Evaluation of macronutrient content of fresh and frozen human milk over 6 months

In this study; we aimed to see the time-dependent changes in the macronutrient content of early frozen breast milk and also to compare it with fresh breast milk in the first 6 months.

We evaluated the milk samples of 43 mothers who delivered at term. Milk samples after the first 15 days following delivery were expressed and collected dividing into seven aliquots to be stored frozen at -20 °C. Every month freshly collected new milk samples were analyzed together with one aliquot of the stored samples, up to 6 months. The energy, protein, lipid, and carbohydrate contents of samples were analyzed by Miris Human Milk Analyzer.

In the first 3 months, fresh milk had higher caloric and lipid content when compared to frozen samples. The protein content of fresh milk decreased after 2 months and became lower than frozen samples. The energy and lipid content of frozen milk decreased over time but protein and carbohydrate contents stayed stable. Carbohydrate content of fresh and frozen samples did not show major changes.

It may be more suitable to consume the frozen milk that was collected in the early weeks of delivery within first 2 months.