Breast cancer during pregnancy

1. Is it safe to have a mammogram while pregnant?
2. How is breast cancer during pregnancy diagnosed?
3. Can I continue my pregnancy if I have breast cancer?
4. Who will care for me during and after pregnancy?
5. Can breast cancer affect the baby?
6. Is breast cancer during pregnancy more aggressive?
7. Treating breast cancer during pregnancy and after the birth
8. Giving birth if you have breast cancer
9. Breastfeeding if you have breast cancer
10. Speak to other women diagnosed with breast cancer during pregnancy
11. Practical and financial support
12. Fertility and pregnancy after breast cancer

1. Is it safe to have a mammogram while pregnant? 

Mammograms (breast x-rays) are sometimes offered to help diagnose a breast change during pregnancy. If you’re offered a mammogram while pregnant, shielding can be used to protect your baby from the radiation used.  

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2. How is breast cancer during pregnancy diagnosed? 

If you have any of the symptoms of breast cancer, your GP (local doctor) will carry out an examination and decide whether to refer you to a breast clinic for further tests. Having breast cancer during pregnancy or in the first few months after your baby is born is sometimes called pregnancy-related breast cancer or pregnancy-associated breast cancer.

Breast cancer is normally diagnosed at a breast clinic using a method known as ‘triple assessment’.

The first part of this assessment is a breast examination, which will be carried out by a specialist at the clinic.

You’ll usually be offered an ultrasound scan, which uses high-frequency sound waves to produce an image of the breast. This is completely safe and will not affect your baby in any way. You may also be offered a mammogram.

Although ultrasound and mammograms are usually the best way of detecting any early changes within the breast, sometimes an MRI (magnetic resonance imaging) scan is used as well. An MRI uses magnetic fields and radio waves to produce a series of images of the inside of the breast.

The safety of using breast MRI during pregnancy has not been established. However, most small studies looking at MRI during pregnancy show it’s safe, especially after the first three months (the first trimester).

The final part of the triple assessment includes either taking a sample of breast tissue (core biopsy) or breast cells (fine needle aspiration (FNA)). The sample is then sent to a laboratory to be looked at under a microscope. Core biopsies are more commonly used for pregnant women and may be more reliable in making a diagnosis. Both of these tests are safe for you and your baby. Bruising to the breast is common after a biopsy in pregnant women because of the increased blood supply to the breast at this time.

Occasionally it’s not possible to get a diagnosis using a core biopsy. In this case an excision biopsy may be done, which is a procedure to take a larger sample of breast tissue. Your specialist team will advise what would be best for you and your baby.

If you are breastfeeding when you are having these tests you are sometimes advised to stop and you may be given a drug to stop you producing milk.

CT (computerised tomography) scans, also known as CAT scans, and bone scans are usually not recommended during pregnancy due to the risk of radiation to the baby.

Find out more about the tests you may have and what to expect at your appointment. You can also download or order our booklet on Breast cancer during and after pregnancy.

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3. Can I continuing my pregnancy if I have breast cancer? 

Terminating the pregnancy isn’t usually recommended when breast cancer is diagnosed. Most women will continue their pregnancy while having breast cancer treatment. However, some women choose not to. The decision to terminate a pregnancy is a very personal one. It can be made only by you, or you and your partner if you have one, following a discussion with your specialist team and obstetrician.

There’s no evidence to suggest a termination will improve the outcome for women diagnosed with breast cancer during pregnancy. However, a termination may be discussed if chemotherapy is recommended during the first trimester (for example, if the breast cancer is a type that can grow more rapidly or has spread to other parts of the body). Whatever you decide, it’s important to take time to make the right choice for you.

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4. Who will care for me during and after my pregnancy? 

Your specialist team will include cancer specialists and an obstetrician (a pregnancy and childbirth doctor). You should be referred to a breast cancer specialist with expertise in treating women diagnosed during pregnancy. Your maternity care should be provided by an obstetrician and midwife who have experience in caring for women with cancer in pregnancy. You may be advised to have your baby in an alternative hospital to your closest maternity unit so you can have more specialised care.

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5. Can breast cancer affect the baby? 

There’s no evidence that having breast cancer during pregnancy affects your baby’s development in the womb. You cannot pass cancer on to your baby and there’s no evidence that your child will develop cancer in later life as a result of you having breast cancer while pregnant.

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6. Is breast cancer during pregnancy more aggressive? 

There’s no conclusive evidence that breast cancer during pregnancy is more aggressive than breast cancer occurring at other times. However, because it may be difficult detecting a cancer in the breast during pregnancy there can be a delay in diagnosis, meaning the cancer could be found at a later stage.

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7. Treatment during pregnancy and after the birth 

If you’re diagnosed with breast cancer during pregnancy you will usually be able to have effective treatment for your breast cancer and it shouldn’t affect your baby’s development.

Your specialist team will aim will to ensure you get the best treatment for your breast cancer while also considering the effect on your baby.

A pregnancy is measured in ‘trimesters’. Each trimester of pregnancy represents a number of weeks.

  • first trimester – from conception to 12 weeks
  • second trimester – 13–28 weeks
  • third trimester – 28 weeks to delivery

Generally, the treatment you’re offered during pregnancy will depend on how far you are into your pregnancy when your breast cancer is diagnosed, the type and extent of your breast cancer and your individual circumstances. The aim will be to balance giving you the most effective treatment for your breast cancer and keeping your baby safe.

The following treatments may be given depending on your trimester and whether you have had your baby. If you’re near the end of your pregnancy, your specialist team may decide to delay treatment until after the birth. If you’re breastfeeding, you’ll be advised to stop before receiving any treatment.

Surgery

Surgery can safely be done during all trimesters of pregnancy. You may be offered a choice between mastectomy and breast-conserving surgery.

During the first trimester of pregnancy you’re more likely to be offered a mastectomy. This is because not all women who have a mastectomy need radiotherapy whereas radiotherapy is usually needed after breast-conserving surgery. Radiotherapy is generally not recommended at any time during pregnancy because of the risk of radiation to the baby.

If you’re diagnosed in your second trimester and will be having chemotherapy after your surgery, breast-conserving surgery may also be considered an option. This is because radiotherapy will be given after your chemotherapy treatment has finished, and after your baby has been born.

If you are in your third trimester, breast-conserving surgery may be considered an option as radiotherapy can then be given after the baby is born.

Whichever type of surgery you have, it will involve having a general anaesthetic. This is generally considered safe while you are pregnant although there’s a very slight risk of miscarriage in early pregnancy.

Breast reconstruction

Breast reconstruction at the time of surgery (an immediate reconstruction) is not normally offered during pregnancy, due to changes in the breasts and also to avoid a long time under anaesthetic. However, breast reconstruction will generally be offered at a later date (a delayed reconstruction).

Surgery to the lymph nodes

If you have invasive breast cancer, your specialist team will want to check if any of the lymph nodes (glands) under the arm (axilla) contain cancer cells.

To do this, your surgeon is likely to recommend surgery to remove some or all the lymph nodes. This, along with other information about your breast cancer, helps them decide whether or not you will benefit from any additional treatment after surgery.

Chemotherapy

Certain combinations of chemotherapy drugs can be given during pregnancy. However, chemotherapy should be avoided during the first trimester as it may affect the development of an unborn baby or cause miscarriage. The anti-sickness and steroid treatments used to control side effects are considered safe for pregnant women. Generally, chemotherapy during the second and third trimesters is safe. Most women treated during this time go on to have healthy babies, although there’s some evidence to suggest a small increase in the risk of low birth weight and early delivery. The growth and wellbeing of your baby will be monitored by ultrasound. You’ll be advised to stop having chemotherapy three to four weeks before your due date to avoid complications like infection during or after the birth of your baby. Chemotherapy can be continued after your baby is born.

Breastfeeding should be avoided while having chemotherapy as some chemotherapy drugs are passed through the blood stream into the breast milk.

Radiotherapy 

Radiotherapy is not usually recommended at any stage of pregnancy, as even a very low dose may carry a risk to the baby. Your treatment plan during pregnancy may try to avoid radiotherapy or delay it until after the birth (see our information about surgery as a treatment for breast cancer if you’re pregnant).

If there is no other option than to have radiotherapy during pregnancy, there are some changes that can be made to protect the baby.

Hormone (endocrine) therapy 

Hormone therapy will only be prescribed if your breast cancer has receptors within the cell that bind to the hormone oestrogen known as oestrogen receptor positive or ER+ breast cancer. When oestrogen binds to these receptors, it can stimulate the cancer to grow. All breast cancers are tested for oestrogen receptors using tissue from a biopsy or after surgery. Breast cancers diagnosed during pregnancy are less likely to be oestrogen receptor positive compared to non-pregnant women.

The most commonly prescribed hormone therapies for younger women with breast cancer are tamoxifen and goserelin (Zoladex). Some pre-menopausal women will be given aromatase inhibitors (such as anastrozole, exemestane and letrozole) alongside goserelin. Hormone therapies are not given during pregnancy so if the breast cancer is oestrogen sensitive you won’t begin having hormone therapy until after you baby has been born. If you are having hormone therapy you’ll be advised against breastfeeding your baby.

Targeted cancer therapies (also called biological therapies) 

This is a group of drugs that block the growth and spread of cancer. They target and interfere with processes in the cells that help cancer grow.

The most widely used targeted therapy is trastuzumab (Herceptin). Only people whose cancer has high levels of HER2 (called HER2 positive) will benefit from having trastuzumab. HER2 is a protein that makes cancer cells grow.

Targeted therapies are not usually given during pregnancy. Breastfeeding is not recommended while having trastuzumab or for at least seven months after the last dose.

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8. Giving birth if you have breast cancer 

If you have breast cancer, when you have your baby will depend on the treatment you need and your expected due date. Many women diagnosed during pregnancy go on to complete the full term of their pregnancy and don’t experience any problems during childbirth because of their treatment for breast cancer. If your baby is likely to be born early you’ll be offered a course of steroid injections to help with your baby’s development and reduce the chance of the baby developing breathing problems. Where possible your specialist team will try to avoid a caesarean section as there can be complications from it, such as infection, which can be more likely if your immune system has been affected by chemotherapy.

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9. Breastfeeding if you have breast cancer

Many doctors recommend women who are about to be treated for breast cancer should stop (or not start) breastfeeding. There is no evidence that not being able to breastfeed will affect your ability to bond with or care for your baby. Your midwife will be able to support you during this time.

Breastfeeding may be possible for some women after surgery if they don’t need chemotherapy, radiotherapy, hormone treatment or targeted therapy.

If you aren’t having any drug treatments you can breastfeed from the other (non-treated) breast. Although many women are able to produce milk from the treated breast, the amount of milk is often reduced. Breastfeeding from a breast previously exposed to radiotherapy can cause mastitis (infection) and this can be difficult to treat.

If you have questions about breastfeeding, talk to your breast specialist team and other breastfeeding experts such as your midwife.

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10. Speak to other women diagnosed with breast cancer during or after pregnancy 

As breast cancer during pregnancy is not very common, you may feel alone at this time. You might find it helpful to share your feelings with others who have had a similar experience to you. Breast Cancer Care can put you in touch with another woman who was diagnosed with breast cancer during pregnancy through our Someone Like Me service. Call 0345 077 1893 or email someonelikeme@breastcancercare.org.uk to find out more.

Younger Breast Cancer Network

There is a private Facebook group set up by younger women diagnosed with breast cancer called Younger Breast Cancer Network. You can find it on Facebook by searching ‘Younger Breast Cancer Network’. Several members of the group have been diagnosed during pregnancy or soon after given birth.

Mummy’s Star

Mummy’s Star is a charity supporting pregnancy through cancer and beyond. Contact them directly for details of how to join their private online forum.

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11. Practical and financial support

Being pregnant or caring for a new baby while having treatment for breast cancer is both physically and emotionally draining.

Talk to people close to you about how you feel and take up any offers of practical support and help. You can also talk to your specialist team if you are feeling overwhelmed or have any concerns.

If your family is struggling with extra costs, you may be able to get financial support. Macmillan has lots of information on their website, or you can call their Helpline 0808 808 00 00 for advice.

Turn2us is a charity that can help you access any benefits, grants and financial services that are available to you.

Mummy’s Star also have a small grants programme. See their website for more information.

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12. Fertility and pregnancy after breast cancer

Find out more about how breast cancer treatment can affect fertility, options for preserving fertility and planning pregnancy after breast cancer treatment.

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Last reviewed: May 2018
Next planned review begins 2020

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