During pregnancy, you're likely focused on your growing belly and how your unborn baby's size compares to various fruits and vegetables ("He's the size of a kiwi now!"). But there's another big bodily change that's going on: You're dealing with pregnancy boobs.
From feeling like they're going to burst out of your old bras to watching your areolae take up more real estate on your breasts, it's an understatement to say that your set might go through a transformation. So, what's behind all of these dramatic breast changes? You guessed it: "It's all for lactation," Taraneh Shirazian, M.D., an assistant professor of obstetrics and gynecology at NYU Langone Medical Center, tells SELF. Here's what you can expect from your set when you're expecting.
1. Your breasts will likely become more tender.
Long before you ever pee on a stick, swollen, achy breasts are one of the first early signs of pregnancy. And like nearly all pregnancy changes, you can blame it on hormones. "Breast tenderness is related to the increase in hormones and blood flow to the breast tissue," Leah Millheiser, M.D., an ob/gyn and director of the Female Sexual Medicine Program at Stanford Health Care, tells SELF. Specifically, during pregnancy your levels of estrogen and progesterone are on the rise, Dr. Shirazian says. Just like they can cause sore boobs during your period, they can bring the pain during pregnancy, too.
Beyond that, breast pain during pregnancy "happens because there's so much more breast tissue, so it's under more pressure," Dr. Shirazian says. "There's an increase in fat, and glands expand for milk production. The small veins in the breast are also proliferating to accommodate everything else. It's getting crowded."
The good news is that the aches often don't last for long: "This tenderness usually goes away after the first trimester," Dr. Millheiser says.
2. Veins may become more visible.
Blood volume increases around 50 percent during pregnancy, Kate Frometa, a certified nurse midwife at UCSF Medical Center, tells SELF. Veins are especially noticeable if your skin is lighter, causing that lacy bluish pattern to stand out more.
3. They'll go up a cup size—or not.
During pregnancy, rising hormone levels signal the glands in your breasts to grow to prepare for milk production. You're also gaining weight to support your growing pregnancy, and there's that blood-volume boost, too. All these factors can translate into bigger breasts, but not everyone's set responds this way.
"The amount of breast growth varies from woman to woman, so it is difficult to normalize," Dr. Millheiser says. "There are some women who don’t even notice an appreciable change in breast size during their pregnancies." But when she does see patients' breasts grow during pregnancy, it's around one cup size, she says. This can lead to stretch marks, which are totally normal and happen when the skin expands, especially rapidly, according to the Mayo Clinic.
4. Your nipples might get extra sensitive, and that might make it easier to get turned on. Or it could do the opposite.
Hormonal fluctuations and your breast growth can open up a new world of sensations for your breasts, Dr. Shirazian says. Some women come away from this with increased nipple sensitivity, which can lead to heightened sexual arousal, Dr. Millheiser says. Of course, for others, their nipples become a no-touch zone. "The nipple will sometimes be excruciatingly sensitive," Dr. Shirazian says.
5. Your areolae (and nipples) will likely get bigger and darker.
Rising levels of estrogen and progesterone can cause your areolae and nipples to grow, Dr. Shirazian says, adding, "That continues throughout the pregnancy."
If you notice that in addition to getting bigger while pregnant, your areolae and nipples look darker than before—this is especially common if you have a dark complexion to begin with—you're not imagining things. "Darker [areolae and] nipples are most likely related to a temporary increase in melanin caused by the surge in pregnancy hormones," Dr. Millheiser says.
That melanin change in the areola and nipples may serve a purpose, though the scientific jury is still out. "It turns very quickly into a bullseye," Frometa says, calling these areolae and nipple changes "a neon lunch sign."
6. If you didn't before, you may notice small bumps dotting your areolae.
These little bumps are actually small glands called Montgomery glands. If you've suddenly realized you have them during pregnancy, know that they were actually always there, but they become more prominent and noticeable when someone's pregnant, Frometa says. These glands secret oil to keep the areolae and nipples lubricated, kind of like a built-in body lotion.
7. Your breasts may start leaking milk.
And you thought that only happened to breastfeeding women. It can actually happen even while you're still pregnant. Surprise! Women start producing colostrum, sometimes called "liquid gold" since it's chock-full of antibodies, protein, and carbohydrates, late in pregnancy. "Occasionally, a woman may notice a clear, yellow nipple discharge during pregnancy, which can be colostrum," Dr. Millheiser says.
Dr. Shirazian adds, "Some women notice milk production prior to delivery. It's just because those glands are ready and prepared. If you notice it, you should not be alarmed."
If you see bloody nipple discharge, you should tell your doctor. It could be a sign of mammary duct ectasia, when milk ducts widen, their walls thicken, and the ducts get clogged, Dr. Shirazian says. But occasionally, bloody nipple discharge can be a sign of intraductal carcinoma (also called ductal carcinoma in situ), according to the National Cancer Institute. This happens when abnormal cells are detected in the breast ducts, and it's often called the earliest stage of breast cancer, according to the U.S. Department of Health and Human Services's Office on Women's Health.
You should also seek out some medical expertise if you notice any unusual lumps or skin changes, such as discoloration or swollen breasts that have an orange peel-like texture (called peau d'orange—a sign of inflammatory breast cancer), which should get checked out right away, Frometa says. If you experience any physical changes that make you raise your eyebrows—whether you're pregnant or not—bringing them up with a medical professional is always a good idea.
