What is it?
Thrush is a fungal infection, caused by a bacteria which we all carry, called candida albicans. Usually, our bodies keep the levels of the bacteria in check, but occasionally, when the environment is just right, it can go forth and multiply – and that's when we call it thrush.
In breastfeeding women, thrush can occur because the bacteria thrives in warm, moist and sugary places – such as your baby's mouth, which is being filled several times a day with your nipples and their nutritious milk.
It's most likely to occur in the first two or three months, when your baby's immunity is still underdeveloped.
If you or your baby have had to take a course of antibiotics, this could make thrush more likely, because the medicine has a detrimental effect on our levels of 'good bacteria', which keep candida albicans under control.
The symptoms of thrush might include sore nipples, which are either dark pink or red, and shiny. They might also crack and bleed without easily healing. You might feel a burning sensation in your nipples, or intense itching. There might be white patches, and you might suddenly find it is painful when you feed, not only on the nipple, but within the breast.
Occasionally, you can have thrush with no noticeable symptoms – but if you happen to notice any white curd-like substances in your baby's mouth, then thrush is likely to be present. And if one of you has it, it's quite likely you both do.
What can I do?
If you have been breastfeeding very happily, and then all of a sudden you are showing the symptoms above, go to your GP.
As thrush can easily be passed between mum and baby, you'll probably both have to undergo a short course of anti-fungal treatment to sort the problem out.
If your nipples are just itchy and sore, you'll be given an anti-fungal cream called miconazole, which you should apply to your nipples between feeds.
Clean your breasts with water after feeding, then apply the cream. You won't need to clean the cream off again before giving your next feed, but wash your hands after each application.
If your nipples have become very inflamed, or are cracked and bleeding, you might also be given a steroid cream, which will help them to heal more quickly.
If you can, do continue to breastfeed as normal – however, don't express and freeze any milk for future use until the infection has passed because it could reinfect your baby... and then you.
If thrush is left alone, it can become extremely painful and might prevent you from breastfeeding at all, so if the first course of treatment doesn't work, go back to your doctor.
To prevent the spread of thrush, wash your hands regularly, especially after nappy changes (be aware it might have made its way on to your baby's bottom), use separate towels and sterilise anything else which goes in your baby's mouth, such as bottle teats and dummies.
In most cases, the unpleasant symptoms of thrush should go within a few days, or up to a week, after starting treatment. Occasionally they can last a little longer, but it is vital that you follow the instructions for the treatment of both you and your baby to the letter, so that you get better simultaneously.
What else could it be?
Although cracked and bleeding nipples can be a symptom of thrush, they do not necessarily mean it is definitely present.
Sometimes, sore nipples can be caused simply by your baby failing to latch on properly. Read more about your breasts after pregnancy, including sore nipples, here.