Effects of Economic and Geographical Stressors on Home, Maternal Stress and Subsequent Infants’ Neurodevelopment: Evidence from an Indigenous Cohort Study

• In Event: Exploring Protective Factors for Indigenous Children in the Midst of Economic, Environmental, and Social Stressors

Abstract

Introduction: The cognitive and emotional stimulations that children receive at home have profound impacts on their developing brain and neurodevelopment during early years. Families’ accessibility to learning resources and opportunities, which may be restricted due to economic hardship and geographical barriers, can impact the quality of home environment. Families from rural indigenous communities experience both high rates of poverty and unemployment as well as disproportionate exposure to environmental contaminants, which are known to negatively impact children’s neurodevelopment. The goal of the current study was to evaluate the home environment and maternal stress as mechanisms explaining the associations between socioeconomic status (SES) and infants’ cognitive outcomes in a sample of mother-child pairs from an indigenous birth cohort study, while controlling for other environmental stressors.
Study Population: Participants in the current study were mother-infant pairs (N= 408) from an indigenous birth cohort study, examining the effects of exposure to metal mixtures originated from abandoned uranium mines across the tribal communities on children’s development.
Methods: Infants’ cognitive development between 9-13 months was assessed using mothers’ reports on communication and problem-solving questionnaires of the Ages and Stages Questionnaire Inventory during home visits conducted by research field staff. Mothers also reported on their provision of cognitive and emotional stimulation at home using the Home Observation Measurement of the Environment (HOME), and their stress level using the Perceived Stress Scale. Along with families’ residential proximity to abandoned uranium mines (AUMs), the geographical isolation was estimated using the American Community Survey and the LandScan datasets, respectively. Multivariable regressions were estimated to examine the effects of multiple exposure variables (i.e., SES, geographical isolation, proximity to AUMs, maternal stress and HOME) on infants’ cognitive development. Further, causal mediation analyses were conducted to estimate the effects of family-SES on children’s cognitive development mediated by maternal perceived stress and HOME, while controlling for infant sex, proximity to mines, and geographical isolation.
Results: More than half of the children came from families with an annual income of less than $20,000 and had mothers with high school or below education and unemployed. Problem-solving skills were higher among children of mothers with education above high school. The home environment had significant positive association with both communication and problem-solving skills (βs = 2.23 and 1.95, 95% CIs: 1.49, 2.97 and 0.89, 3.01), whereas maternal stress was negatively associated with the home environment (β = -.22, 95% CI: -.32, -.12). Geographical isolation and proximity to AUMs were unrelated to child outcomes, but geographical isolation was negatively related to HOME scores (β = -.09, 95% CI: -0.11, -0.07). Mediation analyses revealed that HOME mediated most of the effect of SES on infants’ communication and problem-solving skills (88% and 36% mediated respectively). There was no significant mediation effect of maternal perceived stress on any measure of infants’ cognitive development.
Conclusions: Our results suggest that efforts to enrich the home environment can buffer against the negative impacts of combined environmental, social and geographical risk factors, common in and unique to rural indigenous communities, on children’s cognitive development.

Authors

• Sara Nozadi, University of New Mexico
  Presenting Author

• Deborah Kanda

• Li Luo, University of New Mexico

• Daniel Beene

• Debra MacKenzie

• Johnnye Lewis