Salivary cortisol response in mother-infant dyads at high psychosocial risk.

OBJECTIVES: The aim of the present study was to investigate the adrenocortical response to diaper change in mother-infant dyads with psychosocial risk factors.
MATERIAL AND METHODS: Twenty-two mother-infant pairs with well-defined psychosocial problems were included. The mother-infant pairs were treated for 6 weeks in a daycare programme to improve attachment. Salivary cortisol was measured before and after a diaper change during the first and last weeks of enrollment in the programme. Mothers' sensitivity towards their infants' signals was measured using a scale from 1 (highly insensitive) to 9 (highly sensitive) according to Ainsworth.
RESULTS: Median salivary cortisol increased in 15 out of 22 infants after the first diaper change. The increase was most pronounced in the group of infants below 3 months of age (n = 15) where median salivary cortisol increased 170% after the first diaper change (P < 0.05) and decreased 19% after the last diaper change (not significant). Out of these 15 infants, 11 showed an increase in salivary cortisol in response to the first diaper change while four out of 15 did so in response to the last diaper change (P < 0.05). The salivary cortisol response did not change over time in infants aged 3 months or above. A mother's sensitivity to her child increased significantly (P < 0.001) from the first to the last week. In mothers, median salivary cortisol decreased 38% after the first diaper change (P < 0.05) and 57% after the last diaper change (P = 0.001). DISCUSSION: A diaper change is normally not perceived as stressful. The stress response caused by a diaper change may illustrate an insufficiency in the mother-infant relationship before treatment. Professional support improved the mothers' sensitivity and stabilized the stress response to diaper change in the youngest infants.