Early childhood stress regulation in out-of-home childcare and in at-home parental care – Associations with child temperament and age – The FinnBrain Birth Cohort Study

Prior research suggests that attendance in out-of-home childcare has many positive effects on child development. Despite the advantages, earlier studies also show that children present with higher cortisol levels in out-of-home childcare day when compared to days spent at home. However, only few studies have followed up the same children longitudinally. Furthermore, earlier studies have not included a comparison group of children, who were cared for at home. This study aimed at comparing children’s diurnal saliva cortisol output in outof-home childcare and in at-home parental care settings at the child age of 2 and 3.5 years old. Furthermore, the aim was to examine whether child temperament would moderate the associations between the childcare context and diurnal cortisol production. The participants were recruited from the FinnBrain Birth Cohort Study. The results showed that at the age of 2 years, the children presented with higher cortisol levels in at-home parental care when compared to the out-of-home childcare setting. However, these differences no longer appeared, as the children developed and reached the age of 3.5 years. When investigating the diurnal cortisol profiles, the results suggested higher afternoon cortisol levels in the out-of-home childcare group during the childcare day when compared to days spent at home. This difference appeared both at the age of 2 and 3.5 years old. Furthermore, temperamental surgency was associated with higher total diurnal cortisol production across the childcare settings. However, the association between surgency and diurnal cortisol production diminished along with the child age from 2 to 3.5 years of age. These findings have implications for understanding the periods of sensitivity in early childhood stress regulation and associations between temperament and cortisol output in different childcare settings.Varhaislapsuuden stressinsäätely kotona ja varhaiskasvatuksessa – yhteydet lapsen temperamenttiin ja ikään – FinnBrain Syntymäkohorttitutkimus Aiemmat tutkimukset osoittavat, että päiväkodin varhaiskasvatus hyödyttää lapsia monin eri tavoin. Siitä huolimatta tutkimuksissa on havaittu, että kodin ulkopuolinen hoitoympäristö voi nostaa lasten kortisolihormonitasoja. Aiheesta ei ole juurikaan pitkittäistutkimusta, eivätkä aiemmat tutkimukset ole huomioineet kotihoidossa olevien lasten vertailuryhmää. Tämän väitöskirjan tavoitteena oli tutkia varhaislapsuuden stressinsäätelyä sekä kotihoidossa että varhaiskasvatukseen osallistuvilla lapsilla. Lasten kortisolitasoja mitattiin kotona ja päiväkodissa 2- ja 3,5-vuoden iässä. Lisäksi tutkittiin, onko lapsen temperementti yhteydessä lapsen kortisolitasoihin kotona tai päiväkodissa. Lapset valittiin mukaan FinnBrain Syntymäkohorttitutkimuksesta. Tulokset osoittavat, että 2-vuotiaiden lasten keskimääräiset kortisolitasot olivat korkeammat kotihoidossa kuin varhaiskasvatuksessa. Erot kuitenkin tasoittuivat lasten kasvaessa, eikä niitä havaittu enää 3,5-vuoden kohdalla. Varhaiskasvatukseen osallistuvien lasten kohdalla havaittiin lisäksi, että iltapäivän kortisolitasot olivat korkeammat päiväkodissa kuin kotipäivänä vastaavana ajankohtana. Tämä yhteys ilmeni sekä 2-vuotiaana että 3,5-vuoden iässä. Tutkimus osoitti myös, että kaikkein ulospäinsuuntautuneimmilla (ns. surgency/extroversion) lapsilla keskimääräiset kortisolitasot olivat 2-vuotiaana korkeammat sekä kotona että päiväkodissa. Yhteys kuitenkin heikkeni lasten kasvaessa, eikä sitä havaittu enää 3,5-vuoden kohdalla. Tutkimus antaa uutta tietoa lapsen stressinsäätelystä erilaisissa hoitoympäristöissä sekä lapsen iän vaikutuksesta kortisolihormonitasoihin. Tutkimus myös lisää ymmärrystä lapsen temperamenttipiirteiden yhteydestä stressinsäätelyyn sekä siihen liittyvistä herkkyysvaiheista

Children's diurnal cortisol output and temperament in two different childcare settings at 2 and 3.5 years of age

Prior research suggests that child temperament may play an important role in early childhood stress regulation. We compared children's diurnal cortisol and the association between cortisol and temperament in two different childcare settings. Cortisol was measured from saliva samples over 2 days in children (N = 84) attending out-of-home childcare and in children (N = 27), who were cared for at home at the age of 3.5 years. There was no difference between the childcare groups in total diurnal cortisol. However, of the individual measurements, afternoon cortisol levels were higher in the out-of-home childcare group during their childcare day when compared with their home day. Child temperament was not associated with total diurnal cortisol. Comparison with our prior measurements showed that the association between temperamental surgency/extroversion and total diurnal cortisol diminished along with the child age from 2 to 3.5 years in both childcare settings. This may indicate that more extroverted children are physiologically more reactive to environmental stimuli when they are younger, but this association does not appear as the children develop. Our results further suggest that the afternoon hours in the out-of-home childcare may be demanding and accelerate the hypothalamus–pituitary–adrenal axis activation in young children independent of their age.</p

Toddlers’ diurnal cortisol levels affected by out-of-home, center-based childcare and at-home, guardian-supervised childcare: comparison between different caregiving contexts

Previous research suggests that attending non-parental out-of-home childcare is associated with elevated cortisol levels for some children. We aimed to compare diurnal saliva cortisol levels between children having out-of-home, center-based childcare or those having at-home, guardian-supervised childcare in Finland. A total of 213 children, aged 2.1 years (SD = 0.6), were drawn from the ongoing Finnish birth cohort study. Saliva samples were collected over 2 consecutive days (Sunday and Monday), with four samples drawn during each day: 30 min after waking up in the morning, at 10 am, between 2 and 3 pm, and in the evening before sleep. These results suggest that the shapes of the diurnal cortisol profiles were similar in both childcare groups following a typical circadian rhythm. However, the overall cortisol levels were on average 30% higher (95% CI: [9%, 54%], p = .004) with the at-home childcare in comparison with the out-of-home childcare group. Furthermore, a slight increase in the diurnal cortisol pattern was noticed in both groups and in both measurement days during the afternoon. This increase was 27% higher ([2%, 57%], p = .031) in the out-of-home childcare group during the out-of-home childcare day in comparison with the at-home childcare day. The elevated afternoon cortisol levels were partly explained by the afternoon naps, but there were probably other factors as well producing the cortisol rise during the afternoon hours. Further research is needed to define how a child’s individual characteristic as well as their environmental factors associate with cortisol secretion patterns in different caregiving contexts.</p

Child Temperament and Total Diurnal Cortisol in Out-of-Home Center-Based Child Care and in At-Home Parental Care

The association between child temperament characteristics and total diurnal saliva cortisol in 84 children (M = 2.3 years, SD = 0.6) attending out-of-home, center-based child care and 79 children (M = 2.0 years, SD = 0.5) attending at-home parental care was examined. Saliva samples were collected during two consecutive days, that is, Sunday and Monday, with four samples taken per day. While children higher in surgency had higher total diurnal cortisol production, we did not find evidence that temperament moderated the associations between child-care context and total diurnal cortisol. Negative affectivity and effortful control were not related to cortisol output. Our findings suggest that temperamental surgency may be associated with higher total cortisol production in early childhood across child-care settings.</p

Latent profile analysis of diurnal cortisol patterns at the ages of 2, 3.5, and 5 years : Associations with childcare setting, child individual characteristics, and maternal distress

This study performed latent profile analysis from more than 4000 saliva cortisol samples collected from children at the ages of 2 (T1), 3.5 (T2), and 5 years (T3). Three clearly different cortisol profiles were identified. The largest group at every age point was the Low/Regular latent profile, in which the cortisol slopes followed typical diurnal variation. A smaller proportion of the children belonged to the latent profile with relatively Low/Flat slope, and a minority belonged to the High/Fluctuating latent group, where the overall cortisol values and variations between the slopes were clearly higher than in the other groups. Most of the children who belonged to the High/Fluctuating group were cared for at home, they had higher temperamental surgency and their mothers had more depressive symptoms than in the other latent profile groups. However, only moderate intraindividual stability in diurnal cortisol profiles was observed across the follow-up period. On average, half of the children moved between the groups from T1 to T3. Neither child temperament, social competence, nor sex explained the stability or movement between the groups across age. Variations in cortisol profiles may be caused by the child’s age, and diurnal cortisol rhythm becomes more regular along with development. Methodological issues regarding saliva cortisol research in young children are discussed. Also, more longitudinal research is needed to clarify mechanisms between environmental as well as individual factors and possible dysregulation in a child’s HPA axis functioning.peerReviewe

Child Temperament and Total Diurnal Cortisol in Out‐of‐Home Center‐Based Child Care and in At‐Home Parental Care

The association between child temperament characteristics and total diurnal saliva cortisol in 84 children (M = 2.3 years, SD = 0.6) attending out-of-home, center-based child care and 79 children (M = 2.0 years, SD = 0.5) attending at-home parental care was examined. Saliva samples were collected during two consecutive days, that is, Sunday and Monday, with four samples taken per day. While children higher in surgency had higher total diurnal cortisol production, we did not find evidence that temperament moderated the associations between child-care context and total diurnal cortisol. Negative affectivity and effortful control were not related to cortisol output. Our findings suggest that temperamental surgency may be associated with higher total cortisol production in early childhood across child-care settings.</p

Negative associations between maternal prenatal hair cortisol and child socioemotional problems

Maternal prenatal distress can participate in the programming of offspring development, in which exposure to altered maternal long-term cortisol levels as measured by hair cortisol concentrations (HCC) may contribute. Yet, studies investigating whether and how maternal prenatal HCC associates with problems in child socioemotional development are scarce. Furthermore, questions remain regarding the timing and potential sex-specificity of fetal exposure to altered cortisol levels and whether there are interactions with maternal prenatal distress, such as depressive symptoms. The subjects were drawn from those FinnBrain Birth Cohort families that had maternal reports of child socioemotional problems (the Brief Infant-Toddler Social and Emotional Assessment [BITSEA] at 2 years and/or the Strengths and Difficulties Questionnaire [SDQ] at 5 years) as follows: HCC1 population: maternal mid-pregnancy HCC measured at gestational week 24 with 5 cm segments to depict cortisol levels from the previous five months (n = 321); and HCC2 population: end-of-pregnancy HCC measured 1–3 days after childbirth (5 cm segment; n = 121). Stepwise regression models were utilized in the main analyses and a sensitivity analysis was performed to detect potential biases. Negative associations were observed between maternal HCC2 and child BITSEA Total Problems at 2 years but not with SDQ Total difficulties at 5 years, and neither problem score was associated with HCC1. In descriptive analyses, HCC2 was negatively associated with Internalizing problems at 2 years and SDQ Emotional problems at 5 years. A negative association was observed among 5-year-old girls between maternal HCC1 and SDQ Total Difficulties and the subscales of Conduct and Hyperactivity/inattentive problems. When interactions were also considered, inverse associations between HCC2 and BITSEA Internalizing and Dysregulation Problems were observed in subjects with elevated prenatal depressive symptoms. It was somewhat surprising that only negative associations were observed between maternal HCC and child socioemotional problems. However, there are previous observations of elevated end-of-pregnancy cortisol levels associating with better developmental outcomes. The magnitudes of the observed associations were, as expected, mainly modest. Future studies with a focus on the individual changes of maternal cortisol levels throughout pregnancy as well as studies assessing both maternal and child HPA axis functioning together with child socioemotional development are indicated.Peer reviewe