Growth in Milk Banks Strengthens Neonatal Nutrition

In 2023, Spain recorded 320,656 births, of which 21,322 were premature, according to the National Statistics Institute. That figure represents 6.6% of all births, meaning that 1 in every 15 newborns is premature and requires specialized care, with nutrition playing a critical role.

Human milk banks (HMBs) have become the cornerstone of neonatal care in Spain. The first facility opened in 2001 in Palma de Mallorca, followed by a second in 2007 at the 12 de Octubre University Hospital in Madrid, Spain.

The network has since expanded to 22 centers across Spain, operating within blood and tissue banks, neonatology departments, and personalized nutrition units.

A 2023 report from the Spanish Association of Human Milk Banks reported record growth in Spain, with several key measures, including the highest number of donors to date. A total of 2657 donors were accepted, the highest number since the establishment of the HMB network.

Catalonia registered 737 donors, followed by Madrid with 335 donors and the Valencian Community in Spain with 224 donors.

In total, 13,745 liters of milk were donated, with 11,781 liters pasteurized and 9949 liters distributed to hospitals, providing nutritional support for 4290 infants in 83 centers in Spain.

The activities of HMBs in Spain have shown continuous and sustained growth since 2009. The number of accepted donors increased from 175 in 2009 to 2657 in 2023, reflecting a progressive increase in public awareness and participation in this type of altruistic donation.

The volume of donated milk has also increased from 1144 liters in 2009 to 13,745 liters in 2023.

The volume of milk distributed grew more than 10-fold over this period, rising from 774 liters in 2009 to 9949 liters, reflecting the expansion of HMBs’ processing and distribution capacity.

Consequently, the number of infant recipients grew from 333 in 2009 to 4290 in 2023. This increase underscores the vital and expanding clinical role of donor human milk, particularly in premature infants and those with specific medical needs.

Clinical Benefits

For premature infants or those with medical conditions, the World Health Organization, United Nations Children’s Fund, Spanish Society of Neonatology, and Spanish Association of Pediatrics recommend donor human milk when the mother’s milk is unavailable. 

Donor human milk provides protection against serious or potentially fatal illnesses and supports healthy growth and development.

“Human milk is now regarded as a true medicine,” said Carmen Pallás-Alonso, MD, PhD, head of Neonatology at Hospital 12 de Octubre University Hospital, and the director of the milk bank. Scientific evidence has shown that it reduces the risk of necrotizing enterocolitis, infection, and digestive disorders. Its benefits extend over the long term, supporting neurodevelopment and lowering cardiovascular risk in adulthood, including its positive effects on blood pressure and lipid profiles.

Donor Selection

Donors are healthy lactating women who breastfeed their own children and altruistically choose to donate excess milk to help sick or premature infants. Selection involves a personal interview to assess health and lifestyle, as well as serologic testing for HIV, syphilis, human T-lymphotropic virus, hepatitis B and C, and Chagas disease.

Although donation can begin at any stage of lactation, it is recommended to wait 3-8 weeks postpartum to ensure that breastfeeding is well-established.

Milk Processing

At HMBs, milk donated by selected mothers is received, processed, analyzed, stored, and distributed to hospitals to feed newborns who cannot receive their mothers’ milk. The collected milk undergoes rigorous safety and quality control.

First, microbiological analysis detects any contamination, followed by macronutrient testing, including energy, fat, protein, and lactose, allowing healthcare professionals to match the nutritional content of milk to the requirements of each infant.

Milk is then pasteurized using the Holder method (62.5 °C for 30 minutes) to eliminate pathogens, before being cooled, frozen, and stored until distribution.

Online Milk Market

Although uncommon in Spain, commercial online markets for human milk exist in countries such as the US and Canada.

The Spanish Association of Pediatrics warns that this practice carries serious health risks because donor screening and processing cannot be verified.

A study published in Pediatrics found that approximately 11% of human milk samples purchased online were contaminated with cow’s milk.

Laboratory analysis indicated that, in most cases, the level of contamination was sufficiently high to suggest deliberate adulteration rather than accidental exposure.

Research and Global Context

Associations such as the Spanish Association of Human Milk Banks, established in 2008 in Palma de Mallorca, Spain, and the European Milk Bank Association (EMBA), founded in Milan, Italy, in 2010, have been key to promoting safe and effective HMB operations through standardized protocols.

These organizations foster international collaboration and help establish standardized protocols to ensure the quality, traceability, and safety of donated milk.

The online market for human donor milk has expanded. This practice presents documented health risks because it operates without standard controls for donor screening, handling milk, or storage. These risks highlight the importance of stringent regulatory standards for milk distribution.

The EMBA’s Consensus Statement outlines over 100 evidence-based recommendations for milk banking, from donor selection to distribution, highlighting the importance of rigorous oversight of donor selection, heat treatment, storage, and distribution.

These protocols not only safeguard vulnerable newborns but also preserve the beneficial properties of breast milk under controlled conditions, reinforcing its role as a therapeutic tool in hospitals.

Breast milk is essential for newborns; however, recent studies have suggested that it may also help detect breast cancer in mothers months before routine diagnosis.

In 2024, the Maimonides Institute of Biomedical Research of Córdoba (IMIBIC) in Córdoba, Spain, launched the Hera Project, led by Juan de la Haba-Rodríguez, MD, a medical oncologist and researcher at IMIBIC and Reina Sofía University Hospital, and Silvia Guil-Luna, PhD, a postdoctoral researcher affiliated with IMIBIC, Reina Sofía Hospital, and the University of Córdoba in Córdoba, Spain.

The study identified postpartum breast cancer cases using biomarkers in breast milk. The results were presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.

Researchers at the Vall d’Hebron Institute of Oncology, part of the Vall d’Hebron Campus in Barcelona, Spain, have found that breast milk from patients diagnosed with breast cancer during pregnancy or postpartum contains circulating tumor DNA (ctDNA). This ctDNA can be detected through liquid biopsy of breast milk and could become a new tool for the early diagnosis of breast cancer in the postpartum period.

The results of this study were published in Cancer Discovery, which reported the first detection of cell-free tumor DNA in breast milk from patients with breast cancer.

Using droplet digital polymerase chain reaction, researchers detected tumor variants in 87% of breast milk samples, whereas 92% of matched blood plasma samples showed no variants.

This indicated that breast milk may be a more effective medium for tumor DNA analysis.

Next-generation sequencing confirmed these results, showing 71.4% sensitivity and 100% specificity. In two cases, tumor DNA was detected in breast milk collected 18 and 6 months before routine clinical diagnosis, highlighting its potential for earlier breast cancer detection.

This story was translated from El Medico Interactivo.