Breast Milk Composition
The Different Types of Mature Breast Milk
During each breastfeeding session, the baby should receive two types of mature milk. The foremilk (the milk "in front") is produced at the beginning of each feeding. It contains water, vitamins, and protein.
After the foremilk is expressed, the fat-containing hindmilk (which is heavier and slower moving) is pushed out by the "let-down reflex." Both foremilk and hindmilk are necessary when breastfeeding to ensure that the baby is receiving adequate nutrition to grow and develop properly.
The division of the mature breast milk into fore- and hindmilk occurs naturally between feedings as the milk is being made and "sits around" waiting to be expressed. The fat sticks to the sides of the milk-making lobes, while the watery portion of the milk moves easily up the ducts toward the nipple.
This is why it is important to nurse your baby for more than a few minutes on each side. If your baby just "snacks" on each side, he or she will not be receiving the hind milk. When nursing on both sides, it is likely that your baby will get the foremilk and hindmilk on one side, and only the foremilk on the second side, which is fine. As long as she or he receives the hindmilk with each feeding, your baby will continue to grow and his or her nutritional needs will be fulfilled.
The Let-Down Reflex
After the baby begins nursing and takes in the foremilk, the let-down reflex is triggered. This reflex pushes the hindmilk out of the lobes and into the ducts. There it mixes with the remaining foremilk and creates the perfect combination of filling nourishment for your baby. It is exactly what your baby needs for growth, energy, and brain development.