The Who, What, Where, When and Sometimes, Why.

Breast Cancer Treatment During Pregnancy

Read our blogs:

How is breast cancer found in pregnant women?

Most breast cancers in pregnant women are found when a woman notices a lump or change in her breast, or during a clinical breast exam. Pregnant women may get a clinical breast exam as part of their prenatal care.

Women under 40 usually don’t get screening mammography unless they have an increased risk of breast cancer. Screening mammography may be used in pregnant women and women who are breastfeeding [330] However, their mammograms can be hard to read due to changes in the breast tissue during pregnancy and breastfeeding [330]. So, for women over 40 at average risk of breast cancer, screening mammography is usually delayed until after women give birth and finish breastfeeding.

Follow-up tests if a change or lump is found

If a lump or other change is found, a pregnant woman may have a diagnostic mammogram (with digital breast tomosynthesis) and/or a breast ultrasound to check for breast cancer.

Breast MRI is not used during pregnancy [9]. The contrast agent, gadolinium, used in breast MRI may be harmful to a fetus [9].

Stage at diagnosis

Breast cancer can be hard to detect in [227]:

  • Pregnant women
  • Women who have just given birth
  • Women who are breastfeeding

The increased size and change in the texture of the breasts can make small lumps hard to feel.

This can delay diagnosis [227]. So, breast cancers in pregnant women may be diagnosed at a later stage than in non-pregnant women [227].


Although cancer itself doesn’t affect the fetus, some breast cancer treatments can be harmful [10].

Your treatment plan and the timing of your treatments are chosen to treat your cancer as well as protect the fetus.

Surgery and radiation therapy

Breast surgery is safe during pregnancy.

Although the anesthesia used during surgery can cross the placenta to the fetus, it doesn’t appear to cause birth defects or serious pregnancy problems [228].

Breast reconstruction, however, should be delayed until after the baby is born to avoid further anesthesia and the chance for blood loss.

Radiation therapy is needed after a lumpectomy, but radiation can harm the fetus. So, a mastectomy (instead of a lumpectomy) is usually recommended for pregnant women who are in their first trimester and want to continue their pregnancy [10,228].

Some women in their second or third trimester may consider a lumpectomy [10]. In these cases, radiation therapy is delayed until after the baby is born. This delay doesn’t affect chances for survival [10].

Some women in their second or third trimester may have neoadjuvant chemotherapy (chemotherapy before surgery) [10].


Chemotherapy is not given during the first trimester [10,227-229]. The first trimester is when the chances for drug-related birth defects and miscarriage are greatest [227-229].

During the second and third trimesters, some chemotherapy drugs can be used safely [10].

However, chemotherapy should not be given after week 35 of pregnancy or within 3 weeks of the due date (or planned delivery date) [10]. This gives a woman time to recover from chemotherapy before delivery.

Many women diagnosed in their third trimester wait until after giving birth to have chemotherapy.

Other drug therapies

Other drug therapies for breast cancer treatment, including hormone therapy and HER2-targeted therapy, are not used at any point during pregnancy because of risks to the fetus [10,139,157,161].


The chances of survival for pregnant women with breast cancer are similar to the chances of survival for non-pregnant women of the same age and cancer stage [230-231].

Ending a pregnancy doesn’t improve survival [230-231].


Gina Samet, survivor & mother

“I was diagnosed with breast cancer, and I was 6 months pregnant with my first child. There is hope.”


Breastfeeding after a breast cancer diagnosis

If you’ve been diagnosed with breast cancer and wish to breastfeed, talk with your health care provider.

Breastfeeding should be avoided while being treated with radiation therapy, chemotherapy or other breast cancer drug therapies, including hormone therapy and HER2-targeted therapy [10,139,157,161].

Surgery and radiation therapy may make it difficult to nurse from the treated breast.


Social support is important for young women diagnosed with breast cancer. It’s also important for loved ones, especially spouses, partners and children.

Learn more about social support for young women diagnosed with breast cancer.

Learn more about social support for spouses, partners and other family members.

Susan G. Komen® Support Resources

  • Do you need help? We’re here for you. The Komen Patient Care Center is your trusted, go-to source for timely, accurate breast health and breast cancer information, services and resources. Our navigators offer free, personalized support to patients, caregivers and family members, including education, emotional support, financial assistance, help accessing care and more. Get connected to a Komen navigator by contacting the Breast Care Helpline at 1-877-465-6636 or email to get started. All calls are answered Monday through Thursday, 9 a.m to 7 p.m. ET and Friday, 9 a.m. to 6 p.m. ET. Se habla español.
  • The Komen Breast Cancer and Komen Metastatic (Stage IV) Breast Cancer Facebook groups are places where those with breast cancer and their family and friends can talk with others for friendship and support.
  • Our fact sheets, booklets and other education materials offer additional information.

Updated 06/07/24