Association between stress-related substances in saliva and immune substances in breast milk in puerperae.

Objective: We examined the association between biochemical parameters of stress in puerperae and immune substances in breast milk.

Methods: The participants were 22 mothers 2 weeks after delivery, with normal pregnancy/delivery and a normal puerperal course. We measured the levels of secretory immunoglobulin A (SIgA) and cortisol in saliva and the level of SIgA and the leukocyte count in breast milk and investigated their association.

Results: There was a positive correlation between the salivary and breast milk levels of SIgA (r = .536, p < .05). However, there were no correlations among the salivary level of cortisol and the level of SIgA and leukocyte count in breast milk.

Conclusions: The only association found in our study was between the salivary and breast milk SIgA. The lack of association among SIgA and cortisol may be related to a variety of factors such as production site, diurnal rhythms, and the interval between stress stimulation in mothers and the response of the biomarker.