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. 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.

Discrepancies in infant feeding recommendations between grandmothers and healthcare providers in rural Mexico.

BACKGROUND: Infant feeding practices are rapidly changing within rural areas in Mexico, including indigenous communities. The aim of this study was to compare infant feeding recommendations between grandmothers and healthcare providers, to better understand the factors that may influence these practices within these communities. This study builds on research that recognizes the legacy of colonization as an ongoing process that impacts the lives of people through many pathways, including the substandard healthcare systems available to them. METHODS: Qualitative study based on secondary data analysis from interviews and focus groups guided by a socioecological framework conducted in 2018 in two rural, Indigenous communities in Central Mexico. Participants were purposively selected mothers (n = 25), grandmothers (n = 11), and healthcare providers (n = 24) who offered care to children up to two years of age and/or their mothers. Data were coded and thematically analyzed to contrast the different perspectives of infant feeding recommendations and practices between mother, grandmothers, and healthcare providers. RESULTS: Grandmothers and healthcare providers differed in their beliefs regarding appropriate timing to introduce non-milk foods and duration of breastfeeding. Compared to grandmothers, healthcare providers tended to believe that their recommendations were superior to those from people in the communities and expressed stereotypes reflected in negative attitudes towards mothers who did not follow their recommendations. Grandmothers often passed down advice from previous generations and their own experiences with infant feeding but were also open to learning from healthcare providers through government programs and sharing their knowledge with their daughters and other women. Given the contradictory recommendations from grandmothers and healthcare providers, mothers often were unsure which advice to follow. CONCLUSIONS: There are important differences between grandmothers and healthcare providers regarding infant feeding recommendations. Healthcare providers may perceive their recommendations as superior given the neocolonial structures of the medical system. Public health policies are needed to address the different recommendations mothers receive from different sources, by harmonizing them and following an evidence-informed approach. Breastfeeding programs need to value and to seek the participation of grandmothers.

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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

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. 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, 2nd 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. Trial registration: ClinicalTrials.gov ID: NCT04210362.

A behavioral economics analysis of the participation in early childhood development social programs promoted by civil societies in Mexico.

Based on a behavioral economics (BE) approach, we analyzed the decision to participate in an early childhood development (ECD) program implemented in Mexico by a non-governmental organization. We conducted a literature review and a qualitative study of four localities participating in the ECD program. Situated in the state of Oaxaca, these communities are characterized by high and very high levels of social marginalization. From May 20 to 30, 2019, we collected primary data through semi-structured interviews (n = 30) and focus groups (n = 7) with a total of 61 informants (51 women and 10 men). We then performed an inductive systematic analysis of the data to identify documented cognitive bias associated with the decisions of individuals to participate and remain in or abandon social programs. The interviewees were living in conditions of poverty, facing difficulties in meeting even their most basic needs including food. Program participants attached far greater weight to incentives such as the basic food basket than to the other benefits offered by the program. The four localities visited maintained traditional views of domestic roles and practices, particularly regarding child-rearing, where women were in charge of childcare, home care and food preparation. Problems linked to child malnutrition were a decisive factor in the decision of residents to participate and remain in the program. Testimonials gathered during the study demonstrated that the longer the mothers remained in the program, the more they understood and adopted the concepts promoted by the interventions. In contexts marked by economic vulnerability, it is essential that ECD programs create the necessary conditions for maximizing the benefits they offer. Our analysis suggests that cognitive load and present bias were the biases that most severely affected the decision-making capacity of beneficiaries. Therefore, considering loss aversion and improving the management of incentives can help policymakers design actions that "nudge" people into making the kinds of decisions that contribute to their well-being.

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. 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. METHODS: 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. DISCUSSION: 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. TRIAL REGISTRATION: ClinicalTrials.gov NCT04210362.

'[The pediatrician] said that maybe my milk, instead of doing good, no longer helped': the ecology of infant formula in rural communities in Central Mexico.

OBJECTIVE: As Mexico continues to develop, an epidemiological and nutritional transition has led to an increase in infant formula use in its rural and indigenous communities. Our objective was to determine the social and cultural factors that influence the use of formula in such populations in Central Mexico. DESIGN: Qualitative study using a data collection instrument based on the socio-ecological framework. SETTING: Two rural and indigenous communities in Central Mexico. PARTICIPANTS: Mothers, fathers, grandparents and healthcare providers. RESULTS: Breast-feeding was favoured in both communities; however, several cultural traditions hindered exclusive breast-feeding. As these communities became more developed, emerging ideas of modernity led to negative connotations about breast-feeding and many mothers began to view formula as a complement for breast-feeding. Formula was seen as a convenient solution for breast pain, insufficient milk and body image. Healthcare providers promoted the use of formula through their own beliefs, information, communication and conflicts of interest with formula industry representatives. The recent social and economic changes in these communities combined with the increased advertising and availability of breast milk substitutes have facilitated the preference for formula. CONCLUSIONS: Women in rural, indigenous communities in Central Mexico are increasingly using formula. Efforts at the policy and institutional levels are needed to protect mothers and their children from the detrimental consequences of unregulated formula promotion and the formula culture that it brings with it.

Arsenic methylation capacity in relation to nutrient intake and genetic polymorphisms in one-carbon metabolism.

BACKGROUND: Nutrients and genetic polymorphisms participating in one-carbon metabolism may explain interindividual differences in inorganic arsenic (iAs) methylation capacity, which in turn may account for variations in susceptibility to iAs-induced diseases. OBJECTIVES: 1) To evaluate the association between polymorphisms in five one-carbon metabolism genes (FOLH1 c.223 T > C, MTHFD1 c.1958 G > A, MTHFR c.665 C > T, MTR c.2756 A > G, and MTRR c.66 A > G) and iAs methylation capacity; 2) To assess if previously reported associations between nutrient intake and iAs methylation capacity are modified by those polymorphisms. METHODS: Women (n = 1027) exposed to iAs in Northern Mexico were interviewed. Blood and urine samples were collected. Nutrient dietary intake was estimated using a validated food frequency questionnaire. iAs methylation capacity was calculated from urinary iAs species (iAs, monomethylarsonic acid [MMA] and dimethylarsinic acid [DMA]) measured by high performance liquid chromatography (HPLC-ICP-MS). One polymorphism in each of the five genes evaluated was genotyped by allelic discrimination. Multivariable linear regression models were used to evaluate if genetic polymorphisms modified the associations between iAs methylation capacity parameters and nutrient intake. RESULTS: The median (min-max) concentration of total arsenic (TAs) was 20.2 (1.3-2776.0) µg/g creatinine in the study population. Significant interactions for iAs metabolism were only found with FOLH1 c.223 T > C polymorphism and vitamin B12 intake, so that CT and CC genotype carriers had significantly lower %iAs, and higher DMA/iAs with an increased vitamin B12 intake, as compared to carriers of wild-type TT. CONCLUSION: Differences in dietary nutrient intake and genetic variants in one-carbon metabolism may jointly influence iAs methylation capacity. Confirmation of these interactions in other populations is warranted.

CYP1A1, CYP1B1, GSTM1 and GSTT1 genetic variants and breast cancer risk in Mexican women.

OBJECTIVE: To evaluate if variants in the genes CYP1A1 (T3801C and A4889G), CYP1B1 (G119T), GSTM1 (indel) and GSTT1 (indel) are associated with breast cancer (BC) among Mexican women. MATERIALS AND METHODS: 952 incident cases with histologically confirmed BC were matched by age (± 5 years) and zone of residence with 998 healthy population controls. Genetic variants in genes CYP1A1, CYP1B1, GSTM1 and GSTT1were genotyped by allelic discrimination and multiplex PCR. In a subsample of women, 105 markers for ancestry were determined. RESULTS: An increased BC risk, independent of other BC risk factors, was observed among carriers of CYP1B1 G119T genotype (T/T vs. G/G: OR=1.9; 95%CI 1.4-2.5). CONCLUSION: Our results support the existence of genetic susceptibility for BC conferred by CYP1B1 G119T variant among Mexican women.

CYP1A1, CYP1B1, GSTM1 and GSTT1 genetic variants and breast cancer risk in Mexican women / Variantes genéticas de CYP1A1, CYP1B1, GSTM1 y GSTT1, y riesgo de cáncer mamario en mujeres mexicanas

Abstract: Objective: To evaluate if variants in the genes CYP1A1 (T3801C and A4889G), CYP1B1 (G119T), GSTM1 (indel) and GSTT1 (indel) are associated with breast cancer (BC) among Mexican women. Materials and methods: 952 incident cases with histologically confirmed BC were matched by age (± 5 years) and zone of residence with 998 healthy population controls. Genetic variants in genes CYP1A1, CYP1B1, GSTM1 and GSTT1were genotyped by allelic discrimination and multiplex PCR. In a subsample of women, 105 markers for ancestry were determined. Results: An increased BC risk, independent of other BC risk factors, was observed among carriers of CYP1B1 G119T genotype (T/T vs. G/G: OR=1.9; 95%CI 1.4-2.5). Conclusion: Our results support the existence of genetic susceptibility for BC conferred by CYP1B1 G119T variant among Mexican women.

Resumen: Objetivo: Evaluar si las variantes en los genes CYP1A1 (T3801C y A4889G), CYP1B1 (G119T), GSTM1 (indel) yGSTT1 (indel), se asocian con el cáncer de mama (CM) en mujeres mexicanas. Material y métodos: Se parearon por edad (± 5 años) y zona de residencia 952 casos incidentes de CM histológicamente confirmado con 998 controles sanos poblacionales. Se genotipificaron variantes en los genes CYP1A1, CYP1B1, GSTM1 y GSTT1 por discriminación alélica y PCR multiplex. En una submuestra de mujeres, se determinaron 105 marcadores de ancestría. Resultados: Se observó un aumento del riesgo de CM, independiente de otros factores de riesgo, entre las portadoras del genotipo CYP1B1 G119T (T/T vs. G/G: RM=1.9; 95%CI 1.4-2.5). Conclusiones: Nuestros resultados soportan la existencia de susceptibilidad genética para CM conferida por la variante CYP1B1 G119T en mujeres mexicanas.

Phthalate exposure, flavonoid consumption and breast cancer risk among Mexican women.

OBJECTIVE: To evaluate if selected phthalate exposure and flavonoid intake interact on breast cancer (BC) risk. MATERIAL AND METHODS: Interviews and urine samples were obtained from 233 women with histologically confirmed BC and 221 healthy controls matched by age and place of residence, from various states of northern Mexico. Urinary metabolites concentrations of diethyl phthalate (DEP), butyl benzyl phthalate (BBzP) and dioctyl phthalate (DOP) were determined by solid-phase extraction coupled with high-performance liquid chromatography/isotope dilution/tandem mass spectrometry. Using a semiquantitative food frequency questionnaire, consumption of five types of flavonoids (anthocyanidins, flavan-3-ols, flavanones, flavones and flavonols) was estimated according to three food groups: vegetables, fruits and legumes-oil seeds. RESULTS: A higher intake of anthocyanidins and flavan-3-ols (from vegetables), synergistically increased the negative association between BBzP and BC. No other significant flavonoid-phthalate multiplicative interactions on the risk for BC were found. CONCLUSION: The consumption of some flavonoids may interact with exposure to phthalates on the risk of BC. Epidemiological and underlying mechanisms information is still insufficient and requires further investigations.