Differential influences of early growth and social factors on young children's cognitive performance in four low-and-middle-income birth cohorts (Brazil, Guatemala, Philippines, and South Africa)

Predictors of early child development for screening pregnant women most in need of support in Brazil

Background

Home visiting programmes can support child development and reduce inequalities, but failure to identify the most vulnerable families can undermine such efforts. We examined whether there are strong predictors of poor child development that could be used to screen pregnant women in primary health care settings to target early interventions in a Brazilian population. Considering selected predictors, we assessed coverage and focus of a large-scale home visiting programme named Primeira Infância Melhor (PIM).

Methods

We undertook a prospective cohort study on 3603 children whom we followed from gestation to age four years. We then used 27 potential socioeconomic, psychosocial, and clinical risk factors measurable during pregnancy to predict child development, which was assessed by the Battelle Developmental Inventory (BDI) at the age of four years. We compared the results from a Bonferroni-adjusted conditional inference tree with exploratory linear regression and principal component analysis (PCA), and we conducted external validation using data from a second cohort from the same population. Lastly, we assessed PIM coverage and focus by linking 2015 cohort data with PIM databases.

Results

The decision tree analyses identified maternal schooling as the most important variable for predicting BDI, followed by paternal schooling. Based on these variables, a group of 214 children who had the lowest mean BDI (BDI = -0.48; 95% confidence interval (CI) = -0.63, -0.33) was defined by mothers with ≤5 years and fathers with ≤4 years of schooling. Maternal and paternal schooling were also the strongest predictors in the exploratory analysis using regression and PCA, showing linear associations with the outcome. However, their capacity to explain outcome variance was low, with an adjusted R2 of 5.3% and an area under the receiver operating characteristic curve of 0.62 (95% CI = 0.60, 0.64). External validation showed consistent results. We also provided an online screening tool using parental schooling data to support programme's targeting. PIM coverage during pregnancy was low, but the focus was adequate, especially among families with longer enrolment, indicating families most in need received higher dosage.

Conclusions

Information on maternal and paternal schooling can improve the focus of home visiting programmes if used for initial population-level screening of pregnant women in Brazil. However, enrolment decisions require complementary information on parental resources and direct interactions with families to jointly decide on inclusion.

Women's health and well-being in five birth cohorts from low- and middle-income countries: Domains and their associations with early-life conditions

Background

Women's health and well-being (WHW) have been receiving growing attention, but limited progress has been made on how to measure its different domains in low- and middle-income countries (LMICs). We used data from five long-term birth cohorts in Brazil, Guatemala, the Philippines and South Africa to explore different domains of adult WHW, and how these domains relate to early life exposures.

Methods

Based upon an a priori conceptualisation of eight postulated WHW outcomes available in the data, we grouped them as follows: human capital (intelligence quotient, schooling, height, and teenage childbearing), metabolic health (body mass index and metabolic syndrome score), and psychological (happiness and Self-Reported Questionnaire (SRQ) scores). Correlation analyses confirmed the variables theoretically belonging to the same dimension of WHW were statistically related. We then applied principal component analysis to each group of variables separately and used the first principal component as a summary quantitative measure of the corresponding WHW dimension. Finally, we assessed the association of each domain with a range of early-life factors: wealth, maternal education, maternal height, water, and sanitation, birthweight, length at two years and development quotient in mid-childhood.

Results

The three domains were largely uncorrelated. Early determinants were positively associated with human capital, while birth order was negatively associated. Fewer associations were found for the metabolic or psychological components. Birthweight and weight at age two years were inversely associated with metabolic health. Maternal education was associated with better psychological health.

Conclusions

Our findings indicate that WHW is multidimensional, with most women in the cohorts being compromised in one or more domains while few women scored highly in all three domains. Our analyses are limited by lack of data on adolescent exposures and on other relevant WHW dimensions such as safety, agency, empowerment, and violence. Further research is needed in LMICs for identifying and measuring the multiple domains of WHW.

The Shared Pleasure Paradigm: A study in an observational birth cohort in South Africa

Mother-infant dyads in low- and middle-income countries (LMICs) may be exposed to a range of factors associated with suboptimal development. Optimal infant development is likely supported by synchronicity in the early mother-infant relationship, but limited corroborative research is available in LMICs. The Drakenstein Child Health Study (DCHS) provided an opportunity to study this synchronicity and its associations in South Africa. A South African birth cohort study investigating early-life determinants of child health in a LMIC context provided participants. The Shared Pleasure (SP) paradigm helped assess early mother-infant synchronicity in videos of a sub-set of 291 mother-infant dyads at their 14-week well baby visit. General linear regression models investigated the relationship between selected maternal and infant characteristics and the presence of Shared Pleasure moments. Out of a possible 291 dyads, 82% (n = 239) yielded Shared Pleasure moments. The mean age of mothers was 27 years, while infant sex distribution comprised 54% females and 46% males. The shortest single Shared Pleasure moment lasted at least 0.5 s and the longest 28 s. Shared Pleasure moments were associated with higher gestation age at delivery (p = 0.008) and higher infant birth weight (p = 0.006), but were not related to mother's mental health and infant health outcomes at 14 weeks. The high frequency of positive Shared Pleasure moments in reciprocal dyadic interactions in this sample suggests that significant disruption in shared pleasure may be present only in extreme cases (e.g. mothers with severe mental disorders). Further work is needed to investigate the mechanisms underlying the associations between early mother-infant synchronicity and better outcomes noted here, and to assess whether SP may serve as a culturally appropriate screen for assessing connectedness.

Maternal Shared Pleasure, Infant Withdrawal, and Developmental Outcomes in a High Risk Setting in South Africa

Background: Infants in lower middle income countries are often exposed to early adversities which may lead to suboptimal caregiving environments and place them at risk of not achieving their developmental potential. Synchrony and positive engagement in the mother-infant relationship plays a critical role in buffering the impact of early adversity. Shared Pleasure (SP) is considered a marker of high intensity positive interaction and may hold a promise of improving developmental outcomes. Methods: This study was part of a prospective observational study of mothers with and without mental illness in South Africa. Dyadic videos were assessed for SP and infant withdrawal (using the Alarm Distress Baby Scale) at 6 months. Infant developmental outcomes were assessed using the Bayley's Scales for Infant and Toddler Development, third edition at 18 months. Results: Ninety-one dyads were assessed for SP. The occurrence of SP was low (20%). There was no significant association with an EPDS measure of maternal depression (p = 0.571) and SP moments. Infant withdrawal was high (72%) and associated with male infant gender (p = 0.025). There was a significant association between the occurrence of SP and a lower score of infant withdrawal (estimate = -1.29; SE = 0.4; p = 0.0002). The number of SP moments at 6 months was significantly associated with motor (estimate = 2.4; SE = 0.9; p = 0.007) and marginally significant with cognitive scores (estimate = 1.9; SE = 1.0; p = 0.052) at 18 months. Regression modelling differential outcomes showed a greater improvement in cognitive scores at 18 months in infants with an SP moment compared to those without an SP moment [SP average difference (AD) = 7.4 (2.4), no SP AD = 10.4 (1.2); p = 0.012]. Infants without an SP moment experienced a larger decrease in motor scores at 18 months compared to those with an SP moment [SP AD = -3 (3.0); no SP AD = -10.6 (1.5), p = 0.027]. Conclusion: While the occurrence of SP in this sample was low and the rates of infant withdrawal were high, there were promising results suggesting early positive SP interactions may contribute to improvements in subsequent developmental outcomes.