Effects of Extended Freezer Storage on the Integrity of Human Milk.

Objective: To examine the integrity (pH, bacterial counts, host defense factors, nutrient contents, and osmolality) of freshly expressed and previously refrigerated human milk subjected to long-term freezer storage.

Study Design: Mothers donated 100 mL of freshly expressed milk. Samples were divided into baseline, storage at -20°C (fresh frozen) for 1, 3, 6, and 9 months, and prior storage at +4°C for 72 hours (refrigerated frozen) before storage at -20°C for 1 to 9 months.