Predictors of high Na/K in milk: breastfeeding experience and technique

Abstract

Predictors of high Na/K in milk: breastfeeding experience and technique Flores-Quijano ME, Rosa María Morales Casanueva E Instituto Nacional de Perinatología This was a cross-sectional study that included 239 breastfeeding women between 2nd and 12th weeks postpartum. Four sets of information were obtained: babies’ anthropometry and age, demographic and breastfeeding practice (questionnaire), breastfeeding technique (breastfeeding observation); women hand-expressed a milk sample from each breast to quantify Na and K content (atomic absorption spectroscopy, Perkin Elmer 3110). Each category was further classified through the K-Means cluster model using Na/K as the independent variable (< 0.59 normal, 0.60 – 0.99 high, 1.0 > very high), to verify the consistency of the model X2 were performed with Na/K as dependent and classification for each cluster as independent variables. Sets 1 and 4 (the way the babies mouth was aligned and open, low lip reverted, and the way the women positioned the baby to the breast and held her breast to offer it to her baby) created clusters that showed predictive value (p<0.0001); mothers of younger smaller babies (X2=11.19 p< 0.024) and used incorrect breastfeeding technique (X2=9.9; p=0.042) had higher Na/K in milk. Set 3 created a cluster with breastfeeding practice variables such as: the women restricted time on each breast, but it did not show consistency (X2=8.35; p=0.079). We propose that high Na/K in milk at this stage of lactation -which suggests presence of inflammatory process in the breast or the premature involution of the mammary tissue - is related with the woman's breastfeeding experience gained through time and the ability of the baby to thoughtfully extract her mother's milk explained by the breastfeeding technique used.