This review describes the population of milk donors recruited to the Hearts Milk Bank between 2020 and 2021. To our knowledge, this is the first review of characteristics regarding milk donors based in the UK. The data will be useful to those working in milk donation and infant feeding support to understand who is more likely to donate and where further information and support might be useful to expand the number of women who might consider milk donation an option.
Donor demographics broadly mirror findings in previous studies with similar donor age (19, 20), relationship status (21) and employment (22). These data broadly reflected the demographics of women who breastfeed in the UK suggesting that it is not a certain demographic subgroup who donates milk. However, fewer donors were not working either due to unemployment or due to maternity leave than previously reported in a French study (21), possibly as a result of the lack of infant age exclusion criteria at Hearts or reduced maternity leave provision in France (16 weeks only). A further US study noted the majority of milk donors had returned to work (23), representing the more limited maternity leave entitlement and social support compared to families in the UK.
A higher than expected proportion of donors were found to have had a preterm infant (34.2%), with more than expected having infants born less than 34 weeks. This finding could be explained through longer durations of stay in hospital, more emphasis on the importance of establishing a maternal milk supply, more staff lactation support and available time on some NICUs compared to transitional care units, and more likelihood that infants would receive DHM themselves in NICUs than late premature infants or those admitted at term. While this finding needs more exploration, anecdotally, donors who consented to their own child receiving DHM often report to the milk bank team that their donation was influenced by positive experiences of expressing, having recognition of the importance of human milk for premature infants or experiencing their own baby receiving DHM.
A recent scoping review found there was limited information available regarding donor ethnicity (24). In this study, data was comprehensively collected from 2021 and was donor ethnicity was found to be representative of the general England and Wales population (25) but with no Black Caribbean donors. Urgent strategies will need to be developed that are fully informed by this community to ensure equity and the removal of any barriers to donation that currently exist.
Understanding donor characteristics is key to ensuring recruitment and retention of donors is optimised (24). Overall, the donor population at Hearts appeared to be inclusive and diverse. In order to safeguard this inclusivity and ensure the UK donor population is representative of each community, it is essential that engagement with donors continues to ensure the process of becoming a donor and the support from Hearts is sufficient (26, 27). Hearts actively seek donor satisfaction feedback to ensure the processes involved in donating milk are concise and straightforward, with recruitment materials translated where appropriate and where there is translation ability in the milk bank team.
The support for donors offered by milk banks must be tailored to meet the individual needs of the donor (28), and this sensitivity is most acutely important for those mothers donating following a bereavement. In the 2-year period reviewed, 32 donors were bereaved. Donating milk following a bereavement can support donors through their grief (29, 30). Not only does becoming a donor serve as a key role to both physical and emotional healing, but milk banks can constitute a key relationship for these grieving parents (31). The key reasons milk donors give generally include altruistic motivations, a desire to help others and not wasting previously expressed milk (23). For bereaved donors however, the focus may shift as the donation may mean more; in addition to a desire to help others, the milk expressed can give meaning to their loss (29), the expression and donation of their milk can serve as a healing ritual (30) and the process can provide an ongoing connection to their baby and their role as a parent (29, 31).
Whilst there is some research that explores what motivates donors, there is a paucity of studies that examine the retention and support of recruited donors. A previous study noted that the sooner a donor registers following giving birth, the more they will donate (20); a slight trend was noted in this instance. In the review, it was noted that 49% of donors who planned to donate more than once, only donated once, and 7.2% of donors signed up but never donated. A systematic review looking at factors influencing donations identified three key categories of barriers to donating (32): individual barriers, including not qualifying for donation, the need to plan to donate, and challenges with pumping; systematic barriers, including a time-consuming process, lack of support and knowledge from healthcare professionals, and long screening tests; and social barriers, including lack of knowledge about milk banking, religious and cultural beliefs, and working life. Supporting the donors to overcome such barriers is likely to improve not only the donations, but also encourage donors to return with subsequent children and to promote the milk bank, supporting recruitment of new donors (26). Whilst this literature examines at the barriers that influence recruitment and donating, there is scant research exploring ongoing donors. In this current dataset, nine donors made more than 10 donations; with some continuing to donate for more than 10 months. Exploring the reasons around what motivates some donors to continue to express and donate, and what hinders others from fulfilling their intentions to donate more than once is essential, as it can give insight to the milk bank to determine strategies in supporting donors.
From its outset, the Hearts Milk Bank waived any cut-off criteria for donor registration according to the age of infant. Data from this study shows that while the average donation from women with infants older than 6 months was lower than that of women with younger infants, the mean volume of DHM that passed microbiological screening was still over 5 litres. This might be expected as mothers with older infants may have returned to work or be feeding their own baby less frequently and thus have a lower milk supply. Milk banks estimate that between two and three infants in neonatal care are fed, on average with a litre of DHM. This indicates that recruiting from the latter population will still mean a significant contribution, and it remains cost-effective to recruit women with older infants. Becoming a milk donor can have significant psychological benefits, particularly after breastfeeding difficulties, palliative care and health conditions affecting both the mother and infant (24, 33). Screening by the milk bank team should identify donors that may struggle to maintain their supply during full term lactation and facilitate a realistic discussion about the time required for donation. Further studies are ongoing to understand how implementing this structured conversation during the recruitment of donors affects duration of donation, donor satisfaction and overall volume donated.
Aside from enhancing the donor experience to improve donations, improving strategies in supporting donors is likely to make milk banking more cost-effective. It costs approximately £100 to recruit a donor (unpublished data, Hearts Milk Bank), including staff time to review the questionnaire, equipment and postage, ongoing support, and costs for serological screening. If DHM is to be made more equitably available, milk banks need to become as cost-effective and efficient as possible, without compromising individualised support for each donor sparing her time and milk to help others.