This single-center retrospective observational study includes all human milk donors collaborating with the milk bank at České Budějovice Hospital between 2021 and 2025. Using anonymized data extracted from the hospital database, the study will quantify the frequency of donations and the individual and cumulative volume of donated human milk and will assess the impact of key maternal and perinatal factors - including age, BMI, parity, mode of delivery, and timing of donations - on the quantity and quality of donated milk, based on routine biochemical and microbiological parameters.

Donor human milk is a key component of nutritional care for preterm and high-risk neonates when mother's own milk is unavailable or insufficient. A better under-standing of which factors are associated with higher or lower donated volumes, and with favorable biochemical and microbiological milk characteristics, may help optimize several aspects of milk bank practice. This study aims to characterize a five-year experience from a single hospital-based human milk bank in terms of donation pat-terns and donated milk volume. It also aims to evaluate the relationship between key maternal and perinatal characteristics and both the quantity and routinely assessed quality of donated human milk.

Inclusion Criteria:

• Lactating women who donated human milk to the hospital-based human milk bank at České Budějovice Hospital during the period 2021-2025.
• Accepted as donors according to local eligibility criteria for human milk donation.
• At least one recorded donation of human milk with available data on donation date and volume in the milk bank database.
• Availability of basic maternal and perinatal data (e.g., age, BMI, parity, mode of delivery, timing of donation) in the hospital information sys-tem.

Exclusion Criteria:

• Donors with no recorded volume or date of human milk donation in the milk bank database.
• Records with evident data errors or inconsistencies that cannot be reliably corrected (e.g., implausible dates or volumes).

Lactating women who donated human milk to the hospital-based human milk bank at České Budějovice Hospital between 2021 and 2025. All donors met the local eligi-bility criteria for milk donation and collaborated with the milk bank during the de-fined period.

Individual participant data will not be shared due to the sensitive nature of donor information, absence of explicit consent for external data sharing, and restrictions imposed by local regulations and GDPR.