Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia…

Thyroid Function in Early Pregnancy, Child IQ, and Autistic Traits: A Meta-Analysis of Individual Participant Data

Context: Low maternal free T4 (FT4) has been associated with poor child neurodevelopment in some single-center studies. Evidence remains scarce for the potential adverse effects of high FT4 and whether associations differ in countries with different iodine status. Objective: To assess the association of maternal thyroid function in early pregnancy with child neurodevelopment in countries with a different iodine status. Design, Setting, and Participants: Meta-analysis of individual participant data from 9036 mother–child pairs from three prospective population-based birth cohorts: INMA [Infancia y Medio Ambiente (Environment and Childhood project) (Spain)], Generation R (Netherlands), and AL…

Author response: Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

Poor mothers, unhealthy children: the transmission of health inequalities in the INMA study, Spain

Background The health of pregnant women and their fetuses are especially sensitive to socioeconomic conditions. This study analyzes the impact of maternal socioeconomic status (SES), evaluated by occupation and maternal education level, in preterm births (PTBs) and in small for gestational age (SGA) fetuses, considering the effect of the potential mediating factors on the SES and birth outcomes. Methods A total of 2497 mother/newborn dyads from the INMA-Spain project were studied. We examined maternal occupation and education in relation to PTB and SGA along with covariate data, using logistic regression analysis. Adjusted models for each of the outcome variables in relation to SES indicato…

Knot placement in the Distributed non-linear lag models (DNLM) framework

Prenatal mercury exposure in a multicenter cohort study in Spain

Background: Mercury is a ubiquitous heavy metal that may negatively affect human health. It is desirable to investigate mercury exposure in vulnerable populations. Objective: To determine the concentrations of total mercury (T-Hg) in cord blood and to evaluate the role of maternal fish consumption in a Spanish mother and child cohort. Methods: A total of 1883 mother and child pairs from a population-based cohort were included between 2004 and 2008. T-Hg concentrations were measured in whole cord blood and maternal seafood consumption was ascertained by means of a food-frequency questionnaire. Linear regression was used in stratified analyses, while a joint model was adjusted using a mixed-e…

Early Life Exposure to Perfluoroalkyl Substances (PFAS) and ADHD: A Meta-Analysis of Nine European Population-Based Studies

Introduction: To date, the evidence for an association between perfluoroalkyl substances (PFAS) exposure and attention deficit and hyperactivity disorder (ADHD) is inconclusive. Objective: We investigated the association between early life exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), and ADHD in a collaborative study including nine European population-based studies, encompassing 4,826 mother-child pairs. Methods: Concentrations of PFOS and PFOA were measured in maternal serum/plasma during pregnancy, or in breast milk, with different timing of sample collection in each cohort. We used a validated pharmacokinetic model of pregnancy and lactation to estimate…

Identifying sensitive windows of exposure to NO2 and fetal growth trajectories in a Spanish population-based birth cohort

Prenatal manganese exposure and neuropsychological development in early childhood in the INMA cohort.

Abstract Introduction Manganese (Mn) is an essential element, diet being its main source. Some epidemiological studies have found that a prenatal excess of Mn could negatively affect neuropsychological development during infancy, but the evidence is inconclusive. The aim of this study was to explore the relationship between maternal serum Mn concentrations and child neuropsychological development assessed at 1 year of age. Methods study subjects were 1179 mother–child pairs from two Spanish cohorts (Valencia and Gipuzkoa) of the INMA (Environment and Childhood) Project. Mn was measured in serum samples collected during the first trimester of pregnancy. Child neuropsychological development w…

Maternal Iodine Status During Pregnancy Is Not Consistently Associated with Attention-Deficit Hyperactivity Disorder or Autistic Traits in Children

Background: Severe iodine deficiency during pregnancy can cause intellectual disability, presumably through inadequate placental transfer of maternal thyroid hormone to the fetus. The association between mild-to-moderate iodine deficiency and child neurodevelopmental problems is not well understood. Objectives: We investigated the association of maternal iodine status during pregnancy with child attention-deficit hyperactivity disorder (ADHD) and autistic traits. Methods: This was a collaborative study of 3 population-based birth cohorts: Generation R (n = 1634), INfancia y Medio Ambiente (n = 1293), and the Avon Longitudinal Study of Parents and Children (n = 2619). Exclusion criteria were…

Association of Maternal Iodine Status With Child IQ: A Meta-Analysis of Individual Participant Data

Abstract Context Although the consequences of severe iodine deficiency are beyond doubt, the effects of mild to moderate iodine deficiency in pregnancy on child neurodevelopment are less well established. Objective To study the association between maternal iodine status during pregnancy and child IQ and identify vulnerable time windows of exposure to suboptimal iodine availability. Design Meta-analysis of individual participant data from three prospective population-based birth cohorts: Generation R (Netherlands), INMA (Spain), and ALSPAC (United Kingdom); pregnant women were enrolled between 2002 and 2006, 2003 and 2008, and 1990 and 1992, respectively. Setting General community. Participa…

Influence of fetal glutathione S-transferase copy number variants on adverse reproductive outcomes

A nested case-control association study was designed to investigate the influence of maternal and fetal copy number variants (CNVs) on reproductive outcomes. Genotypes of ten CNVs encompassing GST and CYP genes were assessed. Significant associations were only found for child CNV genotypes. In particular, the child GSTM1 insertion allele was associated with prematurity protection (odds ratio, 95% CI: 0.67, 0.51-0.89; P < 0.01), whereas the child GSTT2B insertion allele was associated with an increased risk of being small for gestational age (odds ratio, 95% CI: 1.33, 1.07-1.67; P = 0.01). The study highlights the role of the fetal genome in prenatal development and also the need to analyse …

Prenatal perfluoroalkyl substance exposure and neuropsychological development throughout childhood: The INMA Project.

Abstract Background Perfluoroalkyl substances (PFASs) have been related to neurodevelopmental toxicity in animals. However, human studies are inconclusive. Objectives To evaluate the association between prenatal PFAS exposure and neuropsychological development during childhood. Methods 1240 mother–child pairs from the Spanish INMA Project were analyzed. Perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorononanoic acid (PFNA) were measured in first-trimester maternal plasma. Neuropsychological development was assessed at 14 months, 4–5 and 7 years covering four domains: general cognitive, general motor, attention, and working me…

Are low fluoride levels in drinking water really detrimental for neuropsychological neurodevelopment in childhood?

Methods: Fluoride was measured in drinking water (DW) and in urine (1st and 3rd trimesters of pregnancy). The 369 mother-children pairs of the Spanish INMA cohort participating in the study reporte...

Maternal occupational exposure to chemicals and neurocognitive development at 4-5 years of age

Influence of the Urban Exposome on Birth Weight

Background: The exposome is defined as the totality of environmental exposures from conception onwards. It calls for providing a holistic view of environmental exposures and their effects on human health by evaluating multiple environmental exposures simultaneously during critical periods of life. Objective: We evaluated the association of the urban exposome with birth weight. Methods: We estimated exposure to the urban exposome, including the built environment, air pollution, road traffic noise, meteorology, natural space, and road traffic (corresponding to 24 environmental indicators and 60 exposures) for nearly 32,000 pregnant women from six European birth cohorts. To evaluate associatio…

The Urban Exposome during Pregnancy and Its Socioeconomic Determinants

Background: The urban exposome is the set of environmental factors that are experienced in the outdoor urban environment and that may influence child development. Objective: The authors’ goal was to describe the urban exposome among European pregnant women and understand its socioeconomic determinants. Methods: Using geographic information systems, remote sensing and spatio-temporal modeling we estimated exposure during pregnancy to 28 environmental indicators in almost 30,000 women from six population-based birth cohorts, in nine urban areas from across Europe. Exposures included meteorological factors, air pollutants, traffic noise, traffic indicators, natural space, the built environment…

Maternal seafood consumption during pregnancy and child attention outcomes: a cohort study with gene effect modification by PUFA-related genes

Abstract Background There is a need to test the fetal programming theoretical framework in nutritional epidemiology. We evaluated whether maternal seafood intake during pregnancy was associated with 8-year-old attention outcomes after adjusting for previous child seafood intake and cognitive function. We also explored effect modification by several single nucleotide polymorphisms (SNPs) related with polyunsaturated fatty acid (PUFA) metabolism. Methods Our final analyses included 1644 mother-child pairs from the prospective INMA (INfancia y Medio Ambiente) cohort study (Spain, recruitment between 2003 and 2008). We used food frequency questionnaires to assess prenatal and postnatal seafood …

Association of placental concentrations of phenolic endocrine disrupting chemicals with cognitive functioning in preschool children from the Environment and Childhood (INMA) Project.

Developmental exposure to bisphenol A (BPA) and other phenolic endocrine disrupting chemicals (EDCs) may affect child neurodevelopment, but data on the effects of prenatal exposure to phenols on cognitive function remain sparse. Our aim was to examine the association of placental concentrations of several phenolic EDCs, including BPA, parabens (PBs), and benzophenones (BzPs), with cognitive development in preschool children from the Environment and Childhood (INMA) Project in Spain. Concentrations of BPA, four PBs (methylparaben [MePB], ethylparaben [EtPB], propylparaben [PrPB], and butylparaben [BuPB]), and six BzPs (BzP-1, BzP-2, BzP-3, BzP-6, BzP-8, and 4-hydroxybenzophenone [4-OH-BzP]) …