Associations between bedtime and nighttime parenting and infant cortisol in the first year.

We examined how maternal care within the bedtime and nighttime contexts influences infant cortisol levels and patterning. Eighty-two mothers (M  = 29.4 years) and infants participated in a longitudinal study when infants were 3, 6, and 9 months old. At each time point, bedtime and nighttime parenting were recorded and infant cortisol at bedtime and the following morning was analyzed. Multilevel model analyses showed that infants had lower cortisol levels when mothers were more emotionally available at bedtime, and infants whose mothers responded more often to their non-distressed cues had lower cortisol levels on average. Less co-sleeping and more maternal responses to infant distress were linked to healthier cortisol patterning. By shedding light on parenting qualities and behaviors that influence infant cortisol, these results indicate avenues for intervention and suggest the utility of studying parenting in infant sleep contexts.