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.