Studies have found that mothers normally have high sodium concentrations in their colostrum which shows a rapid decrease in the third day postpartum. A drop in breast milk sodium concentration is highly predictive for successful lactation.

In this study, the relationship between mammary gland permeability and the factors related to mothers and their babies were aimed to be investigated.

The case group consisted of 150 consecutive healthy babies at postpartum 8–15 days. Edinburgh Postnatal Depression Scale, State and Trait Anxiety Inventory and Relationship Scale Questionnaire were applied to the mothers. Milk samples from all mothers were collected. Weights of babies at first month were recorded.

In babies with higher Na concentrations and Na/K ratio in their mothers’ milk, were found to gain less weight at the end of first month and also they were the first babies of the families included in the study. Mothers with higher concentrations of Na in their milk thought they were not appropriate to have a child, had poorer relationships with their own mothers, stated that they had no close friendships and had a past history of mental disorders at significance limits. The EPDS and STAI-I scores of mothers with elevated milk Na concentrations found to be higher.

Regarding this study's results, the risk factors causing an increase in the permeability of the mammary glands were determined as thoughts of not being suitable for motherhood, symptoms of postpartum depression and high levels of anxiety for the mothers.