Interfering factors in the sanitary quality of donated human milk

Introduction: human milk (HM) is a balanced, harmonious biofluid with immunoprotective properties that are important for full-term newborns, but essential for premature infants. Objective: To evaluate the effects of the lack of direct contact between home milk donors and the Human Milk Bank (HMB) team, the influence of the bottle volume used for storing raw milk during home collection, and the impact of seasonal variations on the hygiene and sanitary quality of the donated milk. Methods: analysis of data from an HMB from January 1, 2018, to December 31, 2022. Analyses of the association between the evaluated year, season, and quantity and reason for discarding HM. Results: an increase in donated volume was observed, with a 21.2 % rise in 2020 and 7 % in 2021 compared to 2019. In 2020, HM disposal was 31.6 % and in 2021 34.9 %. In 2021, the disposal of bottles was 32.3 %, with a risk of disposal of 4.53 times. In the spring, the risk of disposal was the highest (1.73 times) compared to the other seasons. In autumn, losses were smaller (0.88 risk). Regarding the bottle volume, the greater the bottle volume, the greater the losses. Conclusions: the findings highlight the importance of recommending face-to-face visits by the HMB team to home-based donors to improve adherence to guidelines and address any doubts. Additionally, the use of smaller bottles for storage and intensive monitoring during hot weather and periods of low relative humidity are strongly advised.