Being told you have cancer is never easy. If you've just had a baby, it can feel even more intense — both physically and emotionally. Many new parents hope to breastfeed. If you're starting cancer treatment, you might wonder if it's still safe.

Learning how treatment might affect breastfeeding can help you make informed choices. Some treatments mean you need to stop breastfeeding for a while. In other cases, it may still be possible. If you can't breastfeed, support is available to help you manage your milk supply. Safe options, including infant formula or pasteurised donor milk, can still meet your baby's needs.

It's common to feel emotional. With the right support, you can build a strong bond with your baby, no matter how you feed them.

Can cancer treatment affect breastfeeding?

Cancer treatments can affect whether it is safe to breastfeed your baby. Your healthcare team can guide you and answer your questions about your treatment and if it's safe to breastfeed.

Chemotherapy

Many chemotherapy medicines can pass into your breast milk and may harm your baby. It is usually best to avoid breastfeeding during chemotherapy. Ask your doctor if you need to stop breastfeeding.

Radiation therapy

Some people can continue to breastfeed while having radiation therapy, but this may depend on your specific type of treatment. It is best to ask your doctor whether it is safe to continue breastfeeding in your situation.

Other medicines

Targeted therapies are medicines that attack ('target') a specific marker on cancer cells. It is usually recommended to avoid breastfeeding while having targeted therapies.

Surgery

Most general anaesthetic and sedation medicines used in surgery enter breast milk in very low amounts and are considered safe for healthy, full-term babies. You can usually start breastfeeding again once you are awake, feeling well, and able to care for your baby.

Local anaesthetics are also generally safe to use during breastfeeding.

If your baby was born early or has a medical condition, they may be more sensitive to medicines — even those that pass in small amounts into breast milk.

You may also need pain relief medicines after your surgery.

Ask your doctor for advice if you have surgery planned and are currently breastfeeding.

Can I breastfeed safely if I am being treated for breast cancer?

Your ability to breastfeed depends on the type of breast cancer you have and the treatment you are having:

• Breastfeeding is usually not recommended with radiotherapy, chemotherapy or targeted therapies. Speak to your doctor about your specific treatment.
• If you've had minor breast surgery to remove the cancer, you may be able to breastfeed from one or both breasts.
• If you've had a mastectomy (breast removal) or a partial mastectomy, you may be able to breastfeed with the other breast. If you have had both breasts removed, you will not be able to breastfeed.

If your milk supply is low, formula top-ups ('mixed feeding') may help. Your doctor may be able to recommend or prescribe medicines to increase your milk supply.

Once you've finished cancer treatment, breastfeeding is usually safe.

What if I need to stop breastfeeding?

If you're unable to breastfeed safely, you may need to suppress (stop) your milk production. This can be an emotionally and physically uncomfortable experience, but there are ways to manage it. Ask your doctor or lactation consultant if taking a medicine to suppress your milk production is a good option for you.

Tips to suppress your milk supply:

• Wear a firm, supportive bra or top (but make sure it's not too tight).
• Use cold packs or chilled cabbage leaves for relief.
• Avoid pumping or expressing milk — you can hand express a little milk for comfort, if needed.
• Take pain relief medicines, such as paracetamol, if needed.

How can I feed my baby if I am unable to breastfeed?

Breast milk is ideal for babies, but formula or donor milk are also safe and nutritious options.

All infant formulas sold in Australia must follow strict guidelines to ensure they meet babies' nutritional needs. If your baby has specific nutritional needs due to a medical condition, such as prematurity, talk to their paediatrician.

If your baby is born early, they may be able to have donor human milk from a milk bank — available in some neonatal intensive care (NICU) or special care nurseries (SCN).

A milk bank is a service that collects, processes and safely stores breast milk from screened donors. Breast milk is carefully tested and heated (pasteurised) to reduce the risk of passing on any infections. In Australia, donor milk from a milk bank is only available for premature or very sick babies.

It's important to avoid using shared milk from unknown sources, as it may be unsafe for your baby.

I feel disappointed that I am unable to breastfeed my baby

It is common to feel a sense of loss and disappointment if you had planned to breastfeed your baby and aren't able to. These feelings can be hard to manage, especially when you're already dealing with the emotions that come with cancer treatment.
Talking to people you trust can help you work through these emotions.

There are many ways other that you can bond with your baby aside from breastfeeding:

• Respond to their cues for comfort by holding them close.
• Cuddle, sing and talk to your baby.
• Look into their eyes during bottle feeds.

If your feelings don't go away, or they affect your daily life and relationship with your baby, talk to your doctor or a mental health professional. You don't have to cope alone.

Resources and support

There are many organisations you can turn to for more information and support, including the following:

• Perinatal Anxiety & Depression Australia (PANDA) — call 1300 726 306 to speak with a counsellor.
• The Cancer Council also provides free confidential telephone support on 13 11 20.
• NSW Health has an information sheet on pasteurised donor human milk (milk banks).
• The Australian Breastfeeding Association provides further information on breastfeeding, what to do if breastfeeding is not possible, and breastfeeding after breast surgery.
• COPE provides more information on bonding with your baby.

Call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 or video call. Available 7am to midnight (AET), 7 days a week.

Information for Aboriginal and/or Torres Strait Islander peoples

• The Australian Breastfeeding Association provides breastfeeding resources for Aboriginal and/or Torres Strait Islander families.