Comparative study on breast milk of mothers delivering preterm and term infants--protein, fat and lactose.

Milk samples were collected from 35 mothers delivering preterm infants and from 35 mothers delivering term infants at 3 time intervals over the first 3 weeks of lactation. The samples were collected by manual expression from both breasts into polyethylene containers and were frozen at -20 degrees C and stored for analysis. The protein content of preterm milks during the first and second weeks is higher than that of term milk (P less than 0.05). The fat and lactose contents during the first week are slightly more in term milk than in preterm milk. During the third week the fat content of preterm milk is higher but its lactose content was lower. All these differences are not significant. These results are discussed.