Breast feeding and anaesthesia


If you need either general anaesthesia or sedation while you are breastfeeding I will always give you specific advice at the time but I thought a blog outlining some general principles might be helpful to patients before they come into hospital.


There are two separate issues: first caring for the mother and secondly the safety of feeding the baby. If you have an operation there are a number of reasons you may not be able to continue breastfeeding; perhaps the most obvious is the fact that you may be in hospital and separated from your child. It is very important to express the milk as otherwise your breasts may be painful or you may even develop mastitis.


In terms of your child, we have to ensure that the milk is safe because some drugs can get into the milk and these can adversely affect a small baby. The commonest example is narcotics such as morphine or fentanyl and even small amounts can be dangerous for a child’s breathing. Fentanyl is used during an anaesthetic. In practice, only a small proportion gets into the milk but the doses we use vary significantly between operations and there is always a risk when the mother has received an anaesthetic technique using high-dose fentanyl. Other narcotics that we use only during surgery such as remifentanil have such a short half life that it is safe to breastfeed after regaining consciousness. Narcotics given via an epidural also do not enter the milk


Morphine gets into the milk more readily, although we tend to use lower doses because morphine is commonly used for pain after surgery and therefore given in analgesic is supposed to anaesthetic doses. Nevertheless it is a risk


Codeine is inactive as a painkiller but it is converted in the liver to morphine. Different people convert different amounts to morphine; so-called pharmacogenetics. If the mother and the baby are both high seroconverters the risk to the baby can be significant.


It is therefore sensible advice to advise mothers not to breastfeed whilst they are on these drugs nor for a day or so afterwards. It is also important to remember to express the milk and not allow the milk to remain in the breast so that any milk the baby receives after this period is ‘fresh’ and narcotic free.


Other painkillers including non-steroidals such as ibuprofen and paracetamol appear to be safe. Most other anaesthetics are safe including propofol and muscle relaxants. I would not give ketamine to a woman in this situation and there are usually safe alternatives. There is little evidence about so-called volatile anaesthetics which are the gases you breathe to maintain unconsciousness but equally no evidence of specific risk


To sum up, my general advice to breastfeeding mothers is to express milk in advance and store it in the fridge. This can be done over several days: if you give your child the milk from the fridge and express a fresh supply it is usually possible to build up enough for several days while you are in hospital or taking narcotics. You should then express the milk during and after your operation according to advice and discard it before starting to feed your baby again when it is safe. I appreciate that there is tremendous pressure on mothers to breastfeed and this blog is not the place to debate this butt there is little medical evidence that your baby will come to harm if he or she has to be bottle fed for a short time