Breast milk is the human body’s natural solution to the nutritional needs and sustenance of the newborn baby. There is something mystic and spiritual to the idea of providing nourishment directly from the female body to the mouth of the child without the corruption of synthesized products.

Breast milk itself, however, can be puzzling to the new mother due to its transformative properties. Its inconsistent nature can cause concern for the inexperienced mother, but it is important to remember that breast milk goes through three distinct phases to ensure the baby’s ever-changing needs are met.

The three phases found in breast milk are colostrum, transitional milk, and finally mature milk, and all three provide distinct services to the development of a healthy, happy baby.

Colostrum

As the initial phase of breast milk, colostrum appears in the final stages of pregnancy and is present for the first days of feeding the newborn. Thick and yellowish to cream-colored, some would say having the appearance of half & half mixed with chicken broth, colostrum is a high-protein, vitamin and mineral-rich milk that aids in the development of the infant’s immune system.

This is achieved by the presence of immunoglobins, which are a type of antibodies that act as a protective buffer between viral and bacterial infections and the newborn’s digestive tract before its immune system is more fully developed.

Young mothers quickly find out the nuances of the newborn digestive process, and learn to appreciate this natural enhancement to protection from illness. The colostrum stage lasts less than a week before giving way to the next phase: transitional milk.

Transitional Milk

Transitional milk is the second phase of breast milk. Higher in calories than colostrum, transitional milk lasts for around two weeks after the colostrum phase has ended. Its composition is changed slightly, with a decrease in the presence of immunoglobins.

Transitional milk also contains more fat, lactose, and water-soluble vitamins which act to jump-start the infant’s energy and virility, which the newborn is likely to express with vigorous fits of deafening screaming. The transitional milk is replaced in the final phase by mature milk.

Mature Milk

Breast milk’s final phase, mature milk, is thin and watery when compared to the colostrum and transitional stages. This is because mature milk is 90% water, the high water content serving to keep the infant from becoming dehydrated during their episodes of crying and habitual regurgitation of partially-digested milk.

The other 10% of mature milk contains carbohydrates, proteins and fats, which work to promote growth and provide energy to the infant. Mature milk itself also comes in two stages during each individual feeding.

The first stage is known as foremilk, occurring at the beginning of the feeding and containing more water, vitamins and protein. The watery foremilk is then followed by creamier hind-milk, which contains higher levels of fat to promote weight gain, and lasts to the end of the feeding.

Both stages of mature milk occur to ensure a healthy balance among hydration, energy, and growth and development.