Associations between psychosocial stress, child's anxiety, and lung function in mid-childhood.

Background: Reducing the risk of respiratory disease during the plastic stages of lung development could have long-term health impacts. Psychosocial stress has been previously linked to adverse childhood respiratory outcomes, but the influence of child's anxiety and sex differences has not been completely elucidated.

Objective: To evaluate the association among maternal stress, child anxiety, and lung function in children and to explore differences by sex.

Sensitive development windows of prenatal air pollution and cognitive functioning in preschool age Mexican children.

Introduction: Neurotoxicity resulting from air pollution is of increasing concern. Considering exposure timing effects on neurodevelopmental impairments may be as important as the exposure dose. We used distributed lag regression to determine the sensitive windows of prenatal exposure to fine particulate matter (PM) on children's cognition in a birth cohort in Mexico.

Proximal determinants of suboptimal early child development during the first three years of life in socially deprived Mexican contexts.

Assessing the status and determinants of early child development (ECD) requires accurate and regularly updated measurements. Yet, little information has been published on the subject in low- and middle-income countries, particularly regarding the proximal determinants of childhood development in contexts of high social marginalization. This article analyzes the factors that favor or mitigate suboptimal ECD outcomes in Mexico.

Changes in depressive and anxiety symptoms during COVID-19 in children from the PROGRESS cohort.

Background: We assessed associations between maternal stress, social support, and child resiliency during the COVID-19 pandemic in relation to changes in anxiety and depression symptoms in children in Mexico City.

Methods: Participants included 464 mother-child pairs from a longitudinal birth cohort in Mexico City. At ages 8-11 (pre-COVID, 2018-2019) and 9-12 (during COVID, May-Nov 2020) years, depressive symptoms were assessed using the child and parent-reported Children's Depressive Inventory.

Prenatal Co-Exposure to Manganese, Mercury, and Lead, and Neurodevelopment in Children during the First Year of Life.

Lead (Pb), mercury (Hg), and manganese (Mn) are neurotoxic, but little is known about the neurodevelopmental effects associated with simultaneous prenatal exposure to these metals. We aimed to study the associations of Pb, Hg, and Mn prenatal levels (jointly and separately) with neurodevelopment in the first year of life. Methods: Pb, Hg, and Mn blood lead levels were measured in 253 pregnant women.

Early life exposure to lead and its association with parent-reported aggression and conduct problems during childhood and adolescence.

Background And Aim: An association between lead (Pb) exposure and antisocial behaviors has been documented, but findings have been inconclusive. We aimed to estimate the association between prenatal, early childhood, and preadolescent/adolescent (periadolescent) Pb exposure and aggression and conduct problems in periadolescent residents of Mexico City.

Methods: Using information from the ELEMENT cohort study, we assessed prenatal Pb exposure through maternal patella Pb (MPPb) measurement during the puerperium, early childhood (birth to 5 years of age) exposure through a cumulative blood lead index (CBLI), and periadolescent exposure through a blood Pb (BPb) measurement concurrent with the evaluation of the outcomes.

Predictors of maternal knowledge on early childhood development in highly marginalized communities in Mexico: Implications for public policy.

Introduction: Efforts to identify the predictors of maternal knowledge on Early Child Development (ECD) have proven inconclusive thus far, particularly with respect to socially deprived contexts in Low- and Middle-Income Countries (LMICs). We quantified the extent of ECD knowledge among mothers who were the primary caregivers of 0-38-month-old infants in marginalized communities in Mexico. We also explored the characteristics of the children, both individually and with regard to their households, given the influence of these factors on childhood development.

Longitudinal assessment of maternal depression and early childhood asthma and wheeze: Effect modification by child sex.

Background: Studies report associations between maternal mental health and adverse respiratory outcomes in children; however, the impact of timing and duration of maternal distress remains understudied. We sought to longitudinally examine associations between maternal depression and childhood asthma and wheeze, and explore sex differences.

Methods: Maternal depression (n = 601) was assessed using the Edinburgh Depression Scale questionnaire, dichotomized at a clinically relevant cutoff (>12) (a) during pregnancy, (b) postpartum, and (c) postpartum and subsequent time points postnatally (recurrent depression).

Early neurological development and nutritional status in Mexican socially deprived contexts.

Early childhood development (ECD) is a critical stage in the intergenerational process of human development. Targeted interventions depend on accurate and up-to-date ECD measurements. This paper presents estimates for the nutritional and neurodevelopmental status of socially marginalized children in Mexico.

The influence of maternal anxiety and cortisol during pregnancy on childhood anxiety symptoms.

Background: The etiology of child and adolescent anxiety remains poorly understood. Although several previous studies have examined associations between prenatal maternal psychological functioning and infant and child health outcomes, less is known about the impact of maternal anxiety specific to pregnancy and cortisol during pregnancy on childhood anxiety outcomes.

Methods: Participants included 496 mother-child pairs from the PROGRESS longitudinal birth cohort in Mexico City.

Domain-specific effects of prenatal fluoride exposure on child IQ at 4, 5, and 6-12 years in the ELEMENT cohort.

Objective: Prenatal exposure to fluoride has been associated with adverse neurodevelopmental outcomes. However, the neuropsychological profile of fluoride's developmental neurotoxicity at low levels and the stability of this relationship across childhood has not been characterized. We investigated the longitudinal and domain specific effect of prenatal fluoride exposure on IQ among children ages 4, 5, and 6-12 years in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort.

Assessing the effect of an educational intervention on early childhood development among Mexican preschool children in the state of Oaxaca: a study protocol of a cluster randomized stepped-wedge trial.

Background: Early childhood development (ECD) is essential in human capacity building and a critical element in the intergenerational process of human development. In some countries, social programs targeted at improving ECD have proven to be successful. Oaxaca is one of the States with the greatest social inequities in Mexico.

Association between prenatal metal exposure and adverse respiratory symptoms in childhood.

Introduction: Manganese and lead have been cross-sectionally associated with adverse respiratory outcomes in childhood but there is limited data on their combined effects starting in utero. We examined associations between in utero exposure to metals and childhood respiratory symptoms.

Methods: We assessed 633 mother-child dyads enrolled in the Programming Research in Obesity, Growth, Environment, and Social Stressors (PROGRESS) birth cohort in Mexico City.

Mitochondrial DNA Copy Number Adaptation as a Biological Response Derived from an Earthquake at Intrauterine Stage.

An altered mitochondrial DNA copy number (mtDNAcn) at birth can be a marker of increased disease susceptibility later in life. Gestational exposure to acute stress, such as that derived from the earthquake experienced on 19 September 2017 in Mexico City, could be associated with changes in mtDNAcn at birth. Our study used data from the OBESO (Biochemical and Epigenetic Origins of Overweight and Obesity) perinatal cohort in Mexico City.

Prenatal metal mixture concentrations and reward motivation in children.

Reward motivation is a complex umbrella term encompassing the cognitions, emotions, and behaviors involved in the activation, execution, and persistence of goal-directed behavior. Altered reward motivation in children is characteristic of many neurodevelopmental and psychiatric disorders. Previously difficult to operationalize, the Progressive Ratio (PR) task has been widely used to assess reward motivation in animal and human studies, including children.

Maternal FADS2 single nucleotide polymorphism modified the impact of prenatal docosahexaenoic acid (DHA) supplementation on child neurodevelopment at 5 years: Follow-up of a randomized clinical trial.

Background: Variability in the FADS2 gene, which codifies the Delta-6 Desaturases and modulates the conversion of essential n-3 and n-6 fatty acids into long-chain polyunsaturated fatty acids, might modify the impact of prenatal supplementation with n-3 docosahexaenoic acid (DHA) on neurodevelopment.

Objective: To assess if maternal FADS2 single nucleotide polymorphisms (SNPs) modified the effect of prenatal DHA on offspring development at 5 years.

Design: We conducted a post-hoc interaction analysis of the POSGRAD randomized controlled trial (NCT00646360) of prenatal supplementation with algal-DHA where 1094 pregnant women originally randomized to 400 mg/day of preformed algal DHA or a placebo from gestation week 18-22 through delivery.

Dietary fluoride intake during pregnancy and neurodevelopment in toddlers: A prospective study in the progress cohort.

Foods and beverages provide a source of fluoride exposure in Mexico. While high fluoride concentrations are neurotoxic, recent research suggests that exposures within the optimal range may also pose a risk to the developing brain. This prospective study examined whether dietary fluoride intake during pregnancy is associated with toddlers' neurodevelopment in 103 mother-child pairs from the PROGRESS cohort in Mexico City.

Changes in Depressive Symptoms, Stress and Social Support in Mexican Women during the COVID-19 Pandemic.

The aim of this study was to examine changes in depression, stress and social support levels before and during the COVID-19 pandemic in women living in Mexico City. We studied 466 women enrolled in the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) study who completed the Edinburgh Depression Scale (EDS) questionnaire prior (2018-2019) and during the lockdown period of the pandemic (May-November 2020). Psychosocial stress and social support for both time periods were ascertained using the Crisis in Family Systems (CRISYS) questionnaire and the Social Support Network (SSN) Scale, respectively.

Prenatal PM2.5 exposure in the second and third trimesters predicts neurocognitive performance at age 9-10 years: A cohort study of Mexico City children.

Introduction: Prenatal exposure to fine particulate matter air pollution (PM2.5) is an important, under-studied risk factor for neurodevelopmental dysfunction. We describe the relationships between prenatal PM2.

DNA methylation at birth potentially mediates the association between prenatal lead (Pb) exposure and infant neurodevelopmental outcomes.

Early-life lead (Pb) exposure has been linked to adverse neurodevelopmental outcomes. Recent evidence has indicated a critical role of DNA methylation (DNAm) in cognition, and Pb exposure has also been shown to alter DNAm. However, it is unknown whether DNAm is part of the mechanism of Pb neurotoxicity.

Prenatal urinary concentrations of phthalate metabolites and behavioral problems in Mexican children: The Programming Research in Obesity, Growth Environment and Social Stress (PROGRESS) study.

Background: Phthalate exposure has been associated with increased childhood behavioral problems. Existing studies failed to include phthalate replacements and did not account for high correlations among phthalates. Phthalates' exposure is higher in Mexico than in U.

Gestational and peripubertal phthalate exposure in relation to attention performance in childhood and adolescence.

The prevalence of Attention Deficit/Hyperactivity Disorder (ADHD) has been increasing. Research suggests that exposure to endocrine disrupting chemicals such as phthalates may play a role, but studies of in utero phthalate exposure and ADHD-related symptoms beyond early childhood are limited. We investigated associations between measures of in utero phthalate exposure and ADHD symptoms, such as inattention and impulsivity, in childhood (age 6-11 years, n = 221) and in adolescence (age 9-18 years, n = 200), as well as cross-sectional relationships between phthalate exposure and ADHD symptoms in adolescence (n = 491) among participants in the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) cohort.

Prenatal lead exposure and cord blood DNA methylation in PROGRESS: an epigenome-wide association study.

The effects of prenatal lead exposure on child development include impaired growth and cognitive function. DNA methylation might be involved in the underlying mechanisms and previous epigenome-wide association studies reported associations between lead exposure during pregnancy and cord blood methylation levels. However, it is unclear during which developmental stage lead exposure is most harmful.

Early Gestational Exposure to High-Molecular-Weight Phthalates and Its Association with 48-Month-Old Children's Motor and Cognitive Scores.

In utero phthalate exposure has been associated with neurodevelopmental disorders, nevertheless, trimester-specific susceptibility remains understudied. Our aim was to identify susceptible windows to the effects of gestational High-Molecular-Weight Phthalates (HMWP) exposure on 48 months' neurodevelopment. We measured six HMWP metabolites (MEHP, MEHHP, MEOHP, MECPP, MBzP and MCPP) in urine samples collected during each trimester from women in the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) cohort ( = 218).

Prenatal PM exposure and behavioral development in children from Mexico City.

Background: Childhood exposure to air pollution has been linked with maladaptive cognitive development; however, less is known about the association between prenatal fine particulate matter (PM) exposure and childhood behavior.

Objectives: Our aim was to assess the association between prenatal PM exposure and behavioral development in 4-6 year old children residing in Mexico City.

Methods: We used data from 539 mother-child pairs enrolled in a prospective birth cohort in Mexico City.