Relationships between the amount of total protein in human milk, the volume of produced milk and perinatal factors

The concentrations of total protein in human milk on the 5th or 6th day after full-term delivery were measured on 184 women, and the amount of protein per 24 hours was calculated by multiplying protein concentration by 24-hour milk production for the same day. Relationships between the amount of protein, milk volumes and perinatal factors were investigated. 1. The mean values (and standard deviations) for total protein concentration and amount per 24 hours, and milk volumes were 1.89 (0.37) g/dl, 6.60 (2.71) g/24h, 353 (144) ml/24h respectively. A significant negative correlation was found between the concentration of protein and milk volumes. The amount of protein per 24 hours showed a considerably high positive correlation with milk volumes rather than with total protein concentration. 2. Among perinatal factors, the age of the mother and whether the delivery was abnormal affected significantly both the amount of protein and milk volumes. The amount of protein and milk volumes of women 30-39 years old, who delivered abnormally were both significantly reduced. The amount of protein for women who had hemoglobin concentrations less than 11.5 g/dl in the latter period of pregnancy was significantly high. However, significant difference disappeared when those women who had both abnormal delivery and birth weight of their baby was more than mean + 1SD] were excluded.