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What You Need to Know About Pregnancy, Breastfeeding, and Breast Cancer

What You Need to Know About Pregnancy, Breastfeeding, and Breast Cancer

What You Need to Know about Pregnancy, Breastfeeding, and Breast Cancer

Breast cancer may not be completely preventable, but there are steps you can take to improve your chances of staying healthy. While gender, age, family history, genetics, and race are non-modifiable risk factors for breast cancer, alcohol consumption, obesity, low vitamin D levels, and smoking are modifiable risks.

Pregnancy and lactation may reduce your breast cancer risk, but it’s important to know that it’s still possible to develop breast cancer when pregnant or breastfeeding. In fact, 
one in 3,000 pregnant women in the United States is diagnosed with breast cancer. Pregnancy and lactation can potentially complicate screening and treatment, but there are still many options available.

How Do Pregnancy and Breastfeeding Change Your Breasts?

pregnancy and breast cancer

Mammogenesis, or breast development, begins while in utero, continues through puberty, and finishes in the final stages of pregnancy. Lactogenesis is the start of lactation; mammary cells begin secreting milk. During pregnancy, breasts undergo many changes in order to make and secrete milk, including developing additional cells to form ductules, lobules, and alveoli, which aid in the production and movement of milk through the breasts to the nipples for consumption. Pregnant women may notice breast changes including increased breast size or weight, increased prominence of veins, increased breast or nipple sensitivity, change in nipple or areola color, and milk secretion.

How Do Pregnancy and Breastfeeding Decrease Your Breast Cancer Risk?

Pregnancy before age 25 and breastfeeding for longer than one year have been linked to a reduced risk of breast cancer. When pregnant and breastfeeding, women often choose healthier habits, like eating nutritiously, not smoking, and limiting alcohol consumption, which could contribute to decreased breast cancer risk. Because of the changes in the breasts and the production of milk during pregnancy and breastfeeding, scientists also believe breast tissue may become less susceptible to carcinogens. In addition, pregnant women typically miss nine menstrual cycles during pregnancy, and many breastfeeding moms have lactational amenorrhea, which means they could go their entire breastfeeding relationship with no sign of a menstrual cycle. These missed cycles decrease the amount of estrogen released in a woman’s body. Estrogen is linked to increased risk of breast cancer along with several other cancers.

What Breast Cancer Screening Options Are Possible While Pregnant or Breastfeeding?

breastfeeding and breast cancer

The hormones and breast changes involved in pregnancy and breastfeeding can make early identification of breast cancer difficult. The increase in blood flow, breast tissue, and number of milk ducts can cause breasts to become tender and dense, making it harder to feel unusual lumps and bumps.

However, it is still important to make sure you are continually monitoring your breasts for any changes in order to detect cancer early, especially if you are considered to be high risk. While breast cancer during pregnancy is relatively rare, early identification and treatment increase chances of survival.

A self-exam will help you become more familiar with your breasts and their normal features. The best time to perform a self-exam is about one week after your period ends when breast tenderness has subsided. Standing in front of a mirror, look at your breasts with both arms down at your sides and while holding them up over your head. Note their size, shape, and color.

Next, using the pads of three or four fingers, make a circular motion as you touch your breast tissue, feeling for any irregularities or changes. You can move in a pattern to be sure to cover the entire breast. Make sure to do this while sitting and standing so that you can examine both the deep tissue and the superficial tissue of your breasts. Note any asymmetry, abnormal colors, or lumps that are new, bigger, or immovable. If you are uncomfortable checking your own breasts or aren’t sure how to do it, ask your doctor to complete an exam for you or show you how to do one.

If you are pregnant or breastfeeding and have noticed changes in your breast tissue, such as dimpling, irregular lumps or bumps, redness, swelling, or anything else you are concerned about, bring it up to your healthcare provider right away. They may want to perform screening to rule out the possibility of breast cancer. If you are pregnant, ultrasounds are considered safe for you and your unborn child. If you are breastfeeding, a few screening options are considered safe, including ultrasounds, mammograms, and MRIs. According to the American Cancer Society, women who are at a high risk of developing breast cancer should start yearly mammogram screenings at age 30, and those with an average risk should begin yearly screenings at 45.

With a new baby or a baby on the way, it’s especially important to attend to your own well-being. Know the risk factors and your own body, and share what you know with your friends and family so they will also take steps to improve their chances of staying healthy.


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