Understanding Human Breast and Milk Production

The human breasts have been designed to take care of the nutritional needs of the growing child through milk production. Milk is produced by glands present in the breasts, and its production and quantity depends upon different factors.

by Brent Phelps

Milk production by the human breast is one of the most amazing gifts which nature gives every mother for her child. Milk is produced by the milk producing areas in the breast, a gland consisting of connective fatty tissues which protect the milk producing cells. These cells are called alveoli where the milk is produced and carried through ducts in the breast to “milk sinuses” where the milk is collected between every feed. These reservoirs or sinuses are located behind the areola, the darker pigmented area around the nipples. The milk production process is driven by the hormonal changes in the mothers body during and after birth. This article discusses the process of milk production in humans in detail 

Hormonal changes

Milk production is initiated in the womans body from the hormones which are released during pregnancy. It never begins as a supply and demand process, as it takes a while for the milk to start getting produced. During pregnancy, a womans body goes through a hormonal change called the “endocrine control system” which initiates the production of colostrum by the breasts from around the fifth month of pregnancy, known as Lactogenesis I. Colostrum continues to be produced in the next months in small amounts, but actually increases in volume 1 to 2 days after giving birth.

Although colostrum is produced by the breasts in the later months of pregnancy, the presence of hormones like progesterone inhibit the secretion of milk from the breasts. Once the child is born, progesterone and estrogen levels drop drastically, and with high prolactin levels, results in the “let-down” of milk from the breasts. This stage is known as Lactogenesis II.

Milk Synthesis after birth

Once the child is born, the supply of milk from the mothers breasts depends on the demand. This is the maintenance stage of milk synthesis, and is also known as Lactogenesis III. The production of milk is not greatly affected by hormonal levels in the body, but it depends on the removal of milk from the breasts. Human breasts will continue to produce milk for as long as you want, as long as milk removal continues. This is the supply and demand relationship of breast milk production.

Milk production in the human breast

There are 2 factors which affect the production of milk by the breasts. First is the presence of FIL (Feedback Inhibitor of Lactation) which is a small whey protein present in human milk. Larger quantities of this protein in the breasts slow down the milk synthesis process. This normally happens when the breasts are already filled with milk. Once you lactate or pump milk out of the breast using Medela Advanced or an Avent Isis pump, the levels of FIL fall in the breast, speeding up the milk synthesis process. This means, that as long as the breast is full, milk synthesis will be slow and vice versa.

The second factor which affects production of milk in the human breasts is the size and storage capacity of the breasts. If a mom’s breasts are small, that means that they have a less storage capacity. Moms with smaller breasts will have to feed their child frequently, so that they can meet the childs need of milk during the day and night. Mothers with an increased storage capacity can wait longer between feedings, and feed more to a baby by storing more milk in her breasts. The production of milk can be same for both breasts; the difference only being in the storage capacity.

How to increase daily milk production

Milk is produced at all times in the breasts of breastfeeding moms; only the speed matters depending on how full your breasts are. If more milk is collected in your breasts between feedings, the milk synthesis process slows down. However, this milk production process can be increased by continuous feedings or pumping of the breasts at regular intervals, without waiting for the breasts to “fill-up”. By emptying their breasts more frequently during the day, mothers can increase their milk supply. Along with regular emptying of the breasts, you have to make sure that the breasts are emptied as thoroughly as possible during each nursing or pumping session. You can ensure this by using several different methods:

§       Massage and compress your breast to allow as much milk to pump or squeeze out as possible

§       Make sure your baby feels satisfied and filled up before leaving your breast

§       Offer both breasts to your child, one after the other. Wait for your baby to finish at the first breast before offering the second breast

§       If you feel that your baby is not sucking out all the milk and your breasts still feel filled after feeding the baby, you can use a pump to empty your breasts. Pumping should ideally be done between nursing sessions, to allow more milk production by your breasts

Knowing how the human breasts produce milk is essential for all breastfeeding mothers to help them understand their body and how it adjusts to meet the needs of the growing child.