Breast Changes During Pregnancy and Breastfeeding: What Moms Should Know

About the Author: Dr. Heather Richardson, MD, FACS is a leading breast cancer surgeon and has been caring for patients since 2004. She currently practices at Bedford Breast Center in Beverly Hills, where her work centers on nipple-sparing mastectomies and breast-conserving therapy, including lumpectomies and oncoplastic surgery. She co-devised the Goldilocks mastectomy with her plastic surgery colleague, Dr. Grace Ma, and published the definitive paper outlining the technique and its initial clinical application.

Pregnancy and breastfeeding bring significant changes to the breasts. They may become larger, fuller, more tender, or feel different as the body prepares to produce and provide milk. These changes are a normal part of pregnancy and lactation, but that does not mean every breast change should be dismissed as hormonal. Knowing how your breasts normally look and feel can help you recognize when something has changed and when it is worth talking with your healthcare provider.

During Breast Cancer Awareness Month, my team and I at Bedford Breast Center are proud to partner with BIBS to share an important part of breast health for moms: staying familiar with your breasts, speaking up about changes, and knowing that breast imaging can be performed safely when it is needed.

What Changes Are Normal During Pregnancy and Breastfeeding?

Hormonal changes during this period can make breasts larger, heavier, more sensitive, and lumpier or nodular than before pregnancy. All of these changes are normal and common. Your breast density, which refers to the amount of fibroglandular tissue compared with fatty tissue in the breast, may also shift, with some women becoming more dense during pregnancy and breastfeeding.

Breastfeeding can bring additional changes as milk production fluctuates. The breasts may feel full before feeding and softer afterward. It is also common to develop a galactocele while breastfeeding, which is a benign milk-filled cyst that forms when a milk duct becomes blocked.

As so much can change during this time, becoming familiar with how your breasts normally look and feel can help you recognize when something is different. A breast self-exam is one simple way to regularly check in with your breasts and become more comfortable recognizing your own normal.

How to Perform a Breast Self-Exam

A breast self-exam does not need to be complicated. The goal is to become familiar with the normal look and feel of your breasts so that you can recognize a change. We call this "Knowing Your Normal." We recommend performing a breast self-exam at least once a month, ideally a few days after your menstrual cycle when your breasts are no longer swollen or tender.

1. Look for obvious changes

Stand in front of a mirror with your arms at your hips. Look for changes in size, shape, contour, skin texture, or the appearance of the nipples.

Then raise your arms and look again. Pay attention to changes that are new for you, including dimpling, skin thickening, redness, or a nipple that appears newly pulled inward.

2. Use the pads of your fingers.

Using the flat pads of three fingers, gently feel the breast tissue rather than pinching it between your fingers. Lying down spreads the tissue more evenly and may make changes easier to feel, but isn’t required. Use the pads of your three middle fingers on the opposite hand (not the fingertips!) and apply light, medium, and deep pressure. You can move your hands in two ways: up and down and side-to-side like a grid, or in a spiral motion like a target.

3. Cover the entire area.

Be sure to examine the entire breast area, including up to the collarbones, below the bra line, across the center of the chest, and toward the armpits. Pay attention to any new nipple changes or unusual discharge, and gently feel under each arm, where breast tissue and lymph nodes can extend.

If you are breastfeeding, it is normal for your breasts to feel different at different points throughout the day. Becoming familiar with those natural changes can make it easier to recognize something that feels new or unusual for you.

When Should You Have a Breast Change Checked?

If you notice a new or persistent lump, it is important to have it evaluated by a breast specialist rather than assuming it is simply a result of pregnancy or breastfeeding. Breast imaging, including ultrasound, is often the first imaging tool used when evaluating a palpable lump. Ultrasound can help distinguish a simple fluid-filled cyst or galactocele from a solid mass that may require further evaluation.

A breast lump during pregnancy or breastfeeding does not automatically mean cancer. Many breast changes during this time are related to milk production or other benign conditions. What matters is paying attention to what is new or different for you and having persistent or concerning changes evaluated.

Can You Have a Mammogram While Pregnant or Breastfeeding?

According to The American Society of Breast Surgeons, mammography can be safely performed during pregnancy when medically indicated. The radiation dose is very low, and a mammogram can provide important information when evaluating a concerning finding or looking for calcifications that may not be visible on ultrasound.

Mammograms are also safe during breastfeeding and do not require you to interrupt nursing or “pump and dump.” Since lactating breasts can be denser, I recommend that my patient's nurse or pump shortly before their appointment can help empty the breasts and make the images clearer and more comfortable.

Pregnancy and breastfeeding do not mean that you should ignore your regular breast health care. When to begin or continue routine screening depends on your age, personal and family history, breast cancer risk, and previous imaging. If you are due for a screening mammogram or have been advised to undergo more frequent screening because you are at increased risk, talk with your healthcare provider about the appropriate timing.

Give Yourself Permission to Notice the Changes

Your breasts may look and feel different during pregnancy and breastfeeding. Your body is doing something remarkable, and those changes can be a meaningful part of becoming and being a mother.

At the same time, taking care of your breasts during this chapter does not have to mean worrying about every change. It means knowing your normal, paying attention when something feels different, and knowing when to ask for an evaluation. As I always tell my patients, “When in doubt, get it checked out!”