Who are the donors? A characterisation of two years of volunteer milk donors to a community-based UK milk bank

Abstract Introduction: Demand for donor human milk (DHM) is increasing secondary to increased neonatal unit admissions and acceptability. Recruitment and retention of donors is a priority for human milk banks (HMB), but little data is available to optimise donor recruitment, ensuring donors are effectively and compassionately supported, as well as ensuring operational strategies to maximise inclusivity and efficiency. A review was therefore undertaken of all recruited donors to the Hearts Milk Bank, a large, community-based charitable HMB over a 2-year period. Methods: A retrospective data collection was undertaken to review the demographics, characteristics, and donation history of all donors registered to the Hearts Milk Bank in 2020 or 2021, who donated up to 31 st March 2022. Donor variables included age, ethnicity, location, occupation, pumping modalities and reason for donating, alongside infant variables including gestational age, birthweight, age at registration, and admission to a neonatal unit. Descriptive statistics were calculated based on duration of donation, volume and donation numbers, and microbiological fail rates compared between groups using T-tests. Results: A total of 498 donors were recruited over a 2-year period (2020, n=244; 2021, n=254). Of these, 48 donors who had either donated to Hearts before or continued donating after their infant reached another milk bank’s age limit. Most donors lived with a partner (92%) and every ethnicity was represented with the exceptions of Black Caribbean and Mixed White / Black Caribbean. The mean gestational age at birth was 36 weeks, with 40.5% of infants admitted to the neonatal intensive care unit (NICU). The mean age of the infant at registration was 18.8 weeks. Overall, 47% donors made only a single donation and 7.2% of recruited donors never donated. The mean total volume of milk donated was 14.9 litres, with significantly greater volumes donated by those registered before their infant was 6 months of age (26 - 80 weeks; 15.9 L (range vs. 6.44 L). Conclusions: Donors were broadly reflective of previous studies regarding demographics, and representative of Hearts’ local populations. These findings will support future research that can encourage the recruitment, optimal support and retention of milk donors.