 and 239 females whose male co-twin died during the first postnatal year and first 28 days of life, respectively, supporting the interpretation that they are due primarily to prenatal exposure rather than to postnatal socialization effects of being raised with a male sibling. Our findings provide empirical evidence, using objectively measured nation-level data, that human females exposed prenatally to a male co-twin experience long-term changes in marriage, fertility, and human capital. These findings support the hypothesis of in utero testosterone transfer between twins, which is likely affecting a small but growing subset of females worldwide.

Social complexity and the early social environment affect visual social attention to faces.

Diminished attention to socially relevant information appears to be an early emerging risk factor associated with autism spectrum disorders (ASD). However, inconsistencies across studies suggest that atypicalities in visual social attention in infants at high-risk for ASD during the first postnatal year may be subtle and more apparent under certain contexts. Here we explore factors that may moderate developmental trajectories in attention to faces, including the social complexity of the dynamic visual stimuli used to measure visual social attention and the early social environment of the infant as indexed by parental affectedness of ASD-related traits. Across infants at both high (HR) and low risk for ASD, attention to faces increased during the first postnatal year, with overall greater attention being allocated to schematic faces in the simpler video stimulus. Moreover, greater parental affectedness of ASD-related traits was associated with reduced developmental gains in attention to faces. For HR infants, greater attention to faces was positively associated with social communicative competence, including better joint attention skills and lower social impairments. Altogether, our findings highlight the importance of considering developmental level when selecting stimuli to longitudinally examine visual social attention, and the clinical relevance of including measures of infant's social environment in understanding early markers of ASD risk. Autism Res 2019, 12: 445-457 © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Attention to faces is an important means for infants to learn about the social world. The complexity of the social scene and an infant's early social environment both affect the amount of time infants at high- and low-risk for ASD look at faces during the first postnatal year. For infants at high-risk for ASD, greater attention to faces was associated with better social skills. Understanding an infant's social environment may have a positive impact on social communicative development.

Ambient ozone and fine particulate matter exposures and autism spectrum disorder in metropolitan Cincinnati, Ohio

BackgroundEpidemiological studies report fairly consistent associations between various air pollution metrics and autism spectrum disorder (ASD), with some elevated risks reported for different prenatal and postnatal periods. ObjectivesTo examine associations between ASD and ambient fine particulate matter (PM2.5) and ozone concentrations during the prenatal period through the second year of life in a case-control study. MethodsASD cases (n = 428) diagnosed at Cincinnati Children's Hospital Medical Center were frequency matched (15:1) to 6420 controls from Ohio birth records. We assigned daily PM2.5 and ozone estimates for 2005–2012 from US EPA's Fused Air Quality Surface Using Downscaling model to each participant for each day based on the mother's census tract of residence at birth. We calculated adjusted odds ratios (aORs) using logistic regression across continuous and categorical exposure window averages (trimesters, first and second postnatal years, and cumulative measure), adjusting for maternal- and birth-related confounders, both air pollutants, and multiple temporal exposure windows. ResultsWe detected elevated aORs for PM2.5 during the 2nd trimester, 1st year of life, and a cumulative period from pregnancy through the 2nd year (aOR ranges across categories: 1.41–1.44, 1.54–1.84, and 1.41–1.52 respectively), and for ozone in the 2nd year of life (aOR range across categories: 1.29–1.42). Per each change in IQR, we observed elevated aORs for ozone in the 3rd trimester, 1st and 2nd years of life, and the cumulative period (aOR range: 1.19–1.27) and for PM2.5 in the 2nd trimester, 1st year of life, and the cumulative period (aOR range: 1.11–1.17). DiscussionWe saw limited evidence of linear exposure-response relationships for ASD with increasing air pollution, but the elevated aORs detected for PM2.5 in upper exposure categories and per IQR unit increases were similar in magnitude to those reported in previous studies, especially for postnatal exposures.

Initiation of antiretroviral therapy after the critical neuronal developmental period of the second postnatal year affects white matter microstructure in adolescents living with HIV.

Rapid maturation of major white matter pathways occurs in the first 2years of life, indicating a critical neuronal developmental period. The impact of initiating antiretroviral therapy (ART) in children perinatally infected with HIV-1, after the age of 2years on neurocognitive functioning and white matter development in adolescence has not been studied. Forty-six adolescents who initiated ART during the first 2years of life (< 2years) and 79 adolescents who initiated ART after 2years of age (> 2years), with perinatally acquired HIV were enrolled in the Cape Town Adolescent Antiretroviral Cohort. Adolescents completed a comprehensive neurocognitive battery testing a number of cognitive domains. Diffusion tensor imaging (DTI) was done to determine fractional anisotropy (FA), mean diffusivity (MD), axial diffusion (AD), and radial diffusion (RD) in a region of interest analysis. Neurocognitive performance was similar between adolescents who initiated ART < 2years or > 2years. There was a trend towards attention (p= .07) and working memory (p= .05) being poorer in the group who initiated ART > 2years. FA was lower in the > 2-year group in the superior corona radiata (p= .03), and the external capsule (p= .04). MD was higher in the > 2-year group in the cerebral peduncle (p= .02), the superior corona radiata (p= .01), and the superior fronto-occipital fasciculus (p= .03). RD was higher in the > 2-year group in the superior corona radiata (p= .02), the cerebral peduncle (p= .01), and the superior fronto-occipital fasciculus (p= .01). However, the higher AD in the > 2-year group in the superior corona radiata was not in the expected direction (p= .01). Initiation of ART after the neuronal development period of the second postnatal year is associated with white matter alterations on neuroimaging.

Revealing Developmental Regionalization of Infant Cerebral Cortex Based on Multiple Cortical Properties.

The human brain develops dynamically and regionally heterogeneously during the first two postnatal years. Cortical developmental regionalization, i.e., the landscape of cortical heterogeneity in development, reflects the organization of underlying microstructures, which are closely related to the functional principles of the cortex. Therefore, prospecting early cortical developmental regionalization can provide neurobiologically meaningful units for precise region localization, which will advance our understanding on brain development in this critical period. However, due to the absence of dedicated computational tools and large-scale datasets, our knowledge on early cortical developmental regionalization still remains intact. To fill both the methodological and knowledge gaps, we propose to explore the cortical developmental regionalization using a novel method based on nonnegative matrix factorization (NMF), due to its ability in analyzing complex high-dimensional data by representing data using several bases in a data-driven way. Specifically, a novel multi-view NMF (MV-NMF) method is proposed, in which multiple distinct and complementary cortical properties (i.e., multiple views) are jointly considered to provide comprehensive observation of cortical regionalization process. To ensure the sparsity of the discovered regions, an orthogonal constraint defined in Stiefel manifold is imposed in our MV-NMF method. Meanwhile, a graph-induced constraint is also included to improve the compactness of the discovered regions. Capitalizing on an unprecedentedly large dataset with 1,560 longitudinal MRI scans from 887 infants, we delineate the first neurobiologically meaningful representation of early cortical regionalization, providing a valuable reference for brain development studies.

Policy Impacts of the Australian National Perinatal Depression Initiative: Psychiatric Admission in the First Postnatal Year

This paper helps to quantify the impact of the Australian National Perinatal Depression Initiative (NPDI) on postnatal inpatient psychiatric hospitalisation. Based on individual hospital admissions data from New South Wales and Western Australia, we found that the NPDI reduced inpatient psychiatric hospital admission by up to 50% [0.9% point reduction (95% CI 0.70-1.22)] in the first postnatal year. The greatest reduction was observed for adjustment disorders. The NPDI appears to be associated with fewer post-birth psychiatric disorders hospital admissions; this suggests earlier detection of psychiatric disorders resulting in early care of women at risk during their perinatal period.

Pregnancy-associated cancers and birth outcomes in children: a Danish and Swedish population-based register study

ObjectivesThis study aims to estimate the association between pregnancy-associated maternal cancers, diagnosed both prenatally and postnatally, and birth outcomes.DesignPopulation-based register study.SettingNational registers of Denmark and Sweden.ParticipantsA total of 5 523...

Health-Related Quality of Life and Depression in Women following Intrauterine Interventions in Complicated Monochorionic Twin Pregnancies

Introduction: The aim of this study was to explore maternal health-related quality of life (HRQoL) and depression following intrauterine interventions in complicated monochorionic twin pregnancies at the Medical University Graz. Material and Methods: In a cross-sectional questionnaire survey, women with at least one liveborn infant following intrauterine intervention during 2011 and 2015 were matched with uncomplicated monochorionic and dichorionic pregnancies. All completed the 12-Item Short Form Health Survey to measure HRQoL and the Patient Health Questionnaire-9 to measure depression. Results were compared with local normative values. Results: There were no differences in physical and mental HRQoL as compared to those with uncomplicated pregnancy. However, the whole study population had significantly lower HRQoL scores (p < 0.001) than the normative sample. Additionally, 11% of the whole study population experienced moderate (6.2%) or moderately severe (4.6%) depression. Women following uncomplicated dichorionic pregnancy revealed more depressive symptoms compared to women with intervention. Discussion: Women with at least one surviving infant following intervention in complicated monochorionic twin pregnancy do not seem to have an impaired HRQoL as compared to women following uncomplicated monochorionic or dichorionic pregnancies. However, twin pregnancy itself appears to impair HRQoL, at least in the first 4 postnatal years.

Relationship between sonographic markers and fetal chromosome abnormality during 16-18 weeks of pregnancy

Objective: To analysis of fetal ultrasound soft index positive cases during 16-18 weeks of pregnancy, and to explore the relationship with chromosomal abnormalities in order to increase the positive rate of invasive prenatal diagnosis and reduce the rate of missed diagnosis. Methods: A total of 569 cases which were diagnosed with positive soft markers in the department of gynecology and obstetrics of the Second Hospital of Jilin University from Jan.2016 to Jan.2017 were studied by ultrasonography. Twenty-five cases were lost in follow-up and finally 544 cases were included as group A. Those fetuses who combined with other malformations were induced labor. Non-invasive DNA examination was recommended for continued pregnant women, and those pregnant women whose results were high risk underwent the amniotic cavity puncture. When the fetal aneuploidy was confirmed, they chose induced labor. We followed the rest of those patients until postnatal half year. Randomly selected 544 cases during 16-18 weeks of pregnancy without obvious abnormalities into group B, followed up to half a year after birth. Results: In group A, 7 of the 544 cases were combined with other severe malformation in the beginning, among the remaining 537 patients, 273 of them received non-invasive DNA examination. Ten cases were high risk results, all of them underwent the amniotic cavity puncture with the result of chromosome abnormality, and they chose induced labor. Six cases were found other malformation in the second trimester who chose induced labor, and the rest 521 cases followed until the fetuses was born after half year had a favorable prognosis. In group B, 1 cases of severe deformities and 1 cases of haploid fetuses were found in 544 fetuses. The incidence of haploid fetus in group A and group B were 1.8% and 0.2%, respectively, with statistically significant (P<0.05). The incidence of severe malformation in group A and group B were 2.3% and 0.2%, respectively, with statistically significant (P<0.05). Conclusions: During 16-18 weeks of pregnancy, sonographic markers may indicate an increased risk in fetal chromosomal abnormalities. The risk of serious malformation was increased in the fetuses with ultrasonic soft marker positive, but there was no specificity.

The Silent Epidemic – Maternal Mental Health: Postpartum Depression

The paper emphasizes a thorough knowledge and assessment of maternal mental health including prenatal and postpartum depression and their risk factors. These include barriers to screening, treatment for women, alongside the unspoken stigma associated to postpartum depression. Likewise, the role of the mother’s mental health and the lack of attunement to the infant can have effects on both the mother and child as a pair. According to Hoffman, Cooper and Powell, (2017) a well known neuropsychologist, Allan Schore shares that the first three years of a child’s life are significant, which covers the internal road map and life span of a child’s psychopathology. Each experience, whether traumatic or positive interaction, is interlinked to a child’s brain chemistry. Also, a healthy attachment based on interactions from parents and caregivers can transmit to a child’s development. This paper employs meta-analysis and statistical analysis of literature reviews and seminal knowledge to construct the importance of addressing maternal mental health and postpartum depression and the significance of the early stages of attachment. The role of mothers’ attachment with infants from prenatal to postnatal years and how they assemble a healthy social and emotional development promotes cognitive development as well as positive family functioning were discussed. Keywords: Postpartum Depression, Maternal Mental Health, Screening, Attachment, Family Function

First-year development of modules and hubs in infant brain functional networks

The human brain develops rapidly in the first postnatal year, in which rewired functional brain networks could shape later behavioral and cognitive performance. Resting-state functional magnetic resonances imaging (rs-fMRI) and complex network analysis have been widely used for characterizing the developmental brain functional connectome. Yet, such studies focusing on the first year of postnatal life are still very limited. Leveraging normally developing longitudinal infant rs-fMRI scans from neonate to one year of age, we investigated how brain functional networks develop at a fine temporal scale (every 3 months). Considering challenges in the infant fMRI-based network analysis, we developed a novel algorithm to construct the robust, temporally consistent and modular structure augmented group-level network based on which functional modules were detected at each age. Our study reveals that the brain functional network is gradually subdivided into an increasing number of functional modules accompanied by the strengthened intra- and inter-modular connectivities. Based on the developing modules, we found connector hubs (the high-centrality regions connecting different modules) emerging and increasing, while provincial hubs (the high-centrality regions connecting regions in the same module) diminishing. Further region-wise longitudinal analysis validates that different hubs have distinct developmental trajectories of the intra- and inter-modular connections suggesting different types of role transitions in network, such as non-hubs to hubs or provincial hubs to connector hubs et al. All findings indicate that functional segregation and integration are both increased in the first year of postnatal life. The module reorganization and hub transition lead to more efficient brain networks, featuring increasingly segregated modular structure and more connector hubs. This study provides the first comprehensive report of the development of functional brain networks at a 3-month interval throughout the first postnatal year of life, which provides essential information to the future neurodevelopmental and developmental disorder studies.

Comparing Adult Hippocampal Neurogenesis Across Species: Translating Time to Predict the Tempo in Humans.

Comparison of neurodevelopmental sequences between species whose initial period of brain organization may vary from 100 days to 1,000 days, and whose progress is intrinsically non-linear presents large challenges in normalization. Comparing adult timelines when lifespans stretch from 1 year to 75 years, when underlying cellular mechanisms under scrutiny do not scale similarly, presents challenges to simple detection and comparison. The question of adult hippocampal neurogenesis has generated numerous controversies regarding its simple presence or absence in humans versus rodents, whether it is best described as the tail of a distribution centered on early neural development, or is several distinct processes. In addition, adult neurogenesis may have substantially changed in evolutionary time in different taxonomic groups. Here, we extend and adapt a model of the cross-species transformation of early neurodevelopmental events which presently reaches up to the equivalent of the third human postnatal year for 18 mammalian species (www.translatingtime.net) to address questions relevant to hippocampal neurogenesis, which permit extending the database to adolescence or perhaps to the whole lifespan. We acquired quantitative data delimiting the envelope of hippocampal neurogenesis from cell cycle markers (i.e., Ki67 and DCX) and RNA sequencing data for two primates (macaque and humans) and two rodents (rat and mouse). To improve species coverage in primates, we gathered the same data from marmosets (Callithrix jacchus), but additionally gathered data on a number of developmental milestones to find equivalent developmental time points between marmosets and other species. When all species are so modeled, and represented in a common time frame, the envelopes of hippocampal neurogenesis are essentially superimposable. Early developmental events involving the olfactory and limbic system start and conclude possibly slightly early in primates than rodents, and we find a comparable early conclusion of primate hippocampal neurogenesis (as assessed by the relative number of Ki67 cells) suggesting a plateau to low levels at approximately 2 years of age in humans. Marmosets show equivalent patterns within neurodevelopment, but unlike macaque and humans may have wholesale delay in the initiation of neurodevelopment processes previously observed in some precocial mammals such as the guinea pig and multiple large ungulates.

Biphasic dendritic growth of dorsolateral prefrontal cortex associative neurons and early cognitive development

AimTo analyze postnatal development and life-span changes of apical dendrite side branches (oblique dendrites) from associative layer IIIC magnopyramidal neurons in the human dorsolateral prefrontal cortex and to compare the findings with the previously established pattern of basal dendrite development.MethodsWe analyzed dendritic morphology from 352 rapid-Golgi impregnated neurons (10-18 neurons per subject) in Brodmann area 9 from the post-mortem tissue of 25 subjects ranging in age from 1 week to 91 years. Data were collected in the period between 1994 and 1996, and the analysis was performed between September 2017 and February 2018. Quantitative dendritic parameters were statistically analyzed using one-way analysis of variance and two-tailed t tests.ResultsOblique dendrites grew rapidly during the first postnatal months, and the increase in the dendrite length was accompanied by the outgrowth of new dendritic segments. After a more than one-year-long “dormant” period of only fine dendritic rearrangements (2.5-16 months), oblique dendrites displayed a second period of marked growth, continuing through the third postnatal year. Basal and oblique dendrites displayed roughly the same growth pattern, but had considerably different topological organization in adulthood.ConclusionOur analysis confirmed that a biphasic pattern of postnatal dendritic development, together with a second growth spurt at the age of 2-3 years, represents a unique feature of the associative layer IIIC magnopyramidal neurons in the human dorsolateral prefrontal cortex. We propose that these structural changes relate to rapid cognitive development during early childhood.

A One-center Study of Sixteen Patients with Pregnancy-associated Breast Cancer: Clinicopathological Characteristics and Survival

Aim: Cancer treatment is of special importance during pregnancy, concerning the health of both mother and baby. Treatment of pregnancy-associated breast cancer (PABC) has become even more important today because women tend to delay pregnancy to later ages and because of women who desire to conceive while under treatment for breast cancer. This retrospective study is aimed at investigating the clinical, radiological and histopathological characteristics and PABC treatment outcomes of patients who had long-term follow-up.Materials and Methods: Sixteen women diagnosed with PABC were included in this study. We evaluated the clinicopathological characteristics, gestational history, and survival outcomes of the patients who had been treated and followed up for breast cancer during pregnancy and the first postnatal year at Istanbul University Institute of Oncology in 2010–2017.Results: The median patient age was 32 (21–41) years. The median gestational week of diagnosis in pregnant patients was 26 (11–35) weeks while the mean time elapsed after delivery until diagnosis in postpartum patients was 9.3 (±3.6) months. The median follow-up time was 47.5 (5–99) months. The mean disease-free survival (DFS) and overall survival (OS) were calculated because the median DFS and OS could not be computed. The mean OS and DFS values were 87.8±7.3 and 77.6±8.5 months,respectively.Discussion and Conclusion: Breast cancer in pregnancy is a special health condition that should be treated and followed up by a multidisciplinary team. Primary surgical intervention should not be delayed. While chemotherapy could be administered safely in the first and second trimesters, radiotherapy and targeted and endocrine treatments should be postponed until after delivery. Reporting and long-term follow-up of cases of pregnancy and cancer concurrence is essential for increasing the relevant knowledge.

Early Life Exposure to Fine Particulate Matter and Working Memory and Attention

Growing evidence has related exposure to air pollution to decelerated cognitive development in children. However, the relevant widow of exposure for such an association is yet to be established. The objective of this work was to evaluate the associations between exposures to particulate matter &amp;#8804; 2.5 µm (PM2.5) at different prenatal and postnatal periods and cognitive function in children to identify important windows of exposure.This study was based on 2,221 children (8.5 &amp;#177; 0.9 years old) recruited from 39 schools across Barcelona, Spain (2012). We applied land use regression models to estimate residential PM2.5 exposure during the prenatal period and the first seven years of life for each participant. Computerized n-back tests to assess working memory (WM) and attentional network tasks (ANT) to assess attentiveness (consistency in response time) and executive function were repeated four times within a year. We used linear mixed effects models with participant and schools as random effects to explore the associations between cognitive development and annual PM2.5 averages of pre-natal and post-natal exposure, adjusted for relevant covariates.Detrimental periods for WM were identified for the fifth and sixth year of life. An interquartile range (IQR) increase of PM2.5 at year 6 resulted in a reduction of -4.62 (95%CI: -8.19, -1.04) points in WM. Important differences were observed by sex, with boys having significant negative effects on WM for all the periods except year 2, while no vulnerable period was observed for girls. Periods of significant detrimental effects on the executive function were identified at the prenatal stage and from postnatal year 4 until 7. No significant differences were observed between boys and girls in the attention domains (attentiveness and executive function).Early life exposure to PM2.5 was detrimentally associated with fundamental cognitive abilities including working memory and executive function.

Bone trait ranking in the population is not established during antenatal growth but is robustly established in the first postnatal year.

Efforts to understand the pathophysiology of bone fragility must focus on bone traits during growth. We hypothesized that variance in individual trait ranking in the population distribution is established by genetic factors and is reflected in foetal trait ranking in early pregnancy, but intrauterine factors modify trait ranking in late pregnancy, followed by the reinstating of this ranking during the first postnatal year. Thus, relations with paternal factors are present in early pregnancy but are then lost and subsequently reinstated postnatal. We recruited 399 healthy pregnant women aged 20–42 years from The Mercy Hospital for Woman in Melbourne, Australia. Foetal femur length (FL) and knee-heel length (KHL) were measured by ultrasound during gestation, and FL, KHL, body length and weight were measured in neonates, infants, and parents. The z-scores were calculated using Royston models. Pearson correlation was used to assess tracking and linear mixed models to test the associations. Correlations between FL and KHL z-scores of the same trait at 20 and 30 weeks gestation, at birth, and at 12 and 24 months of age (r = 0.1–0.3) and of body length and weight at birth, and 6, 12 and 24 months (r = 0.3–0.5) became more robust after 6–12 months (r = 0.4–0.8). FL and KHL z-scores at 20 weeks gestation accounted for 4–5% of total variance, while FL, KHL, body length and weight z-scores at birth accounted for 13–26% of total variance in the same traits at 24 months. Maternal FL and KHL were associated with foetal FL and KHL at 20 and 30 weeks, but there were no such associations for paternal FL and KHL with foetal traits during gestation. Both maternal and paternal traits were associated with infant traits. Tracking in traits is not established antenatal but is robustly established at 6–12 months of age.