Adrenocortical and behavioral attunement in parents with 1-year-old infants

Sethre-Hofstad et al. [2002, Psychoneuroendocrinology 27:731-747] found that behaviorally well-attuned or sensitive parents showed better physiological attunement with their 2- to 4-year-old toddlers' adrenocortical responses to a potentially challenging task than less sensitive parents. In the present study we aimed to replicate this finding in a sample of 83 parents with 15-month-old infants. Parental and infant cortisol responses were assessed using saliva samples collected before and 21 min after the child's confrontation with a stranger and a moving robot. Infant behaviors reflecting distress/uncertainty during the stranger-robot session were rated from videotape. Parental sensitivity was observed during a parent-infant teaching episode. Our findings replicate those of Sethre-Hofstad et al. [2002, Psychoneuroendocrinology 27:731-747] by showing correlated parent-infant cortisol responses for sensitive parents but not for less sensitive parents. Furthermore, sensitive parents cortisol responses were associated with their children's distress/uncertainty during the stranger-robot episode, whereas this was not true for less sensitive parents. Results indicate an important connection between behavior and physiology in parent-infant interactions that deserve more research.     

Outcomes of early parent‐child adrenocortical attunement in the high‐risk offspring of depressed parents

This study examined the impact of parent‐child attunement of morning cortisol on parenting and child outcomes in dyads with and without parental depression. Participants included 142 parent‐child dyads (3–5 years‐old) who provided morning cortisol samples at Wave 1, and 98 dyads returned for the 3‐year follow‐up at Wave 2. Results indicated that for parents with a history of depression and for female children, stronger attunement predicted increases in parental hostility from Wave 1 to Wave 2. For females only, stronger attunement was related to children's depressive symptoms at Wave 1 and Wave 2. Stronger attunement was also associated with increases in children's depressive symptoms from Wave 1 to Wave 2, poorer psychosocial functioning at Wave 1, and ADHD symptoms at Wave 2. Findings highlight attunement as an important biological process related to parenting and child outcomes and suggest it may play a role in the intergenerational transmission of depression risk.     

Maternal depression and infant daytime cortisol

The effect of maternal depressive disorder on infant daytime cortisol production was studied in three groups of infants; one group with mothers with comorbid depression and anxiety (n = 19), a second group with mothers with depression only (n = 7), and a third group with non‐depressed mothers (n = 24). The infants' cortisol production pattern was measured when they were 6, 12, and 18 months old in combination with repeated measures of parenting stress and depression symptoms. Multilevel modeling analyses showed that infants of mothers with comorbid depression and anxiety had relatively higher cortisol production from morning to bedtime and higher bedtime values as compared to infants of non‐depressed mothers and infants of depressed only mothers when they were 6 and 12 months old, but not when 18 months old. The results were interpreted in light of possible changes in the infants' stress regulatory capacities or changes in maternal coping strategies at infant age 18 months. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 334–351, 2013     

Maternal behavior and maternal stress are associated with infant behavioral development in macaques

The simultaneous effects of naturally occurring individual differences in maternal care and maternal peripartum stress on infant development have been sparsely reported in nonhuman primates. In this work, we used a comparative approach to assess how changes in peripartum maternal excreted cortisol levels and the quality of mother-infant interactions correlate with infant behavioral development in group-living rhesus and Japanese macaques. We tested the hypothesis that peripartum maternal stress was associated with infant behavioral characteristics during development. Due to the difference in mothering style between the two species, we provided separated analyses for two groups. A sample of mother-infant pairs (Japanese macaques, N = 14; rhesus macaques, N = 10) was observed during the first 3 months of the infant's life. Follow-up observations (at 5, 7, and 9 months of age) were collected for the infants. Maternal cortisol levels were measured during the peripartum period. We found preliminary evidence that maternal peripartum stress and differences in key components of maternal behavior are associated with infant behavior throughout the developmental phase. We also provided a working hypothesis regarding maternal behavior and maternal stress as factors playing unique roles in different components of infant behavioral development.     

Maternal expressive suppression moderates the relations between maternal and child hair cortisol

Self-reports and physiological indicators of stress such as cortisol levels are correlated in maternal and child samples. This relationship is likely to be influenced by maternal emotion regulation. Herein, we investigate the moderating role of maternal regulation strategies on the association between maternal and child hair cortisol levels. Mother–child dyads (N = 63, child mean age = 49.74 months) participated in the study. Hair samples were collected from mother and child, and cortisol was assayed. Mothers reported on their own emotion regulation strategies, namely expressive suppression and cognitive reappraisal. As expected, mother and child hair cortisol levels were significantly correlated. Interestingly, the relation between maternal and child hair cortisol was moderated by maternal suppression of emotion. Mother and child hair cortisol levels were related at low levels of maternal suppression, but not at higher levels of suppression. Maternal cognitive reappraisal of emotion was not associated with cortisol levels.     

Socioeconomic risk moderates the association between caregiver cortisol levels and infant cortisol reactivity to emotion induction at 24 months

Relations between maternal baseline cortisol and infant cortisol reactivity to an emotion induction procedure at child ages 7, 15, and 24 months were analyzed using data from the Family Life Project (N = 1,292). The emotion induction consisted of a series of standardized and validated tasks, including an arm restraint, toy removal, and mask presentation, intended to elicit responses of fear and frustration. Results revealed that at 7 and 15 months, maternal baseline cortisol was negatively related to child cortisol reactivity, such that children of mothers with lower cortisol exhibited steeper cortisol increases in response to the emotion induction. At 24 months, the association between mother and infant cortisol was moderated by socioeconomic risk, such that maternal baseline cortisol was associated with child cortisol reactivity only in dyads characterized by low socioeconomic risk. Furthermore, at 24 months, children of mothers with low baseline cortisol and low socioeconomic risk exhibited decreasing cortisol responses, whereas children of mothers with low baseline cortisol but high risk exhibited flat cortisol responses. Children in dyads characterized by high baseline maternal cortisol also exhibited flat cortisol responses regardless of socioeconomic risk. The role of caregiver physiology in the regulation of the child's stress response in the context of adversity is discussed.     

Neuroendocrine and immune markers of maternal stress during pregnancy and infant cognitive development

Antenatal exposure to maternal stress is a factor that may impact on offspring cognitive development. While some evidence exists of an association between maternal antenatal depressive or anxiety symptoms and infants' cognitive outcomes, less is known about the role of biological indices of maternal antenatal stress in relation to infant cognitive development. The current study investigated the association between maternal depressive and anxiety symptoms, stress and inflammatory markers during pregnancy and infant's cognitive development in a sample of 104 healthy pregnant women (mean gestational age = 34.76; SD = 1.12) and their 12-week-old infants (mean postnatal weeks = 11.96; SD = 1.85). Maternal depressive and anxiety symptoms were evaluated during pregnancy, alongside measurements of serum Interleukin-6 (IL-6), C-Reactive Protein (CRP), salivary cortisol, and alpha amylase (sAA) concentrations. Infant cognitive development, maternal caregiving and concurrent anxiety or depressive symptoms were assessed 12 weeks after delivery. Hierarchical linear regressions indicated that higher maternal diurnal cortisol and CRP levels were independently associated with lower infant cognitive development scores, while adjusting for infant gender and gestational age, maternal IQ, caregiving, depressive, or anxiety symptoms. Though correlational, findings seem suggestive of a role for variation in maternal biological stress signals during pregnancy in influencing infants' early cognitive development.     

Assessment of exposure to organochlorine pesticides and levels of DNA damage in mother–infant pairs of an agrarian community

Exposure to organochlorine pesticides was studied in a group of mother–infant pairs living in a rural area where agriculture is the main economic activity. Fumigation in this zone is performed with airplanes, thus affecting the inhabited areas around them, including schools. Heparinized venous blood of mothers and umbilical cords was used to evaluate the olive tail moment in the comet assay, and micronuclei, chromatin buds, and nucleoplasmic bridges in peripheral blood lymphocytes. Cord blood samples were taken at the moment of birth only from natural and normal parturitions. Determinations of hexachlorobenzene, aldrin, heptachlor epoxide, oxichlordane, t and c‐chlordane, cis‐nonachlor, mirex, alpha and beta‐endosulfan, alpha, beta and gamma hexachlorocyclohexane, and p'p'‐DDT, p'p'‐DDE were conducted to establish the differential distribution of the toxicants between compartments, i.e., mother and umbilical cord. Significantly higher pesticide levels were found in umbilical cord plasma than in mothers' plasma for almost all compounds tested, except DDE and oxychlordane. Significantly higher olive tail moments were found in umbilical cords than in mothers, whereas micronuclei frequencies were higher in mothers than in umbilical cords. However, neither the levels of micronuclei nor the olive tail moment were correlated with pesticide levels. Given that no other exposure to toxic compounds has been identified in this region, the lack of correlation between genotoxicity biomarkers and pesticide levels may be due to the variability of the exposure and to endogenous processes related to lipid mobility during pregnancy, the metabolism of the compounds, and individual susceptibilities. Environ. Mol. Mutagen., 2013. © 2013 Wiley Periodicals, Inc.