Early childhood stress responses to psychosocial stressors: The state of the science.

The aim of this systematic review was to better understand whether and to what extent psychosocial stressors are associated with hypothalamic-pituitary-adrenal axis or autonomic nervous system stress responses in young children (1-6 years of age). Studies were classified by psychosocial stressors from the ecobiodevelopmental model: social and economic resources, maternal mental health, parent-child relationships, and the physical environment. Of the 2388 identified studies, 32 met full inclusion criteria, including over 9107 children. Child physiologic stress responses were measured as hair and urinary cortisol and cortisone, salivary diurnal and reactive cortisol, salivary reactive alpha-amylase, and respiratory sinus arrhythmia. There were 107 identified relations between psychosocial stressors and physiologic stress responses. Nearly two thirds of these relations suggested that children have dysregulated stress responses as either significantly blunted (n = 27) or increased (n = 37); 43 relations were not significant. Children most consistently had significantly dysregulated stress responses if they experienced postnatal maternal depression or anxiety. Some reasons for the mixed findings may be related to characteristics of the child (i.e., moderators) or stressor, how the stress response or psychosocial stressor was measured, unmeasured variables (e.g., caregiving buffering), researcher degrees of freedom, or publication bias.

Relationships among caregiving, stress, and self-regulation in toddlers living in poverty.

PURPOSE: The Developmental Psychobiological Model of Experiential Canalization (DPMEC) proposes that conditions of poverty-related adversity influence child self-regulation through parental caregiving, stress hormones, and the child's genetics. However, empirical findings investigating these relationships with prolonged stress hormones are mixed. Further, the relationships among conditions of adversity with prolonged stress hormones have seldom been investigated in toddlers living in poverty. Guided by the DPMEC, we examined the relationships among maternal caregiving, prolonged stress, and self-regulation in toddlers living in poverty in the United States, to include examining whether toddler prolonged stress mediated relations between maternal caregiving and child self-regulation. DESIGN AND METHODS: Participants were mothers and toddlers (20 to 24 months of age) living in poverty, who provided hair samples to measure four months of average cortisol concentration to estimate prolonged stress. We used observational measures to examine maternal caregiving and indirect report to measure children's self-regulation. RESULTS: Findings did not support the role of toddler prolonged stress in mediating the relationship between maternal caregiving and toddler self-regulation. However, multiple linear regression models showed that higher levels of maternal emotionally supportive caregiving significantly predicted better toddler soothability (b = 0.90; p = .03; 95% CI [0.10, 1.69]; partial correlation = 0.26). CONCLUSIONS: This study adds partial support for the DPMEC to represent associations between maternal caregiving and toddler self-regulation for mothers and toddlers experiencing poverty. PRACTICE IMPLICATIONS: While these data come from an observational study, pediatric nurses may consider assessing maternal supportive caregiving upon reports of poor toddler soothability.

Temperament and sleep behaviors in infants and toddlers living in low-income homes.

Temperament is a dynamic trait that can be shaped by maturity and environmental experiences. In this study, we sought to determine whether and the extent to which temperament was predicted by sleeping behaviors in an understudied sample of primarily Black and White infants and toddlers living in low-income homes (N = 150). Sleeping behaviors were assessed at 15-19 months of age with caregiver report of the Tayside Children's Sleep Questionnaire. Temperament was examined as effortful control, negativity, and surgency with the Infant Behavior Questionnaire Very Short Form at 9-12 months of age and with the Early Childhood Behavior Questionnaire Short Form at 20-24 months of age. Covariates were maternal education, household income, and child sex and race. Continuous variables were standardized, then missing data from independent variables were multiply imputed in 20 datasets. Regression analyses showed that about 1 SD improvement in toddler sleep behaviors significantly predicted about 1/5 SD better toddler effortful control. However, sleep behaviors did not significantly predict toddler surgency or negative affect. This study shows that for a sample of infants and toddlers in low-income homes, how a child learns to regulate sleeping behaviors may influence the development of overall effortful control about six months later.

Sociodemographics and chronic stress in mother-toddler dyads living in poverty.

Experiencing chronic stress early in life is associated with later health disparities, and poverty may be a significant stressor for both mothers and children. With a sample of primarily Black and White mothers (N = 75) and toddlers (N = 71) living in poverty in the United States, we examined the direct relations between sociodemographic conditions of poverty and chronic physiological stress. Mothers completed questionnaires on sociodemographics, including mother/toddler race, mother's education, father's education, poverty level, economic hardship, marital status, unemployment status, and toddler sex. Physiological chronic stress was measured by assaying the cortisol content of 4 cm samples of hair cut from the posterior vertex of mothers and toddlers (20-24 months of age) to represent 4 months of stress. Mothers' and toddlers' chronic stress was significantly, moderately, and positively associated. Toddlers had a trending relationship of moderately higher chronic stress if they were Black compared to not Black. Mothers had significantly, moderately higher chronic stress if they were Black or had a Black toddler (compared to not Black), not married (compared to married), or were working (compared to not working). The findings suggest that these mothers, simultaneously navigating poverty and parenting a toddler, need resources to reduce chronic stress.

Co-occurring risk and protective factors and regulatory behavior of infants living in low-income homes.

Early self-regulation is a foundation for lifelong wellness and can be shaped by the interplay among several vital exposures. In this study, we examined the emergence of reliable profiles based upon exposure to risk and protective factors in infancy, determined if sociodemographic resources predict profile membership, and determined if these profiles predict early regulatory behaviors in a sample of infants reared in low-income homes. Data were collected from a sample of primarily Black or White mother-infant dyads living in low-income homes in the Midwest (n = 222) during the infants' first year of life (mean maternal age at enrollment: 26.29 years; range 18-43 years). Exposures included mother-infant interactions; father support; maternal depression, stress, and self-efficacy; home environment; food security; and breastfeeding duration. Sociodemographic resources included poverty status; economic hardship; maternal education, employment, and age; parental marital status; and infant race and sex. Infant regulatory behaviors were measured with the Infant Behavior Questionnaire-Revised Very Short Form effortful control subscale (mean age 11 months; range 8.5-14.3 months). Latent profile analysis was used to profile infants by risk and protective exposures. Regression was used to differentiate profiles by sociodemographic resources and to predict infant regulatory behavior from profiles. Three profiles emerged: low father support, good maternal mental health, and poor maternal mental health. A married mother, less economic hardship, and working mothers predicted infant exposure to good maternal mental health. Infant regulatory behavior was best when the infant was exposed to the good maternal mental health profile. Implications for future research are discussed.

Maternal Mental Health Symptoms and Clusters Predict Toddler Sleep in Low-Income Homes.

The authors examined the association of maternal mental health symptoms and symptom clusters with the sleeping behaviors of toddlers living in low-income homes. The sample is comprised of 174 racially diverse mother and toddler (15-19 months old) dyads who were participating in a longitudinal birth cohort study. Dyads were initially recruited from Women, Infant, and Children clinics in a Midwestern county of the United States. Maternal mental health symptoms were measured with self-reports of depression (Center for Epidemiological Studies-Depression), parenting stress (Parenting Stress Index Very Short Form), and parenting self-efficacy. Toddler sleeping behaviors were measured with an adaptation of the Tayside Children's Sleep Questionnaire that assessed toddler difficulties in initiating or maintaining sleep (DIMS). Maternal mental health symptom clusters were identified with latent profile analysis and toddler DIMS were regressed on maternal mental health symptoms. We found that 1 SD worse maternal depression, parenting stress, or parenting self-efficacy predicted 0.18-0.24 SD worse toddler DIMS (p < .05). Moreover, we found that the cluster of adverse maternal mental health symptoms predicted nearly 0.75 SD worse toddler DIMS as compared with the cluster of good maternal mental health symptoms (p < .05). These findings provide insight into how maternal mental health symptom clusters may be important in understanding sleep behaviors in early toddlerhood, a sensitive period of sleep development, and underscore the need to support mothers with co-occurring adverse mental health symptoms, as their children may be at higher risk for DIMS.

Media exposure and language for toddlers from low-income homes.

In the current study, we examined whether the quantity of toddlers' exposure to media was related to language skills and whether meeting the American Association of Pediatrics (AAP) recommendations of limiting media exposure to one hour or less per day was related to language skills. We examined these associations in a sample of toddlers (N = 157) living in low-income homes. Toddlers were about two years of age (M = 28.44 months, SD = 1.48 months) during the first visit when parents reported on toddlers' exposure to media in the home. Toddlers were about three years of age (M = 33.61 months, SD = 1.06 months) during the second visit when direct measures of toddlers' expressive and receptive language and receptive vocabulary skills were completed. Controls were child gender, race, mothers' education, marital status, work status, and center-based child care. Results indicated that more frequent exposure to media was related to lower expressive language, but not receptive language or receptive vocabulary. The predictor of AAP recommendation was not significantly related to any child language outcomes. These results suggest that media exposure may be related to the displacement of language-enhancing activities during a critical time for toddlers' language development. However, the AAP media recommendation of one hour may not be related to language development.

Sleep and stress in mother-toddler dyads living in low-income homes.

Optimal sleeping behaviors are critical for overall development, yet some evidence suggests stress and living in a low-income environment are associated with disruptions of sleeping behaviors early in life. In this study, we investigated the association of toddler sleeping behaviors, particularly difficulties initiating and/or maintaining sleep (DIMS), and maternal and toddler prolonged stress using hair cortisol from dyads living in low-income homes. Hair cortisol was mainly sampled at the posterior vertex of mothers and toddlers (age 20-24 months) and analyzed with immunoassay (n = 94). Toddler DIMS were assessed at 15-19 and 27-31 months of age through mother-rated reports using the Tayside Children's Sleep Questionnaire. We found no associations between toddler DIMS and maternal stress. Additionally, early DIMS did not predict toddler stress. However, while controlling for early DIMS and sociodemographic factors, we found that higher toddler stress predicted greater DIMS in later toddlerhood (b = -2.28, SE = 0.98, p = .02, ds  = 0.64). These study findings highlight the importance of understanding the role of early life stress on later sleep patterns.

Hair sampling for cortisol analysis with mother-toddler dyads living in low-income homes.

BACKGROUND: A first step to advance stress science research in young children is understanding the relationship between chronic stress in a mother and chronic stress in her child. One non-invasive measure of chronic stress is hair cortisol. However, little is known about strategies for hair sampling in mother-toddler dyads living in low-income homes in the U.S. To address prior limitations, the purpose of this study was to understand the feasibility of sampling hair for cortisol analysis in mother-toddler dyads living in low-income homes in the U.S. We examined feasibility related to participation, eligibility, and gathering an adequate hair sample weight. METHODS: We approached 142 low-income, racially diverse, urban-dwelling mothers who were participating in an ongoing longitudinal birth cohort study for informed consent to cut approximately 150 hairs from the posterior vertex of their scalp and their toddlers' (20-24 months) scalp. We demonstrated the process of sampling hair with a hairstyling doll during home visits to the mother and toddler using rounded-end thinning shears. RESULTS: Overall, 94 of 142 mother-toddler dyads (66 %) participated in hair sampling. The most common reason for participation refusal was related to hairstyle. All but three hair samples were of adequate weight for cortisol extraction. DISCUSSION: The findings from this study can help researchers address sampling feasibility concerns in hair for cortisol analysis research in mother-toddler dyads living in low-income homes in the U.S.

Relations of Maternal Depression and Parenting Self-Efficacy to the Self-Regulation of Infants in Low-Income Homes.

There is increasing recognition that young children's self-regulation provides a foundation for overall wellness later in life. Yet, infants reared in poverty may exhibit less-developed self-regulation compared to their more advantaged peers. Factors associated with poverty that may influence early self-regulation include maternal depression and parenting self-efficacy. However, few researchers have examined how both parenting self-efficacy and maternal depression may affect young children's self-regulation. The purpose of this study was to investigate the associations among maternal depression, parenting self-efficacy, and infant self-regulation for a racially diverse sample of 142 mother-infant dyads living in low-income households in the United States. Maternal depressive symptomatology was determined with the Edinburgh Postnatal Depressive Scale. Parenting self-efficacy was determined with a self-report measure, reflecting caregivers' mindset or feelings reflecting competency as a parent of an infant. Infant self-regulation was measured by parental report of the Infant Behavior Questionnaire Short Form Effortful Control subscale. While maternal depressive symptomatology and self-efficacy were directly and significantly correlated with infant self-regulation, results of a mediation model suggested that parenting self-efficacy mediated the relationship between maternal depressive symptomatology and infant self-regulation. Lower maternal depressive symptomatology predicted better parenting self-efficacy, in turn predicting better infant self-regulation. This study increases our understanding of how early factors shape the self-regulation of infants reared in low-income homes - highlighting the potential role of targeting parenting self-efficacy for parenting interventions for mothers experiencing depressive symptoms.

Nursing Across the Lifespan: Implications of Lifecourse Theory for Nursing Research.

Despite the lifecourse focus of nursing clinical care, nursing research largely remains cross-sectional or process-oriented within silos determined by patient characteristics such as age, acuity, or disease process. Incorporating interdisciplinary lifecourse theory into pediatric nursing research provides the opportunity to expand nursing theories and research beyond practice, age, and disease silos. One such theory is the Lifecourse Health Development (LCHD) framework. LCHD takes a more expansive view of health development from preconception through old age based on the premise that health is a consequence of transactions between genetic, biological, behavioral, social, and economic contexts that change as a child develops over time (Halfon & Hochstein, 2002). LCHD also explains how intergenerational influences and prevention during early life help predict health development and disease over the lifespan. The preventive and lifecourse focus of LCHD is well-aligned with the lifespan wellness foci of pediatric nurses. The purpose of this article is to introduce pediatric nurse researchers to LCHD and discuss proposed augmentations and implications related to expanding LCHD into pediatric nursing research.