Breast milk is produced naturally by women and provides the basic nutrition for a baby during the first several
months of life. Breast milk has three different and distinct stages: colostrum, transitional milk, and mature
Colostrum is the first stage of breast milk that occurs during pregnancy and lasts for several
days after the birth of the baby. It is either yellowish or creamy in color. It is also much thicker than the milk
that is produced later in breastfeeding. Colostrum is high in protein, fat-soluble vitamins, minerals, and
immunoglobulins. Immunoglobulins are antibodies that pass from the mother to the baby and provide passive immunity
for the baby. Passive immunity protects the baby from a wide variety of bacterial and viral illnesses. Two to four
days after birth, colostrum will be replaced by transitional milk.
Transitional milk occurs after colostrum and lasts for approximately two weeks. The content of
transitional milk includes high levels of fat, lactose, water-soluble vitamins, and contains more calories than
Mature milk is the final milk that is produced. 90% is water, which is necessary to maintain
hydration of the infant. The other 10% is comprised of carbohydrates, proteins, and fats which are necessary for
both growth and energy. There are two types of mature milk: foremilk and hind-milk.
Foremilk: This type of milk is found during the beginning of the feeding and contains
water, vitamins, and protein.
Hind-milk: This type of milk occurs after the initial release of milk and contains
higher levels of fat, and it is necessary for weight gain.
Both foremilk and hind-milk is necessary when breastfeeding to ensure the baby is receiving
adequate nutrition and will grow and develop properly.