Pregnant With Breast Cancer

Updated 
August 30, 2013

It’s possible to be diagnosed with breast cancer and be pregnant at the same time. One in 3,000 pregnancies occurs in a woman diagnosed with breast cancer.

You might find out you have breast cancer during pregnancy or soon after. Or, perhaps you first learned of your pregnancy while being evaluated or treated for breast cancer.

When you receive a pregnancy-associated breast cancer diagnosisinfo-icon, your shock, worries, questions and fears are likely to be multiplied by health concerns for your fetus or, after delivery, for your infant. Take heart from knowing that studies suggest pregnant women who receive timely therapies, with precautions to protect the fetus:

  • Have similar survival outcomes as non-pregnant women of the same age treated for the same stageinfo-icon breast cancer  
  • Give birth to babies who show no long-term effects from treatment      

Breast Cancer During Pregnancy

Women under 40 represent 5 percent of new breast cancers, yet 7 to 15 percent may be pregnant at diagnosisinfo-icon.

Breast cancer risk increases with age, so those numbers are expected to go up as more women delay pregnancy. Risk rises slightly for those having a first pregnancy after age 30. Improved detection in young women may also lead to increased cases.

At one time, doctors and women thought pregnancy was too dangerous to continue during breast cancer treatment. It was believed a woman had to either terminate the pregnancy to start treatment right away, or delay therapyinfo-icon and risk her own survival until after the baby was born. Births were often medically induced (started early by a doctor) to speed time to treatment, causing complications for premature babies.

Now, research shows good results for women who have surgeryinfo-icon or chemotherapyinfo-icon for breast cancer at appropriate times during pregnancy. Studies show that:

  • Ending a pregnancy by therapeuticinfo-icon abortion (done for medical reasons) does not improve survival in pregnant women diagnosed with breast cancer
  • Breast cancer treatment in pregnant women should follow the same therapy guidelines as for non-pregnant women, with some changes to protect the fetus. These include using older medicines, where we have much more information about their impact during pregnancy
  • Infants exposed to chemotherapy during pregnancy show normal development after birth

Many women now continue pregnancies during breast cancer treatment. For care, see oncologists and obstetricians or maternalinfo-icon-fetal specialists experienced in helping pregnant women with breast cancer.      

Your doctors may discuss terminating your pregnancy as one option, especially if you are diagnosed early in the first trimester (three months) of pregnancy, or have recurrent breast cancer that requires treatments not known to be safe in pregnant women.

  • What you decide to do is a personal choice, dependent upon your situation
  • Talk with an oncologyinfo-icon social workerinfo-icon or counselor and others you may want to consult

Diagnosing Breast Cancer When Pregnant

Pregnancy can complicate breast cancer diagnosisinfo-icon. Breasts tend to be more dense and lumpy during pregnancy, so it may be difficult to feel a tumorinfo-icon until it grows larger, delaying diagnosis. Your dense breasts also make mammographyinfo-icon less reliable. But if you do feel a massinfo-icon, it’s important to get it checked out promptly.

To decide the best treatment, doctors must know the disease stageinfo-icon, lymph nodeinfo-icon involvement and whether hormoneinfo-icon and HER2 (human epidermal growth factor) receptors are present, just as in a non-pregnant premenopausalinfo-icon woman.

Some diagnostic differences when you are pregnant:

  • MRIinfo-icon is preferred over CT scaninfo-icon due to lack of radiationinfo-icon exposure
    • If you need a CT or bone scaninfo-icon, an experienced radiologistinfo-icon can do them with some changes to regular techniques
  • Ultrasound is effective and safe for the breast, axillary (underarm), abdomen and liver
  • Your biopsyinfo-icon sample may show cellinfo-icon changes due to pregnancy
    • Your pathologistinfo-icon must be told your tissueinfo-icon is from a pregnant breast
    • Breast cancers in pregnant women are often hormone receptorinfo-icon-negative. This is likely due to age and tumor types more common in young women

Treatment During Pregnancy

Before treatment begins, your obstetrician or a maternalinfo-icon-fetal expert should examine the fetus.  

Some therapies carry less risk to the fetus than others:

Discuss the timing of surgeryinfo-icon and anesthesiainfo-icon risks for your fetus in advance with your doctors and anesthesiologistinfo-icon.

  • Mastectomyinfo-icon, removal of breast, may be used in all trimesters
    • avoids need for radiationinfo-icon in most cases
    • when needed, should be done using a similar time between diagnosisinfo-icon and surgery as a non-pregnant woman
  • Lumpectomyinfo-icon, removal of part of breast, is used later in pregnancy, so radiation can happen after delivery  
  • Axillary dissection removes lymphinfo-icon nodes to see if they contain cancer. Sentinel lymph node biopsyinfo-icon can be done safely during pregnancy with a radioactiveinfo-icon tracerinfo-icon rather than blue dye.

In the first trimester, chemotherapyinfo-icon carries a high risk of harm to or miscarriage of your fetus. But some chemotherapy medicines can be used in second and third trimesters.

  • In general, the same medicines and dosing can be used as for non-pregnant women.This may include the combination of doxorubicininfo-icon (Adriamycin), cyclophosphamideinfo-icon (Cytoxaninfo-icon) and 5-fluorouracilinfo-icon, and others
  • Methotrexateinfo-icon should not be used in the first trimester because studies show it causes miscarriage  
  • We are learning more about taxanes during pregnancy; studies have shown acceptable outcomes for the fetus. Your doctor may consider using taxanes if delaying your treatment until after delivery would be significantly longer than it would be if you weren’t pregnant, or your doctor feels the wait is too long
  •   A 2012 study of infants exposed to chemotherapy showed no effects on their general health, growth or neurocognitiveinfo-icon abilities

You should not receive chemotherapy in the three to four weeks before delivery. It’s likely you will get regular ultrasounds during chemotherapy to check the growth of the fetus and the conditioninfo-icon of amniotic fluid and placenta.

You cannot receive radiation therapyinfo-icon during pregnancy, unless it’s possible to expose your fetus to less than 5 to 10 rads. Often, this is not possible in breast cancer.

If you need radiation therapy after a lumpectomy, talk with your doctor about whether delaying radiation until after delivery would be too long a delay. In this case, you could consider mastectomy.

Outcomes After Delivery

When precautions are taken, infants born to mothers who received breast cancer treatment during pregnancy have no more problems than other babies. Studies show:

  • Breast cancer cells do not pass to infants
  • No more birth complications for pregnant women than for women without breast cancer
  • Low birth weight is related to premature delivery, not breast cancer treatment
  • No significant physical or developmental problems seen as children grow

If you keep your breast or breasts, it might be possible for you to breastfeed after delivery, with these cautions:

  • Chemotherapyinfo-icon before delivery significantly reduces milk production. Surgeryinfo-icon may change your breast structure
  • If you have had a mastectomyinfo-icon, be reassured that an infant can receive enough nutritioninfo-icon from a single breast
  • Your pediatrician should follow your infant’s weight during breastfeeding

You should not breastfeed if you have chemotherapy or hormonal therapyinfo-icon after delivery. These medicines travel into breast milk. If you are planning surgery after delivery, you will need to stop breastfeeding to reduce breast size and risk of infectioninfo-icon.

Despite often having breast cancer with more challenging biological features, pregnant women who are treated in a timely way, similar to how they would be treated were they not pregnant, experience no significant difference in recurrences, metastases or overall survival.

Getting Support During Pregnancy

If you are pregnant and diagnosed with breast cancer, it may help you to talk with others who are going through a similar experience, or have gone through it.

You also may be interested in:

  • Pregnancy & Cancer Registry, a confidential database which gathers information about women who are or were pregnant during cancer treatment. A related database collects information on pregnant women who have a history of cancer. Enroll confidentially at (877) 635-4499.

This article was supported by Cooperative Agreement Number DP11-1111 from The Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention. 

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