Breast Milk Production

Breast milk production is a fascinating natural phenomenon that involves a range of hormones controlled by the endocrine system, stimulation of the nerve endings attached to your nipples and a supply and demand system. You’ve probably heard the advice to feed your baby often to boost milk supply. That’s because your baby is able to trigger all of the elements required for breast milk production. Here’s how it works:

Preparing for Breastfeeding during Pregnancy

Your breasts are gearing up for breastfeeding even during pregnancy. Many women experience breast tenderness as an early sign of pregnancy. You may also notice your areola darkening (perhaps to become more visible to your newborn’s immature vision) and additional Montgomery glands (small bumps on the areola) forming.

Inside your breast your glandular tissues are growing due to increased estrogen and progesterone, which accounts for breast enlargement during pregnancy, especially in the third trimester. Milk ducts found between fat cells and the glandular tissue also grow in number and size creating a complex web of pathways throughout your breast leading to your nipples. Each milk duct is connected to one of the 15 to 20 lobes in your breasts. The lobes are made of clusters of lobules which are made of clusters of alveoli. The alveoli connect to smaller branches of milk ducts called ductules.

By the middle of your second trimester progesterone levels increase and allow you to begin breast milk production. The alveoli take in proteins, sugars and fats from the blood stream to get the process going. Chances are you won’t need the milk for many months but if your baby is premature, your supply will be ready and waiting.

Ramping Up Breast Milk Production

Breast Milk ProductionWhen your baby arrives your estrogen and progesterone levels drop quickly and the hormone prolactin kicks into full gear. This is the signal for your body to start producing breast milk. At first you will produce colostrum, a sticky yellowish pre-milk substance that is rich in proteins, vitamins and antibodies to help your baby survive her first few days of life. Within a few days your breast milk production will kick into super-drive and you’ll start producing fattier white milk known as transitional milk. Within three weeks of childbirth your breast milk production has transformed into mature milk that can sustain your baby exclusively for six months and beyond.

The Process of Breast Milk Production

Frequent stimulation and emptying of the breasts is the name of the game when it comes to breastfeeding. When your baby stimulates your breast by suckling (or even when you think of your baby, hear your baby’s cry, smell your baby’s scent or look at a picture of your baby), your body releases oxytocin and prolactin that triggers a “let down” so milk flows from the alveoli to the milk ducts. Between your baby’s compressing latch, tugging suckle and your let down reflex, milk transfers from your nipples into your baby’s mouth.

In addition to this constant stimulation, breasts need to be emptied often to continue breast milk production. This is the supply and demand portion of the process. Your body’s response to a full breast of milk is to cut off production. Receptor sites in the walls of the milk-producing cells of the alveoli stretch and prevent prolactin from entering to stimulate more breast milk production. Even a small amount of residual milk in the breast could decrease milk supply. That’s why it’s important to allow your baby to drain your breasts completely during feedings. When the breast is empty, the cells of the alveoli return to their normal shape and breast milk production resumes.

When your milk supply first comes in but has not yet regulated, you may need to pump to empty your breasts. Over a few weeks your milk supply will level off to meet the needs of your baby. And meet the needs it does! Your milk supply will continue to ebb and flow to support your baby’s growth and nutritional needs through growth spurts, periods of brain development, sickness and for emotional support.

How to Boost Milk Supply

The best ways to boost milk supply is by breastfeeding frequently and until your breasts are empty. This ensures the mechanics of breast milk production are always in motion. The more you breastfeed, the more breast milk you’ll produce. If your baby cannot drain your breasts completely or you are away from your baby during a normal feeding time, pump after feedings or at missed feeding times to ensure you continue to stimulate milk production. Supplementing can interfere with breast milk production because your body learns to produce less milk when you feed less often. Also, as a nursing mother, it’s crucial for you to take care of yourself so you have the energy required to produce breast milk. That means eating a wholesome diet, drinking plenty of water, skipping alcohol, limiting caffeine, being cautious of medications you take and getting sleep when you can.

How to Tell if your Baby is Getting Enough Milk

You’ll know that your baby is getting enough milk if she is gaining weight, soiling and wetting diapers and seems satisfied after feedings. Remember, your baby does not need very much colostrum during her first few days of life because her stomach is extremely small and still filled with water from the womb. After a few days when your milk supply comes in her intake will increase significantly. You’ll know your baby is getting milk if you can see and hear her swallow frequently during a feeding.

Sources: BabyCenter, KellyMom, Parents Magazine, LaLecheLeague, Kids Health and Healthy Children


Loving Moments believes moms should have the knowledge, resources and power to make the healthiest choices for their babies, starting with breastfeeding. In celebration of World Breastfeeding Week and National Breastfeeding Month in August, we are sharing Breastfeeding Basics, our educational blog series that we hope will empower you with information, encouragement and inspiration to meet your breastfeeding goals.