Cancer During Pregnancy

Approved by the Cancer.Net Editorial Board, 08/2020

Cancer during pregnancy is uncommon. Cancer itself rarely affects the growing fetus (unborn baby). When it does happen, cancer during pregnancy can be more complex to diagnose and treat. This is because tests to diagnose cancer and treatments can affect the fetus, so each step in your medical care will be done carefully. It is important to work with a health care team that has experience treating cancer in pregnancy. Learn more about finding an oncologist.

Being diagnosed with cancer or starting cancer treatment during pregnancy can be very stressful and overwhelming. Throughout this experience, it is important to let your health care team know how you are feeling so they can help you find the support you need. This may include an in-person or online support group for other people who have or had cancer during their pregnancy.

What types of cancer occur in pregnancy?

Breast cancer is the most common cancer found during pregnancy. It affects about 1 in 3,000 women who are pregnant. Other cancers that tend to occur during pregnancy are also generally more common in younger people who are not pregnant, including:

How is cancer during pregnancy diagnosed?

It can be more difficult to detect cancer when a person is pregnant. This is because some cancer symptoms, such as bloating, headaches, or rectal bleeding, are also common during pregnancy in general. Breasts typically get larger and change texture during pregnancy and these breast changes may appear normal. This means that cancer-related changes in pregnant women may be noticed later and therefore be diagnosed later than women who are not pregnant.

Pregnancy can also sometimes reveal cancer. For example, a Pap test done as a part of standard pregnancy care can find cervical cancer, or an ultrasound done during pregnancy can find ovarian cancer.

Some of the tests doctors use to find cancer are safe during pregnancy and for the fetus. Others could possibly be harmful. Always talk with your health care team about each recommended test and let the testing staff know you are pregnant. Common tests used in cancer diagnosis include:

X-ray. Research shows that the level of radiation in diagnostic x-rays is too low to harm the fetus. When possible, a shield is used to cover the abdomen during x-rays.

Computed tomography (CT or CAT) scans. CT scans are like x-rays but are much more exact because they use more radiation. They can find cancer or show the spread of cancer. CT scans of the head and chest are usually safe during pregnancy. This is because they do not expose the fetus to direct radiation. When possible, a shield should be used to cover a pregnant woman's abdomen during all CT scans. CT scans of the abdomen or pelvis should only be done if there is no other option. Talk with your health care team about the need for this scan and any risks.

Other tests. Magnetic resonance imaging (MRI), ultrasound, and a biopsy are usually safe during pregnancy.

How is cancer during pregnancy treated?

Planning cancer treatment during pregnancy requires a multidisciplinary team of different types of medical and health care providers working together. This includes cancer doctors called oncologists and high-risk obstetricians. An obstetrician, sometimes called an OB, is a doctor who cares for women during and after pregnancy.

Your cancer doctors and obstetricians will review and compare the best treatment options for you and any possible risks. This will involve looking at a number of factors. The stage of your pregnancy and the type, size, and stage of the cancer are important. Your doctors will also talk with you about your preferences as you make cancer treatment decisions. Throughout treatment, they will closely monitor you to make sure the baby is healthy.

Sometimes doctors may recommend delaying or avoiding certain treatments during pregnancy. For example:

  • During the first 3 months of pregnancy, some cancer treatments are more likely to harm a fetus. So, your doctors may recommend delaying treatment until the second or third trimester.

  • Some treatments can harm the fetus at any time during pregnancy. Doctors try to avoid using these treatments until after the baby is born. For example, radiation therapy is a powerful treatment that uses high-energy x-rays to destroy cancer cells. Depending on the radiation dose and which area of the body needs treatment, there may be risks to the fetus throughout pregnancy.

  • When doctors find cancer later in pregnancy, they may recommend starting treatment after the baby is born.

  • Doctors may recommend waiting to treat some specific types of cancer, such as early-stage cervical cancer, until after the baby is born.

What cancer treatments can I get during pregnancy?

Some cancer treatments are safer to use during pregnancy than others:

Surgery. During surgery, doctors remove the tumor and some of the healthy tissue around it. There is usually little risk to the fetus. In general, it is the safest cancer treatment during all stages of pregnancy.

Cancer medications. Your treatment plan may include the use of medications to destroy cancer cells, such as chemotherapy. Chemotherapy can only be used during certain times in pregnancy:

  • During the first 3 months of pregnancy, chemotherapy carries risk of birth defects or pregnancy loss. This is when the fetus's organs are still growing.

  • During the second and third trimesters, doctors can give several types of chemotherapy with low risk to the fetus. The placenta acts as a wall protecting the baby, so some drugs cannot pass through. Other drugs only pass through in small amounts. Studies suggest that children exposed to chemotherapy during pregnancy do not show more health issues than children who are not. This includes right after birth and during the child's growth and development.

  • Chemotherapy in the later stages of pregnancy may cause side effects like low blood counts. This can increase the risk of infection and indirectly harm the baby during birth or right after birth.

  • Your health care team may consider inducing labor early to protect the baby from your cancer treatment. This is a decision that will be made with you very carefully, with both your health and your baby's health considered.

  • If you receive chemotherapy after the baby is born, you should not breastfeed the baby. Chemotherapy can transfer to the infant through breast milk.

Does pregnancy affect cancer treatment?

Pregnancy itself does not seem to affect how well cancer treatment works. Finding cancer in a later stage or not starting treatment right away can affect the results of the cancer treatment. Talk with your health care team about how different factors may affect your risk from the cancer and how you recover from treatment.

Questions to ask the health care team

If you are pregnant and recently found out that you have cancer, ask your health care team these questions:

  • How much experience do you have treating pregnant women with cancer?

  • How will you work with my obstetrician?

  • Do I need to have any special tests done to learn more about the cancer? Could there be a risk to my baby in having each test?

  • What are my cancer treatment options?

  • Which treatment plan do you think is best? Why?

  • Do I need to start treatment right away, or should I wait?

  • Could a delay in my treatment affect how I recover from this cancer?

  • Is it safe to continue the pregnancy?

  • What are the short- and long-term risks of my treatment to me? To the baby?

  • How will my baby's health be monitored during my cancer treatment?

  • Will my cancer treatment affect how I give birth?

  • Will I be able to breastfeed?

  • Is there a counselor, oncology social worker, or other team member who can help me cope with the emotional side effects of my diagnosis?

  • What other support services and other resources are available to me? To my family?

Related Resources

Having a Baby After Cancer: Pregnancy

What to Do When You Are Diagnosed With Cancer During Pregnancy


Coping with Uncertainty

Finding Hope During Cancer and Pregnancy: "Your Stories" Podcast

More Information

Hope for Two: The Pregnant with Cancer Network

Pregnancy and Cancer Registry

MedlinePlus: Tumors and Pregnancy

National Cancer Institute: Breast Cancer Treatment During Pregnancy