How Does Breastfeeding Work – Part 1

How Does Breastfeeding Work Breastfeeding is a phenomenal journey unlike any other in your life.  Bonding with your baby and providing the best nutritional and emotional start to life is an amazing gift you can give your precious child.  Understanding the biology and mechanics of breastfeeding is not only fascinating, it can help you successfully breastfeed.  If you’ve ever thought “how does breastfeeding work” during a breastfeeding session, you’ve come to the right place.  We’re breaking it down for you here.

Early Breast Milk Production

Breast milk production starts as a function of the hormones you produce during pregnancy.  Your body begins producing breast milk as early as your second trimester.  While it is unlikely that you would be able to express it, the lactation process starts during pregnancy to ensure you are ready to feed your baby the good stuff when he arrives.  This early milk is called colostrum and that is what your baby will drink for the first few days after birth.  Colostrum develops through a specific cocktail of hormones that you are brewing during pregnancy.  However, progesterone, another hormone you have during pregnancy, prohibits it from being expressed.

Having a baby changes everything, they say. And this is true for the lactation process too.  When you give birth, your progesterone, estrogen and other hormone levels drop and prolactin levels increase which signals your body to release colostrum for your baby to enjoy.  Although it doesn’t seem like much, colostrum is usually a sufficient source of nutrients for most babies.  It is full of fat and protein that babies need to survive their first few days of life.

Cue the Breast Milk

Two to three days after giving birth, you will start to feel your breasts getting full.  This is when your milk “comes in” and mature breast milk production begins.  Again, this is a by-product of hormones.

When your baby latches, she creates a suction on your milk sinuses that causes milk to flow.  This is one reason why proper latch is so important.  Your baby cannot drink milk adequately without a good latch.  Latch may become more essential when your milk supply levels off a few weeks later and milk is not so abundantly available.  Babies without proper latch and a good suck may then struggle to get milk.

If you thought your breasts were getting large during pregnancy, you may be surprised that they can expand even further to accommodate breastfeeding.  Many new moms experience breast discomfort at this stage because their breasts feel very full and are sometimes engorged.  Feeding or pumping often can help relieve the pain and prevent plugged ducts.

Also, as you and your baby get the hang of breastfeeding and work on proper latch, your nipples may feel sore and tender.  Rubbing breast milk on your nipples and letting them air dry is the best way to heal and soothe sore nipples.  As both of you become more familiar with breastfeeding, the pain usually subsides.  If breastfeeding is extremely painful at any time or if sore nipples persist for more than a few weeks, seek help from a lactation consultant.

These two early stages of breastfeeding are hormonally driven.  They occur whether a baby breastfeeds or not.  It’s not until the next stage that breastfeeding takes on its true persona – a process of supply and demand.  We will dive into this aspect of breastfeeding tomorrow.

Did you Know….

  • The areola becomes dark and enlarged during pregnancy and breastfeeding to help your baby find your nipple.
  • There are 15 to 20 holes on the nipple that can express breast milk.
  • The areola is a self-cleaning device!  The bumps you may notice excrete oil that helps cleanse your breast to keep it free of bacteria and anything else that may cause infection.
  • You produce two types of mature milk: foremilk is thinner and higher in calories while hindmilk is thicker and has more fat.

Sources:, LaLecheLeague and Sutter Health