Milk composition and volume during the onset of lactation in a diabetic mother.

Milk volume and composition were examined in a diabetic mother on days 3-7 postpartum. By day 5 milk volume produced and concentrations of sodium, potassium, chloride, lactose, protein, calcium, magnesium, and citrate were within limits of a reference population. Fat content of the milk was slightly lower. Free fatty acids were 2% of total lipid on day 3 but increased to 23% on days 4-7, suggesting impaired esterification in the mammary gland. Total milk lipoprotein lipase increased approximately fourfold during days 4-5. Other changes were 1) low cholesterol content, only one-fifth of normal milk; 2) decreased medium-chain fatty acids, suggesting impairment of fatty acid synthesis in the mammary gland; 3) increased oleic acid; and 4) high concentrations of polyunsaturated fatty acids, suggesting increased chain elongation. These results suggest that diabetes produces changes in lipid metabolism in the mammary gland that alter the composition of milk produced by the diabetic mother.