Abstract
Objective This study aimed to assess the possible association of high breast milk sodium levels with postpartum depression and anxiety. Methods A total of 150 mothers and their healthy, exclusively breastfed newborns aged 8 to 15 days were recruited. Mothers were asked to complete scales for evaluation of postnatal depression and anxiety following an interview for consent and sociodemographic data collection. Breast milk samples were obtained to measure sodium and potassium (K) levels. Results Forty-nine mothers had higher than expected breast milk Na concentrations and a high Na/K ratio. These mothers scored significantly higher on the scales of postnatal depression and state anxiety ( P = 0.018 and P = 0.048, respectively). Conclusions This study shows that compared to normal breast milk Na levels and Na/K ratio, high breast milk Na and high Na/K ratio, with possible serious consequences in infants, are associated with maternal depressive and anxious symptoms in the postpartum period.