Human Milk banking

Human milk is recognized as the "gold standard" for infant nutrition. While the mother's own milk is the primary choice, Donor Human Milk (DHM) or Banked Milk is considered a superior alternative to formula when the mother's own milk is unavailable or insufficient.

• Definition and Role: Human milk banking involves the recruitment of donors, collection, screening, processing, storage, and distribution of human milk. It is a critical component in the management of high-risk infants.
• Hierarchy of Feeding Choices: For preterm and LBW babies, the order of preference for milk is:
  1. Mother's own preterm milk (superior composition).
  2. Banked human milk.
  3. Standard infant formula (least preferred due to higher risk of complications like NEC).
• Biological Specificity: Banked milk retains many of the bioactive factors, enzymes, and immunological properties of breast milk, although some components may be altered by processing and freezing. For example, frozen banked breast milk may carry a risk of oxidation leading to cholesterol oxides.

Criteria for Donors

While the sources do not explicitly detail the operational screening protocols of a milk bank (e.g., specific serological testing intervals), the criteria for suitable donors can be extrapolated from the contraindications to breastfeeding and the general health requirements for lactating mothers.

Medical and Behavioral Eligibility

A potential donor must generally be a healthy lactating woman with surplus milk. She must not have conditions that are absolute contraindications for breastfeeding:

• Infections:
  • HIV: Mothers with HIV infection are generally excluded in the context of banking (in the US, breastfeeding is contraindicated; in other settings, risks are weighed, but banking requires safety),.
  • HTLV (Human T-lymphotropic virus): Infection is a contraindication.
  • Ebola: Confirmed infection is a contraindication.
  • Active untreated Tuberculosis: Direct feeding is contraindicated until treatment is established (approx. 2 weeks).
  • Brucellosis: Active untreated brucellosis is a contraindication.
• Substance Use:
  • Drugs of Abuse: Mothers using drugs of abuse are not suitable donors.
  • Chemotherapy/Radioactive Isotopes: Mothers taking antimetabolites, chemotherapeutic agents, or radioactive isotopes cannot donate,,.
• Medications:
  • Certain medications like lithium (antipsychotic), ergot preparations, and certain anticancer drugs are contraindicated,.

Compositional Considerations (Term vs. Preterm Donors)

Milk banks classify milk based on the gestational age of the donor's infant because the composition varies significantly:

• Preterm Milk (PTM): Milk from mothers delivering before 37 weeks. It is higher in protein (up to 2.3 g/100 mL initially), sodium, and energy compared to term milk to meet rapid growth needs.
• Term Milk: Milk from mothers delivering at term. It has lower protein (approx. 1.1 g/100 mL) and sodium.
• Drip Breast Milk (DBM): Milk collected from the contralateral breast during feeding. It typically has lower fat and energy content (approx. 45 kcal/100 mL) compared to expressed milk,.

Collection of Human Milk

Proper collection techniques are vital to maintain hygiene and prevent contamination. The primary methods described involve manual expression and the use of breast pumps.

Preparation for Collection

• Hygiene: Thorough hand washing with soap and water is mandatory before handling the breast or collection containers.
• Container: Use a clean, wide-mouthed container (cup or 'katori') that has been washed thoroughly with soap and water,.

Technique of Manual Expression

Manual expression is a key skill for donors. The technique involves,:

1. Position: Sit or stand comfortably, holding the container near the breast.
2. Placement: Place the thumb above the nipple/areola and the first finger below, opposite the thumb (at least 4 cm from the nipple tip). Support the breast with other fingers.
3. Action:
   • Press the thumb and finger slightly inwards towards the chest wall.
   • Press the breast tissue behind the nipple and areola between the finger and thumb (compressing the lactiferous sinuses).
   • Press and release repeatedly. It should not hurt; pain indicates wrong technique.
4. Rotation: Rotate the position of the fingers around the areola to express milk from all segments (quadrants) of the breast.
5. Avoid: Do not squeeze, pull, or rub the nipple skin, as this causes trauma and does not express milk.
6. Duration: Express one breast for 3–5 minutes until flow slows, then switch to the other. Repeat the cycle 5–6 times for a total of 20–30 minutes,.

Collection via Pumps

• Electric breast pumps are generally more efficient than manual pumps.
• Collection kits must be cleaned with hot soapy water, rinsed, and air-dried after every use.
• Milk can be collected in glass or plastic containers.

Timing and Frequency

• To maintain supply and collect sufficient volume, milk should be expressed frequently, at least 8 times in 24 hours.
• Expression can be done to collect "surplus" milk after the donor has fed her own infant, or if the donor is separated from her infant (e.g., working mothers),.

Storage of Human Milk

Proper storage ensures the immunological and nutritional integrity of the milk while preventing bacterial overgrowth.

Storage Containers

• Containers should be washed thoroughly with soap and water.
• Hard plastic or glass containers are suitable.
• The container should be covered with a clean cloth or lid.

Temperature and Duration Guidelines

The duration of safe storage depends on the temperature:

• Room Temperature: Expressed Breast Milk (EBM) can be kept for 4 hours to 8 hours.
  • Note: Sources vary slightly; strict banking usually adheres to the shorter duration (4 hours), while domestic guidelines may allow up to 8 hours depending on ambient temperature.
• Refrigerator (4°C):
  • Safe for 24 hours.
  • Up to 4 days is cited in some protocols.
• Deep Freezer (-20°C):
  • Safe for 3 months.
  • Up to 6–12 months is cited for optimal long-term storage.

Handling and Thawing

• No Boiling: EBM should not be boiled, as high heat destroys protective substances (immunoglobulins, enzymes).
• Thawing/Warming:
  • If milk needs warming, place the container in a bowl of warm water,.
  • Never use a microwave to thaw or warm milk. It heats unevenly (risk of burns) and can destroy bioactive components.
• Mixing: Stored milk often separates (fat rises to the top). Gently shake the container to recombine the fat globules before use.
• Hygiene: Frozen milk should generally be used within 24 hours of thawing.

Processing (Pasteurization)

• While mother's own milk is often used fresh, banked donor milk typically undergoes processing to ensure safety.
• Pasteurization is indicated for banked milk to eliminate potential pathogens.
• However, processing (like freezing and heating) can affect bioactivity. For instance, oxidation in frozen banked milk can lead to the formation of cholesterol oxides.
• Microwaving formulas or milk can convert amino acids from the natural 'trans' form to the neurotoxic 'cis' form, highlighting the need for gentle thermal processing.

Utilization of Banked Milk

Indications

• Preterm/VLBW Infants: The primary beneficiaries. Banked milk reduces the risk of Necrotizing Enterocolitis (NEC) compared to formula,.
• Sick Newborns: Those unable to breastfeed directly.
• Maternal Factors: When the mother is critically ill, deceased, or has a temporary contraindication to breastfeeding.

Nutritional Fortification

• Banked milk, particularly if it is term milk or mature milk, may not meet the extremely high protein and mineral requirements of a VLBW infant.
• Human Milk Fortifiers (HMF) are often added to banked milk (or mother's own milk) for infants <1500g. HMF provides additional protein, calcium, phosphorus, and vitamins to match intrauterine growth rates.

Administration

• Banked milk should be fed using a cup (katori) and spoon or a paladai.
• Feeding bottles should be avoided to prevent nipple confusion and infection.
• For very small or sick infants, gavage (nasogastric) feeding may be necessary.