In reality, there are very few contraindications to breastfeeding. The French High Authority for Health (HAS) lists the following: "Medical reasons that contraindicate breastfeeding are exceptional, both for the mother (HIV infection, except pasteurisation of milk) and for the newborn (congenital metabolic disorder: galactosaemia)."
Even the smoking and breastfeeding, although it is more than strongly recommended not to smoke, even more so during breastfeeding, it is not a firm contraindication as breast milk remains the best option for your baby. There are, however, steps you can take to limit the harmful effects, as it will have an impact on your baby: do not smoke before or during a feed, but rather just after, whilst spacing the next feed by at least 2 hours. Be mindful of passive smoking.
We are in any case surrounded of pollutants, some of which may be found in breast milk. That said, breast milk is not "polluted" and will always be the best option for your baby. Breastfeeding may even be beneficial in protecting your baby from the effects of these pollutants.
Finally, another common myth: becoming pregnant while breastfeeding is not a contraindication, breastfeeding while pregnant is possible. You can absolutely breastfeed during a pregnancy, but you should make sure you are eating well and getting all the essential nutrients for yourself, your baby, and your baby-to-be. Don't hesitate to speak to your healthcare professional about taking a pregnancy food supplement multivitamins to meet your nutritional needs.
I'm unwell — can I still breastfeed?
In many illnesses (flu, covid, etc.), a breastfeeding mother who is unwell may be contagious even before the first symptoms or fever appear. Before symptoms show, contact between mother and baby has continued, meaning the baby has already been exposed to the illness. In this case, stopping breastfeeding is rather contraindicated! Your milk is remarkable — it will pass on substances (antibodies, etc.) to your baby, helping them to fight the illness and stay protected. To find out more, read our article on fever and breastfeeding.
You should however ensure that any medication you are taking is compatible with breastfeeding. The website of the CRAT lists compatible products, allowing you to breastfeed safely and with peace of mind. This site is also useful for checking compatibility anaesthesia and breastfeeding, as not all anaesthetics are compatible. It states that "as a general rule, the duration of action of general anaesthetics is brief. For most of them, there is no measurement of their passage into breast milk."
For example, lidocaine, bupivacaine and fentanyl are commonly used during labour for anaesthesia. More information on epidural and breastfeeding in our dedicated article.