Cross-sectional and prospective studies have provided evidence of the neurotoxic effect of early exposure to fluoride (F) in pregnancy. It has been negatively associated with cognitive development during childhood, with most research conducted in areas with high F levels in community drinking water (CDW). Data from 316 to 248 mother-child pairs from the Infancia y Medio Ambiente (Childhood and Environment, INMA) birth cohort project with maternal urinary F level adjusted for creatinine (MUFcr) measurements in the first and third trimesters of pregnancy. Children's cognitive domains and intelligence indexes were evaluated using the Bayley Scales (age of 1) and the McCarthy Scales (age of 4). Multiple linear regression analyses were carried out adjusting for a wide range of covariates related to the child, mother, family context and other potential neurotoxicants. No association was found between MUFcr levels and Bayley Mental Development Index score. Nevertheless, regarding the McCarthy scales, it was found that per unit (mg/g) of MUFcr across the whole pregnancy, scores in boys were greater for the verbal, performance, numeric and memory domains (β = 13.86, CI 95%: 3.91, 23.82), (β = 5.86, CI 95%: 0.32, 11.39), (β = 6.22, CI 95%: 0.65, 11.79) and (β = 11.63, CI 95%: 2.62, 20.63) respectively and for General Cognitive Index (β = 15.4, CI 95%: 6.32, 24.48). For girls there was not any cognitive score significantly associated with MUFcr, being the sex-F interactions significant (P interaction <0.05). Including other toxicants levels, quality of family context or deprivation index did not substantially change the results. In boys, positive associations were observed between MUFcr and scores in cognitive domains at the age of 4. These findings are inconsistent with those from some previous studies and indicate the need for other population-based studies to confirm or overturn these results at low levels of F in CDW.

Socioeconomic position (SEP) may have different effects on cognitive development and family context could play a role in this association. This work aimed to analyse the role of socioeconomic positions, measured via various indicators collected longitudinally, in cognitive development at 7–11 years of age, evaluating the role of family context as a potential mediator. The study sample included 394 and 382 children from the INMA Gipuzkoa and Valencia cohorts, respectively. SEP indicators were assessed during pregnancy (family social class, parental education, employment, and disposable income) and at 7 (Gipuzkoa) and 11 (Valencia) years of age (At Risk of Poverty or Social Exclusion (AROPE)). Family context and cognitive development were measured with the Haezi-Etxadi Family Assessment Scale 7–11 (HEFAS 7–11) and Raven’s Coloured Progressive Matrices (Raven’s CPM), respectively. Linear regression models were developed to assess the relationships between (a) SEP-family context, (b) SEP-cognitive development, and (c) family context-cognitive development, adjusting for a priori-selected confounders. Simple and multiple mediation analyses were performed to explore the role of family context in the SEP-cognitive development relationship. Lower SEP was related with a lower cognitive score, this association being particularly robust for family social class. SEP indicators were related to subscales of family context, in particular those regarding cognitive stimulation, parental stress, and parenting. A relationship was also found between these three subscales and child cognitive development, mediating the effect of family social class on child cognition by 5.2, 5.5, and 10.8%, respectively, and 12.0% jointly.    Conclusion: Both family SEP and context contribute to a child’s cognitive development. Equalising policies and positive parenting programmes could contribute to improving cognitive development in children. What is Known:• Parental social class, education, and employment status have been widely employed to measure socioeconomic position. What is New:• This work focuses on standard measurements of socioeconomic position but also other economic indicators such as the EHII and AROPE, and their effect on child cognitive development and family context.• Promotion of cognitive and linguistic development, parental stress and conflict, and parental profile fostering child development mediated the effect of family social class on cognitive development.

This study analyzes the influence of socioeconomic status, quality of family context and sibling status on cognitive development in a sample of 551 five‐year‐old children. The regression analyses confirmed the predictive value of socioeconomic status and quality of family context on cognitive development. The quality of family context mediates the relation between socioeconomic status and cognitive development. None of the variables relating to the sibling group showed a significant relationship with cognitive development.

This paper makes a proposal for the comprehensive assessment of the family context of children aged two years. It offers an updated resource based on recent research into the assessment of family contexts and their influence on children's psychological development. The proposal explores the following areas: Presence of learning materials; Potential for play; Stimulation of cognitive development; Stimulation of language development; Emotional expressiveness; Setting of limits and optimal frustration; Enhancement of self-esteem and autonomy; Observation of mother–child interactions; Father's involvement; Quality of non-parental care; Relations with the extended family and social support network; Stability of the child's social relationships; Relations with the school; Diversity of experiences; Absence of exposure to conflict; Absence of parental stress; and Quality of the physical context. The areas explored are grouped into three blocks: Stimulation of cognitive and linguistic development; Stimulation of socio-emotional development; and Organisation of the social context and physical environment.