Milky Monday: Lactation Basics

Happy Milky Monday everyone! I'm going to do my best to post weekly, so hopefully a catchy name helps.

I've noticed that a lot of people don't understand how lactation actually works, so I wanted to break it down a bit.

Prenatal and Early Postpartum

During pregnancy, hormones cause growth of the milk building systems within the breasts, and newborn milk called colostrum starts being produced about halfway through the pregnancy.

Colostrum is yellowish and clear in color and is thick and sticky, so it comes out in the perfect amount and speed for baby to learn how to eat. Remember, newborns have never felt hunger or needed to eat before being born, so nursing is something you learn together.

About 3-5 days after birth, milk transitions to a larger volume of milk triggered by the separation of the placenta from the uterus (and therefore the change in hormones). This is commonly referred to as your “milk coming in.” I don't really like that terminology because it implies there wasn't any milk before it transitioned.

This transition sometimes happens suddenly, like a faucet turning on. All of a sudden there's a ton of milk! Nursing or pumping every 2 hours, or as often as baby cues, can help prevent engorgement and set you up for long-term milk-making success.

Making Milk

During the first two weeks postpartum is when you can build the amount of milk making structures in the breast by nursing or pumping frequently. The more you remove milk in those first two weeks, the more milk making structures you'll have.

This is the reason you tend to have more milk with each subsequent baby: you are building on the structures that are already there from your previous experience.

Maintaining Lactation

This hormonally driven milk production ends around 12 weeks postpartum, sometimes earlier, sometimes later. This is what is usually referred to as “milk regulation.” This is when production switches to supply and demand, so the more milk you remove, the more you'll make. This means, the less often you remove milk, the less milk you'll make. It sounds simple, but it seems to be misunderstood often.

You don't need to wait for your breasts to “fill up more” before nursing or expressing. Emptier breasts make milk faster than fuller breasts, and full breasts actually signal your body to make less milk. So make sure to remove milk every 2-3 hours, with no more than one 5 hour stretch at night.

Next week, we'll look at the letdown and the foremilk/hindmilk theory.