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. A cross-sectional study was conducted using recently collected data for 918 children aged 0-38 months from socially marginalized communities in 23 Mexican municipalities. The ECD outcomes of the children were estimated based on indicators of chronic undernutrition and neurodevelopment (normal, lagging and at risk of delay). The distribution of outcomes was described across the ECD proximal determinants analyzed, including the co-occurrence of chronic undernutrition and suboptimal neurodevelopment. Covariate-adjusted prevalence of the ECD outcomes and co-occurrences were calculated as post-estimations from a multiple multinomial logistic regression. The prevalence of chronic undernutrition was 23.5%; 45.9% of children were classified with neurodevelopmental lag, and 11% at risk of neurodevelopmental delay. The prevalence of stunting co-occurring with suboptimal neurodevelopment came to 15.4%. The results of the multinomial logistic regression model indicated that early gestational age, low birth weight, a low household socioeconomic level, being male and having numerous siblings were all associated with the co-occurrence of chronic undernutrition and suboptimal child neurodevelopment. This study identified important predictors of child development in the first three years of life, specifically in two of its principal indicators: nutritional and neurodevelopmental status. Most of the predictors observed can be improved by means of social programs and interventions. Trial registration: ClinicalTrials.gov ID: NCT04210362.
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. We performed a cross-sectional study based on data collected in 2019-2020 during home visits to 1,176 children aged 0-38 months across 24 highly marginalized locations in Oaxaca. We assessed nutritional status according to the World Health Organization 2006 child-growth standards and ECD status using the Child Development Evaluation Test, 2.sup.nd Edition. We stratified results by sex. Prevalence of stunting was 5.3 percentage points (p.p.) higher (p = 0.023) in males (25.3%; 95% CI: 20.2%, 31.1%) compared to females (20.0%; 95% CI: 15.0%, 26.1%). Overall prevalence rates stood at 5.7% (95% CI: 4.0%, 8.1%) for underweight, 1.5% (95% CI: 0.9%, 2.7%) for wasting and 3.6% (95% CI: 2.3%, 5.7%) for overweight/obesity, with no significant differences by sex. Prevalence of normal development was 8.3 p.p. lower (p = 0.001) in males (39.3%; 95% CI: 34.5%, 44.4%) compared to females (47.6%; 95% CI: 41.6%, 53.6%). By development area, the highest prevalence of suboptimal outcomes among children with developmental lag or at risk of delay was observed in their gross motor and language skills: 24.1% (95% CI: 20.0%, 28.8%) and 38.6% (95% CI: 34.0%, 43.3%), respectively. The largest difference between the sexes was found in the language area. Our results show that childhood development strategies have been insufficient thus far in the studied population. Programs specifically designed to prevent ECD lags and bridge inequality gaps are urgently needed.
Humans are exposed to mixtures of chemicals across their lifetimes, a concept sometimes called the "exposome." Mixtures likely have temporal "critical windows" of susceptibility like single agents ...and measuring them repeatedly might help to define such windows. Common approaches to evaluate the effects of chemical mixtures have focused on their effects at a single time point. Our goal is to expand upon these previous techniques and examine the time-varying critical windows for metal mixtures on subsequent neurobehavior in children.
We propose two methods, joint weighted quantile sum regression (JWQS) and meta-weighted quantile sum regression (MWQS), to estimate the effects of chemical mixtures measured across multiple time points, while providing data on their critical windows of exposure. We compare the performance of both methods using simulations. We also applied both techniques to assess second and third trimester metal mixture effects in predicting performance in the Rapid Visual Processing (RVP) task from the Cambridge Neuropsychological Test Automated Battery (CANTAB) assessed at 6-9 years in children who are part of the PROGRESS (Programming Research in Obesity, GRowth, Environment and Social Stressors) longitudinal cohort study. The metals, arsenic, cadmium (Cd), cesium, chromium, lead (Pb) and antimony (Sb) were selected based on their toxicological profile.
In simulations, JWQS and MWQS had over 80% accuracy in classifying exposures as either strongly or weakly contributing to an association. In real data, both JWQS and MWQS consistently found that Pb and Cd exposure jointly predicted longer latency in the RVP and that second trimester exposure better predicted the results than the third trimester. Additionally, both JWQS and MWQS highlighted the strong association Cd and Sb had with lower accuracy in the RVP and that third trimester exposure was a better predictor than second trimester exposure.
Our results indicate that metal mixtures effects vary across time, have distinct critical windows and that both JWQS and MWQS can determine longitudinal mixture effects including the cumulative contribution of each exposure and critical windows of effect.
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.
We analyzed primary data obtained through a questionnaire administered to mothers who were the primary caregivers of 1045 girls and boys 0–38 months of age. The instrument was specifically designed for our study in order to explore the knowledge of participants about physical, neurological and psycho-affective development during childhood. We performed fractional regression analysis to assess the predictors of ECD knowledge.
The mean score of maternal ECD knowledge increased with their age and schooling as well as with their levels of cognitive ability and self-esteem. Irrespective of age at first birth, mean knowledge was relatively high for women with high school education and low for women with elementary or no formal education, a gradient with respect to age at fist birth was more marked among women with middle school education. ECD knowledge scores increased among mothers from households enjoying higher socioeconomic levels and from households with health insurance. Scores were lower for indigenous households regardless of their participation in social programs.
Public policies on ECD should promote programs that are not only adapted to specific contexts, but also designed to improve shared child-rearing, early childhood care and as well as psycho-emotional education skills as a pathway to healthier ECD. The participation of families and communities in sensitive childhood care should form part of multisectoral programs involving education, health and wellbeing.
•ECD knowledge among the evaluated mothers was suboptimal;•It is essential to implement participative strategies to ensure that caregivers enjoy optimal emotional conditions for absorbing the key ECD concepts;•Additional research into the factors that shape ECD knowledge in deprived contexts will contribute to inform effective ECD interventions;•It is essential to explore which factors are conducive to the development of resilient individuals and communities in deprived contexts.
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. Therefore, children in Oaxaca are at a high risk of suboptimal ECD. In 2014, the non-governmental organization (NGO) Un Kilo de Ayuda started to implement the Neurological and Psycho-affective Early Childhood Development Program in eighty marginalized communities of Oaxaca. In this article, we present the impact evaluation design to estimate the effect of this program on ECD.
We will use a cluster randomized stepped-wedge design with an allocation ratio of 1:1. Communities will be randomly assigned to each study group: four groups of twenty communities each. We expect that children from intervened communities will show better ECD outcomes.
This study is one of the few rigorous assessments of the effect of an ECD program on the neurodevelopment of Mexican children recruited in their first 3 years of life from communities of high social vulnerability. Our study design is recommended when the way in which outcomes are measured and assessed depends on age, self-selection is present, and assignment is performed at an aggregate level. Implementation research will be conducted prior to study launch and quality control measures will be in place to maximize the fidelity of study design implementation.
ClinicalTrials.gov NCT04210362.
•Lead is a neurotoxicant associated with neurodevelopmental deficits.•Prepulse inhibition (PPI) deficits are associated with neurological disorders.•We estimated the causal effect of prenatal lead ...exposure on PPI in children.•Our findings suggest prenatal lead exposure causes PPI deficits in children.•PPI may be an objective biomarker of neurotoxicant effects on the brain.
During pregnancy, maternal lead from earlier exposures mobilizes and crosses placental barriers, placing the developing fetus at risk for lead exposure and neurodevelopmental deficits. Some neuronal circuits known to be affected in neurodevelopment disorders can be probed with simple physiological behavioral paradigms. One such neural biomarker is Pre-Pulse Inhibition (PPI), an indicator of adequate sensorimotor gating processing. In clinical studies, deficits in PPI have been associated with neurodevelopmental disorders in human subjects. To our knowledge, no studies have examined the use of PPI as a biomarker of toxicant effects on the brain in epidemiological studies. We aimed to estimate the causal effect of prenatal lead exposure, assessed by maternal cortical bone lead concentrations, on PPI in 279 children from Mexico City. in vivo maternal cortical bone lead measurements were taken at four weeks postpartum at the mid-tibia shaft using a K-Shell X-ray fluorescence instrument. PPI recording occurred in an isolated clinical setting and eye blink responses were measured using electromyography. We assessed if the conditions for causal inference held in our study and used the results of our assessment to estimate the causal effect of prenatal lead exposure on PPI using an ordinary least squares regression model, a marginal structural model, and the parametric g-formula. Results were consistent across the three modeling approaches. For the parametric g-formula, a one standard deviation (10.0 μg/g) increase in prenatal lead significantly reduced PPI by approximately 19.0 % (95 % CI: 5.4 %, 34.3 %). This decrease is similar in magnitude to clinical studies on schizophrenia, which have observed PPI impairments in patients with schizophrenia as compared to controls. Our results are consistent with findings from other studies establishing an association between lead exposure and neurodevelopmental disorders in children and suggest that PPI may be useful as an objective biomarker of toxicant effects on the brain.
In this study, the bacterial communities associated with the rhizospheres of pioneer plants Bahia xylopoda and Viguiera linearis were explored. These plants grow on silver mine tailings with high ...concentration of heavy metals in Zacatecas, Mexico. Metagenomic DNAs from rhizosphere and bulk soil were extracted to perform a denaturing gradient gel electrophoresis analysis (DGGE) and to construct 16S rRNA gene libraries. A moderate bacterial diversity and twelve major phylogenetic groups including Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes, Chloroflexi, Firmicutes, Verrucomicrobia, Nitrospirae and Actinobacteria phyla, and divisions TM7, OP10 and OD1 were recognized in the rhizospheres. Only 25.5% from the phylotypes were common in the rhizosphere libraries and the most abundant groups were members of the phyla Acidobacteria and Betaproteobacteria (Thiobacillus spp., Nitrosomonadaceae). The most abundant groups in bulk soil library were Acidobacteria and Actinobacteria, and no common phylotypes were shared with the rhizosphere libraries. Many of the clones detected were related with chemolithotrophic and sulfur-oxidizing bacteria, characteristic of an environment with a high concentration of heavy metal-sulfur complexes, and lacking carbon and organic energy sources.
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). Report of wheeze in the past 12 months (current wheeze) and asthma were obtained using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire at 48 and 72 months. Associations were analyzed using a modified Poisson regression adjusted for covariates, and in interaction models.
Results
Both postpartum and recurrent depression were associated with higher risk of current wheeze (relative risk RR: 1.87, 95% confidence interval CI: 1.21, 2.90; RR: 2.41, 95% CI: 1.53, 3.79) and asthma at 48 months (RR: 2.42, 95% CI: 1.01, 5.84; RR: 2.45, 95% CI: 1.02, 5.84). In interaction analyses, associations were stronger in females. Recurrent depression was associated with a higher risk of current wheeze at 48 months in females (RR: 4.34, 95% CI: 2.02, 9.32) when compared to males (RR: 1.89, 95% CI: 1.05, 3.39).
Conclusions
Postpartum and recurrent depression were associated with a higher risk of wheeze and asthma in children. Understanding the temporal‐ and sex‐specific effects of maternal depression may better inform prevention strategies.
•In children, Prepulse inhibition (PPI) deficits are associated with neurodevelopmental disorders.•We used a data-driven prediction model to identify six important predictors of PPI.•We found that ...typical predictors of neurodevelopmental disorders also predict PPI.•Our findings underscore the potential utility of PPI as a biological marker of neurodevelopmental disorders.
Prepulse inhibition (PPI) is a sensorimotor gating mechanism that reduces interfering influences to the neural processing of incoming stimuli, and is associated with several neurodevelopmental disorders. To date, research on PPI and neurodevelopmental disorders has primarily been in cross-sectional, clinical settings. In this prospective, epidemiologic study, we used a data-driven prediction model to identify socio-demographic predictors of PPI in children and adolescents from Mexico City to inform future etiologic studies evaluating PPI. We conducted variable selection and validation using a modified version of the multiple imputation random lasso (MIRL) variable selection algorithm. MIRL identified six predictors of PPI at a stimulus onset asynchrony of 120 ms or 240 ms. Of those six predictors, maternal education, birthweight, and total breastfeeding months were highlighted as previously unstudied variables associated with enhanced PPI. Our findings highlight the potential value of PPI as an adjunct screening tool for identifying children at risk for neurodevelopmental disorders and underscore the relevance for validation research on this topic.
Con base en el estudio de especies realizado en las áreas protegidas dentro del estado de Hidalgo, identificamos un espécimen de martucha cazado en la porción sur del municipio de Zacualtipan. El ...espécimen fue cazado durante la primera semana de mayo de 2016. Confirmamos la presencia reciente de la especie en el estado de Hidalgo y en la Reserva de la Biosfera Barranca de Metztitlán. Por lo tanto, esperamos realizar más estudios en esta área que brinden una mejor comprensión de este taxón en México y su asociación con la pérdida de vegetación.
PDF
