What Changes Can Happen to Your Boobs During Pregnancy?

Size isn't the only thing about your breasts that's affected while you're pregnant.

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During pregnancy, a person's body goes through many changes as the baby—or babies—start to grow. You may experience body weight changes; a difference in hair, skin, and nails; or swelling of hands and feet.

According to the American Pregnancy Association, "[t]he breasts are commonly the first changes most pregnant women notice." Here's a look at some of the things that can happen to your breasts during pregnancy.

Ptosis (Sagging)

It has been thought that ptosis, the medical name for breast sagging, was due to breastfeeding. However, an October 2021 study published in the SAS Journal of Surgery stated: "Pregnancies or weight changes, can highly affect breast ptosis because the skin elasticity and ligamentous support becomes attenuated"—which means that ptosis is the result of breast growth during pregnancy.

"When you gain weight during pregnancy, ligaments in your breasts stretch, just as they do in your abdomen," explained Fahimeh Sasan, DO, assistant professor of obstetrics and gynecology at the Icahn School of Medicine at Mount Sinai in New York City. You may not have that much control over the way your chest changes; how well these ligaments rebound can be credited to—or blamed on—your genes. However, limiting the amount of weight you gain and lose may minimize sinkage, and surgery might also be an option.

Stretch Marks

Striae, or stretch marks, are common during pregnancy. In fact, according to the National Library of Medicine (NLM), stretch marks happen in 43% to 88% of pregnant individuals. All the stretching that occurs during pregnancy and breastfeeding causes the collagen and elastin in your skin to expand.

"A lot of this boils down to genetics, so if your mom or your sister didn't get stretch marks, chances are you won't either," Dr. Sasan assured. However, the opposite is also true, and you might be destined to have stretch marks due to heredity.

Slathering on vitamin E oil or cocoa butter should make the skin feel more supple, but that's about it. Applying Bio-Oil to help boost the skin's elasticity in the earlier stages of pregnancy is one way to keep stretch marks at bay, according to the American Pregnancy Association. Other options are to exercise and eat a diet that is collagen-friendly (e.g., eating foods with vitamins E, C, B2, and B3). But at any rate, it's always best to talk to your healthcare provider before applying moisturizers or doing anything else to take care of stretch marks while you're pregnant.

Size—and Symmetry—Changes

According to the American Pregnancy Association, your breasts will grow over the course of your pregnancy—even to the point of needing to go up a cup size or more. However, they may not grow to be similar in size.

For some pregnant individuals, asymmetrical breasts could even out or symmetrical breasts could no longer be the same size. Most of the time, the size discrepancy is so subtle that it's barely noticeable. But if it bothers you, consider switching to padded bras with removable pads so you can use them on one side. Additionally, if you can't make peace with the size mismatch, cosmetic surgery may be an option—either a breast reduction on one side or a small implant on the other.


You might notice that your breasts may be leaking during pregnancy. In most cases, this is your body's response to preparing for the baby's arrival. The American Pregnancy Association stated that your breasts are prepared for milk production by month five or six.

It added that, during that time, "[s]ome women may notice drops of fluid on their nipple. This fluid is colostrum and will be your baby's first food in the first days after delivery." It starts off thick and yellow but then starts to lose color as the body prepares and produces breastmilk.

However, if you note bloody discharge coming from your breasts during pregnancy, seek medical attention as soon as possible to rule out any serious conditions.

What Changes Can Happen to Your Breasts After Pregnancy?

If you're breastfeeding, you've probably noticed that any baby will trigger your let-down reflex—which is when the hormone oxytocin causes your milk to flow, per the NLM. Other offbeat stimuli for leaking breastmilk include newborn baby smell, running water, and sex.

With every pregnancy, breast density tends to go down, explained Karen Soika, MD, a cosmetic surgeon in Greenwich, Connecticut. Ending up with asymmetrical breasts after your kids have nursed is possible too. "The breast the baby prefers naturally stretches out, as can the nipple," Dr. Sasan said—that's why nipples may look bigger or elongated even after you've weaned.

It's important to know that your breasts may or may not return to their pre-pregnancy size and shape. "Some women's stay large, and others shrink," Dr. Soika said. This is due to a mixture of factors, including genetics, whether or not you're still holding on to a few pregnancy pounds, and your age (younger women tend to have denser breasts, which are less affected by weight fluctuations).

Breast changes are to be expected during pregnancy, but if you have any concerns about those changes, reach out to your healthcare provider for advice.

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