During pregnancy the breast is greatly increased, sometimes it becomes painful and sensitive. This is due to the increase in hormonal activity, which increases the size of glandular lobules where breast milk is produced later. In the first two or three days after giving birth a woman starts to separate colostrum. A few drops of colostrum, the child can suck immediately after birth. These first drops of breast milk have miraculous properties, besides it is a signal the brain to the mother that needed milk production. Hormone Prolactin stimulates milk production in the mammary glands of the mother. Between the needs of the child in the milk and the process of lactation in the mother there is a subtle interaction: the more the child sucks the milk, the greater its arrives.