Finding a lump in your breast is always scary, but rest assured it’s more than likely nothing to worry about. Although it is the most common type of cancer found during pregnancy, it's still very rare (especially if you’re under 35), according to the American Cancer Society.[1]

What's more, the many changes that are happening to your breasts while you’re expecting can cause them to feel more lumpy, heavy and firm than you might be used to.

In fact, there are a number of reasons you might discover a breast lump during pregnancy. Breast lumps may turn out to be benign cysts, though if you’re in your second or third trimester, the most likely explanation is actually a clogged milk duct.

Here’s what to do if you discover a breast lump while you're pregnant, plus some of the other breast changes you may experience during the next nine months.

How should you check for a breast lump?

A breast lump is a bump or bulge of swelling tissue. The lump might protrude from your breast, or you might notice it by feeling your breasts.

The American Cancer Society no longer recommends regular breast self-exam for women who have average risk of breast cancer due to the lack of benefit and higher rates of invasive biopsies for benign disease. However, while regular self breast exams are not advised, breast self-awareness and focus on general breast health is a great way to be proactive for your own health.[2]

The idea of breast self-awareness is to be familiar with your breasts, and their normal lumps and bumps, so you can flag anything unusual to your doctor. This can especially be important during pregnancy and postpartum. If you’re closely in tune with what's "normal" for your body, you’ll be better able to detect changes to your breasts. Though remember, the vast majority of “abnormalities” felt in the breast during this period are completely benign — so don’t stress yourself with worry if you find something.

As you assess your breasts regularly, know that cancerous lumps are not usually red or painful when they first appear the way a blocked milk duct is, nor do they clear up with warm water and massage. Changes to watch for, and that warrant reporting, include any type of new lump, skin changes like thickening, dimples, redness, scales or pain in one spot or that worsens.

But because it’s still possible to get breast cancer while you’re pregnant, be sure to talk with your practitioner if you discover anything suspicious in your breast; don’t wait until after you deliver to get it checked out. Breast mass evaluation does not differ between pregnant and non-pregnant woman, and, if required, radiation exposure from a mammogram is within safe parameters for your baby, so can be performed during pregnancy. Yes, it can be trickier to interpret testing of the breasts for cancer because your breast tissue is denser and lumpier, but it is possible — and it is very important — to get an accurate diagnosis.[3]

What happens if you find a lump in your breast during pregnancy?

If your doctor determines that the lump is likely due to a clogged duct, apply a warm compress regularly (or run hot water on it in the shower) and massage the area, which should help unclog the buildup.

If the lump doesn’t clear up or gets worse, check with your doctor to ensure it’s not infected or isn’t something else.

Possible causes for a breast lump found during pregnancy

Breast lumps that appear during pregnancy are most often a clogged milk duct, otherwise known as a galactocele. As early as the second trimester, your breasts are preparing to nurse your baby, and a milk duct can get blocked — and enlarged — in the process. Clogged milk ducts are usually hard, sometimes red, lumps that are tender to the touch and tend to clear up after a few days (they may continue to clog this same way when you’re lactating). 

The good news: These irritating lumps are your body’s way of preparing to nourish your baby — and if you choose to breastfeed, studies have shown it may reduce your risk of breast cancer later in life.[4]

In addition to a clogged duct, there are several other possible causes for a breast lumps. If a lump is not gone within a week of implementing the routine treatments for a clogged duct, reach out to your practitioner.

Other causes of breast masses found during pregnancy can include:

  • Fibroadenoma. These non-proliferative growths contain benign cells that usually shrink on their own, are removed surgically, or drained of fluid with a needle.
  • Simple cyst. These are fluid-filled masses that can be palpated as a normal component of fibrocystic changes or due to other reactive breast changes. 
  • Breast abscess or infection (mastitis). This type of mass causes localized pain and redness of the breast in addition to fever and malaise.
  • Skin changes. There are many dermatologic conditions that are common when expecting that affect the skin of the breast, such as shingleseczema and PUPPS.
  • Breast atypia or cancer. Thankfully, these are very rare.

Fortunately for most women, breast changes in pregnancy and while breastfeeding tend to be benign and nearly all of the breast lump types and changes you may experience aren’t associated with a higher risk of breast cancer later in life.

What happens if you find a lump in your breast during pregnancy?

If your doctor determines that the lump is likely due to a clogged duct, apply a warm compress regularly (or run hot water on it in the shower) and massage the area, which should help unclog the buildup. If the lump doesn’t clear up or gets worse, check with your doctor to ensure it’s not infected.

What other breast changes might you experience during pregnancy?

Along with lumps and plugged milk ducts, you may notice these other breast changes in pregnancy:

  • Pointy nipples. Your nipples may stick out more than before, and this protrusion can make them feel tender and tingly.
  • Fuller breasts. Surging hormones can cause your breasts to grow, swell and feel heavy.
  • Darker areolas. This area around your nipple may enlarge, darken or become spotted. Your areola may also sprout Montgomery’s tubercles, oil glands that supply lubrication.
  • Your veins. A web of blue veins may appear just below breast skin surface. Veiny breasts may be genetic and are more common in breasts with augmentation surgery or that are large.
  • Discharge. Leaky breasts are a normal part of pregnancy. Sometimes the discharge is watery, though it might also be thick, sticky and yellowish late in pregnancy.