Breastfeeding is an amazing, albeit confusing time, especially if it’s your first go-around. It’s beautiful to be able to feed your baby from your body, but it can also make you feel kind of like an exhausted vending machine. With all the things you have to keep track of (diapers, ounces, hours of sleep, loads of laundry) it can be hard to remember to track what’s happening in your own body. You may have noticed or intuited, however, that your milk production is highest in the morning, not the night. Nope, you’re not imagining this sensation; it’s true of most.
Danielle Downs Spradlin, a certified lactation consultant with Oasis Lactation Services, tells Romper that “Milk production follows a daily hormone cycle that is linked to our light-dark cycle. Humans have a normal surge in prolactin, the primary lactation hormone, some time in the 1 a.m. to 3 a.m. window. Because of this, pumping parents usually notice their morning pump output is higher. Conversely, the afternoon pump output is usually lower. That groggy 2 p.m. feeling we often get is part of our hormone cycle too. Lactation hormones dip around that time.” If you’re feeding in the middle of the night, you may notice your output is highest in the middle of the night. A cool fact that Spradlin adds is that if you move time zones, the hormone surge recalibrates to your new location.
Any person who has breastfed will tell you that it takes some serious mental gymnastics to figure out how much milk your baby drinks in a single feeding session; it's nearly impossible to know for sure. You may be concerned that your baby isn’t getting enough food at night, when your output is lower, but this isn't something to lose sleep over (as if you had any to lose).
“Just like we adults don’t eat exactly 550 calories at each meal, babies don’t get exactly 120 ml at each feed,” Spradlin says. “Snack feeding, big meal feeding, cluster feeding, and dream feeding can all be part of your baby’s totally normal feeding pattern.”
A second reason that your milk output may be higher in the morning is simply a matter of storage capacity in the breast. Storage capacity (this sounds like I’m talking about the trunk of a midsize SUV and I apologize, but that’s what the experts call it, so take it up with them) varies widely. As Amy Kiefer, a research scientist whose focus is on distilling complex literature for soon-to-be and new parents, said in a post on Bloomlife: “The range in breast storage capacity from woman to woman is enormous. In one small study of 13 women, the per breast storage capacity ranged from a meager 2.6 ounces to a whopping 20 ounces–an almost a tenfold difference from breast to breast. Even for the same woman, storage capacity often differed from left breast to right breast.” She adds that according to a 2012 study done by Breastfeeding Medicine, for reasons that are not entirely understood, about two-thirds of women have a right breast with a higher storage capacity than their left. It makes sense that if you’re not pumping or feeding overnight, your breasts will fill causing more milk output in the morning.
Spradlin advises that if and when you’re concerned about your milk output not being enough, consider what you produce in a 24 hour period instead of in each session.
“People commonly want to get more milk in a single pumping session. Breasts are glands, not bladders,” she says. “Some of us just have low storage capacity but are able to make plenty of milk if we look at the 24 hour production level.”
It's totally normal if your milk output is higher in the morning and dips in the afternoon. In related news, there's also a difference in the makeup of breast milk produced in the morning and at night, per Sciencealert. Evening milk contains melatonin and "higher levels of certain DNA building blocks," according to the article. Minerals, iron, and certain immune system supports like antibodies and white blood cells are higher in the day milk. Who knew breast milk was so fascinating?