How Does Pregnancy Change Your Breasts? 

For many women, breast changes help identify a pregnancy, but how do they continue to change during each trimester? After all, pregnancy changes our bodies in so many ways—including our breasts. 

From the early phases of pregnancy, all the way through breastfeeding after the baby is born, you can expect your breasts to go through just as many changes as you are during this incredible time. Here’s everything you need to know about how (and when) pregnancy changes your breasts. 

The First Trimester: Welcome to Pregnant Boobs

The first trimester of a pregnancy (which takes place in the first 12 weeks) has more than its fair share of physical and emotional transformations. This, of course, includes your introduction to pregnant boobs. Not to mention those oh-so-memorable pregnant nipples.

During the first trimester of pregnancy, most women’s breasts get larger and feel sore and the nipples can feel particularly sensitive,” explains registered nurse and lactation consultant Sarah Tyack, RN, BSW, IBCLC

Tyack says that these breast changes during the first trimester happen for a variety of reasons, one of the main ones being that there’s an increase in both estrogen and progesterone. “These hormones get triggered as soon as your body knows it’s pregnant,” she explains. In fact, some women say they felt the change in their breasts immediately when they first thought they were pregnant. 

During the first trimester changes, Tyack explains that your body “starts making milk sacs to store breastmilk, hence the increase in size.” Most women will increase at least a whole cup size during their pregnancy, so if you don’t see an increase, Tyack says this could be an indicator of low supply and you may want to reach out to a lactation consultant after your baby is born. 

The Second Trimester: Milk Production Begins

During your second trimester (which occurs between weeks 13-26) you’ll experience a growing belly, discomfort in your back and milk production in your boobs, among other things. According to, this is when your estrogen levels continue to rise and your breasts will feel heavier or fuller as milk ducts develop. 

“During the second trimester, you may notice your breasts still increasing in size,” Tyack says, adding, “But they probably won’t be as sore as they were when the estrogen and progesterone surged in the first trimester. Because of all this, it may be time to switch to maternity bras. 

“Most women don’t fit into their pre-pregnancy bras starting at the second trimester and sometimes even in the first trimester, so they purchase a new bra,” Tyack says, adding that it’s good to find a bra that will fit as your breasts continue to grow during pregnancy and after the baby is born. 

You’ll experience some other changes to your nipples during this time, too. “Your areola and nipples start getting darker,” Tyack says, further explaining, “Since newborn babies don’t see color but they can see contrasts, we think this happens to give the baby a target to find the nipple to breastfeed.” 

While you may start leaking colostrum (the milk your baby will eat when they are first born) in your second or third trimester, Tyack says not to be alarmed as not everyone experiences this. 

Breasts During the Third Trimester

While the third trimester (27-40 weeks) marks the final phase of your pregnancy (hooray!) it also marks, arguably, the most physical discomfort. You may experience everything from leg cramps to constipation to heartburn to insomnia. 

Most certainly everyone you know who has been pregnant will give you tips and tricks to help ease the discomfort, including your breasts. Third trimester boobs can lead to heavier or denser breasts, as well as dryness and itchiness. (Your nipples will also become larger and more pronounced.) 

To ease body pain all over, you may consider a heating pad, and your pregnant boobs may be grateful for a super moisturizing body wash

No matter what you’re feeling during the third trimester, or how you’re coping with it, Tyack reminds you: “You can take comfort in knowing “your body is growing a human being and is preparing to make breastmilk.” 

Nipples During Pregnancy

At each stage of your pregnancy, your nipples and areolas will go through a variety of changes. “The nipples can feel sensitive, especially during the first trimester, because of the surge in the estrogen and progesterone hormones,” Tyack says. 

The nipples and areola get darker and can get larger, too. “Infants see contrast and this increased pigmentation is thought to occur because the infant can see the nipples and areola as a target to latch onto and breastfeed,” she explains. 

For all the nipple changes throughout your pregnancy, there are nipple balms and creams that can soothe and protect the sensitive area. 

Postpartum Breasts

You’ve finally had your baby! As if there weren’t enough changes to adapt to, your breasts still aren’t quite done with their journey. “So many miraculous things happen to your breasts after your baby is born,” Tyack assures. 

Because there’s another shift in your hormones once the placenta comes out, you then start producing milk. Tyack says during the first week after giving birth, your breasts may become engorged, which can be uncomfortable. “It’s both your milk coming in and your body’s reaction to the milk coming in,” she explains.

This can often occur when moms aren’t nursing enough, so if you do find your breasts becoming engorged, you may want to, once again, reach out to a lactation consultant. 

Breast Changes While Breastfeeding

After giving birth, you’ll immediately begin to nourish your baby, and as a result, as Tyack puts it simply: “Your breasts will be larger than you’ve ever seen them.” This is because, in short, “You’re feeding a baby and are constantly making milk. It’s your superpower.” 

Your breasts will continue to change throughout the breastfeeding process. Some of the other breast changes during breastfeeding that you may notice include stretch marks, leaking and tingling. 

Some changes may occur after breastfeeding, such as sagging or breasts becoming misshapen. Of course, every woman is different and what you may experience can be completely different from the next breastfeeding mom. 

Embrace the Change

Our bodies go through so much throughout pregnancy, and as we age. When this occurs, our breasts change with us. While they’re not going to always look the same, they are going to continue to be as beautiful and unique as you are. 

It’s important not to feel ashamed of your breasts and the changes they’ve gone through, rather love them for what they are. They are a vital and incredible part of you and they deserve to be just as admired and appreciated as you should be. 

“I believe that women are their most vulnerable when they’re pregnant, giving birth, and in that first postpartum year,” Tyack says, and in that time you can hear or see things that make you feel bad, but remember that every woman is different, including their breasts and nipples. As Tyack puts it, “It’s part of what makes us human.” 

Get our weekly digest for advice on sex, periods, and life in a female body


Continue the conversation

Leave a Reply

Your email address will not be published. Required fields are marked *