Breast milk bank: what it is, how it works and who can donate

Breast milk is the ideal food for babies, and both your own and public breast milk banks can be an option to ensure that our babies receive milk of high nutritional quality. In this post, our midwives, experts in breastfeeding, will give you valuable information about breast milk banks, how they work, and the requirements for donating and receiving breast milk.

When do you start a breast milk bank?

It is recommended that you start to build up a supply of expressed breast milk around the third or fourth week after giving birth, once breastfeeding is established and milk production has settled. This will allow you to have a store of extra expressed breast milk for emergency situations or for when the mother cannot be present to feed the baby.

To have a milk bank ready for your return to work, it will be enough to start it between a month and fifteen days before the set date. It is important to bear in mind that if you need to offer your baby expressed breast milk, whether occasionally, in an emergency or more routinely, the type of bottle you use can make the difference in maintaining your breastfeeding.

Avoid using a generic bottle, as it could confuse your baby and put breastfeeding at risk. We recommend a custom-designed Happymami bottle, made to resemble your breast as closely as possible to help prevent nipple confusion and protect your breastfeeding.

How much breast milk do I need for my breast milk bank?

The amount of breast milk you should store depends on your specific needs. If you plan to be away from your baby for a few hours, you should calculate how many feeds they will need in your absence, bearing in mind that each one is usually around 50 to 100 ml.

If you want to create a breast milk bank to have a reserve available in case of emergency, it is recommended that you store between 300 and 500 ml.

When is it best to express milk, before or after a feed?

To create your breast milk bank, you can express milk at any time of the day or night, but it is easier to do it in the morning, when babies are calmer and do not suckle so often. In the afternoon, during the well-known “witching hour”, expressing milk can be complicated.

So choose the time that best suits your needs: it can be in the morning, from a single breast, several times during the day, during a night feed, an hour after your baby has fed, or even before the next feed.

If I express milk to create a breast milk bank, will there be enough for my baby?

Expressing milk for a breast milk bank does not reduce the amount of milk you will have for your baby, because milk production works by adapting to the demand we place on it. When you express milk from your breasts, your body understands that your baby needs more milk and therefore increases production. You can even express milk before your baby feeds if that is more comfortable for you.

Although it is true that breast pumps can have difficulty stimulating the milk ejection reflex, your baby is able to achieve it within minutes. So if you feel that your breasts are full, you can express milk before the feed and then put your baby to the breast. Sometimes they may protest a little at first because they do not find the milk immediately, but it is only a matter of waiting a few minutes until the stimulation sets the whole breast milk production process in motion.

How do you set up a breast milk bank?

It is essential to bear in mind that building up a breast milk bank must be done in a hygienic and safe way, following the appropriate hygiene and storage guidelines to guarantee the safety and quality of the breast milk.

What containers should I use for my milk bank?

For your milk bank, the recommendation is to freeze the milk in small portions to avoid wasting it and to make thawing easier. Because when you offer expressed milk to your baby for the first time, they may only want a small amount. If you freeze large quantities, you will be forced to thaw more than you need.

Remember that once thawed, the milk can be stored for a maximum of 24 hours in the fridge. If your baby only takes part of the thawed milk, you must discard the rest. If the milk has not been consumed and is kept at a temperature below 25°C, you can offer it at the next feed without needing to warm it again.

Building a milk bank takes effort, so maintaining your breastfeeding will be a priority. When offering expressed breast milk, avoid a generic bottle. The best option is a custom-designed Happymami bottle, made to resemble your anatomy as closely as possible and help prevent nipple confusion.

How long does milk last in the milk bank?

To maximise the nutritional and health benefits of breast milk, it is recommended to use fresh refrigerated breast milk whenever possible, as this preserves the living cellular components and other beneficial nutrients found in breast milk. Fresh refrigerated breast milk is also ideal for everyday use, as its composition changes throughout the different stages of your baby's development and provides the specific nutrients your baby needs at that moment.

Breast milk in your milk bank can last in the fridge for between 3 and 8 days if stored in the coldest part of the fridge, with 5 days being the optimum time. It is advisable to freeze the milk after the first 24 hours for better preservation. Once you have collected the optimal 50-75 ml for freezing, it is safe to do so.

Breast milk can be kept frozen at -20°C for around 6 months, but bear in mind that it can become “freezer burnt”, which can be seen in the formation of small streaks in the milk and the appearance of ice inside the container. To prevent the milk from spoiling, it is important to always mark the containers with the date of expression and to use the oldest milk when needed.

What are donated breast milk banks?

Breast milk banks are specialised centres responsible for collecting, processing and distributing breast milk donated by breastfeeding mothers to babies who need it, under medical supervision. These breast milk banks are responsible for carrying out a rigorous selection and analysis of the donated milk to ensure its quality and safety for consumption, so that it can be offered to premature babies, babies with low birth weight, or babies with illnesses or allergies that prevent them from taking their own mother's milk.

In addition, milk banks also offer information and support to breastfeeding mothers to encourage breastfeeding and help resolve any problems they may have during the breastfeeding process.

Who can donate to a breast milk bank?

Donors for breast milk banks are healthy women with a healthy lifestyle who breastfeed their child successfully and who decide to donate milk altruistically for the benefit of sick or premature newborns. Donors are selected through a personal interview in which data is collected on their state of health and lifestyle habits.

In addition, donors undergo a serological study to rule out diseases that can potentially be transmitted through milk, such as HTLV, syphilis, HIV, hepatitis B and C, and Chagas. Donation can begin at any time during breastfeeding, but it is recommended to wait between 3 and 8 weeks after giving birth so that breastfeeding of your own child is properly established.

Can I be a breast milk donor for a milk bank?

Any healthy mother who is successfully breastfeeding her child and who wants to express milk to donate it can do so. However, there are some situations in which it is not possible to donate milk. If you consume alcohol, tobacco, drugs or excess caffeine, or if you suffer from a significant chronic illness or regularly take a medicine that is incompatible with breastfeeding, then you cannot be a donor.

Furthermore, if you suffer from an infectious disease such as hepatitis B or C, HIV or syphilis, or if you belong to a risk group for contracting these infections, you cannot donate milk either. Before starting the donation, mothers are tested to rule out the presence of these infections.

In some special situations, it is also possible to donate milk to the bank. For example, if you accumulated a large volume of milk during a child's hospital stay, or if you wish to donate after the death of a child and the appropriate conditions for expression and storage have been followed, you can do so too. Every donation is very valuable and can help premature and sick babies receive the nutrition they need!

How much do they pay for donating to a breast milk bank?

Donating breast milk is an altruistic act and no payment is received for it. Breast milk banks work with voluntary donors who want to help other babies who need breast milk. In some cases, breast milk banks can provide donors with materials such as breast milk storage bags or breast pumps, but they are not paid for their milk.

How is donated milk managed in the milk bank?

Human milk banks are responsible for collecting the donated milk and subjecting it to microbiological analysis to guarantee its safety. Macronutrient analyses are also carried out to determine the energy, fat, protein and lactose content of the milk that will be dispensed. Processing includes heat treatments to eliminate contaminating bacteria and ensure the absence of viruses.

The Holder pasteurisation method is the most widely used by the majority of breast milk banks, and after this process the milk is frozen and stored until distribution. It should be noted that donated milk is neither bought nor sold, as it is a voluntary and altruistic donation from healthy breastfeeding women who are committed to the health of the babies who need it most.

How is breast milk donated to a milk bank?

If you are interested in donating breast milk to a milk bank, you can contact the neonatal units of the milk bank by phone, email or in person to arrange an appointment.

During the visit, you will be provided with detailed information about the donation process and, if you wish to continue, a clinical interview will be carried out and you will be asked for your written informed consent. A blood sample will also be taken to rule out the infections mentioned above.

Once we receive the analytical results, we will inform you whether they are satisfactory for continuing with the donation. At that point, you will be provided with information about expressing and storing the milk, as well as the material needed to collect it.

It is important to remember that donating breast milk is a voluntary act and that any healthy mother who meets the criteria can be a donor. In addition, donated milk is subjected to rigorous microbiological and nutrient analyses to guarantee its safety and quality before being processed and distributed to the newborns who need it.

Who can receive donated milk from a breast milk bank?

Donated milk is intended to be used by hospitalised patients who need to be fed with breast milk and cannot be breastfed by their own mother. Among them are premature newborns weighing less than 1,500 grams at birth or with a gestational age of less than 32 weeks. Other patients who require special care can also benefit from donated milk, such as newborns who need intestinal surgery, have congenital heart disease, severe growth delays, or who have other conditions that require specific nutrition.

Is it possible to know the recipient of my milk donated to the breast milk bank?

It is not possible to know the recipient of your donated milk, as the donation is anonymous for both the donor and the recipient.

Conclusion on breast milk banks

In conclusion, breast milk is the ideal food for babies and building up an extra supply is a good option to have in case of emergencies or for when the mother cannot be present to feed the baby.

Milk banks, whether your own or public, can be an option to ensure that babies receive milk of high nutritional quality. It is important to follow the appropriate hygiene and storage guidelines to guarantee the safety and quality of the breast milk.

In general, breast milk banks are a good option to help ensure that babies receive adequate nutrition, as long as the appropriate hygiene and storage protocols are followed.

Bibliography on breast milk banks

1. Fabm, A. K. M. I. (2022, 13 July). Breastfeeding: Parental education and support. Uptodate.com.
2. Spanish Association of Paediatrics, Breastfeeding Committee. (2018). DO YOU KNOW ABOUT MILK BANKS? Aeped.es. Link
3. Compartir, L. (no date). SHARING BREAST MILK. Aeped.es. Retrieved on 20 February 2023, Link.
4. Banc de Llet Materna – Centre de transfusió . Gva.es. . Available at: centro-transfusion.san.gva.es
5. Padró A. How to set up a milk bank at home – The most complete and personalised breastfeeding app . The most complete and personalised breastfeeding app | LactApp. 2018 . Available at: blog.lactapp.es