Human milk banking: Practical concerns for feeding premature infants

Human milk banks make the benefits of immunological and bacteriocidal properties of breast milk available to premature or sick neonates, although difficulties in storing the perishable commodity are not entirely solved. Refrigeration at 4 degrees C seems to be the optimal storage temperature; fluctuations must be minimized. The maximum length of storage time is not well established but is probably 24 hours. Freezing preserves the milk for a longer period with little loss of nutrients or milk antibodies. While up to 60% of viable microbes die at minus 5-10 degrees C, bacterial growth is more rapid during freezing and thawing cycles. Cow's milk can be stored frozen for 3-4 months; these limits are applied to human milk. Disadvantages of freezing are ice and lactose crystallization, which result in decreased pH, increased salt, and protein dehydration. Monitoring of bacteriological contamination is essential; plate counts are reliable but time consuming. Pooling of milk is common, but may be poor practice for premature infants whose nutritional and immunological needs are best satisfied by their own mothers' milk. (cj)