Thrush and newborns
If you notice white patches in your baby's mouth that won't rub off, your baby most likely has thrush - a harmless yeast infection of the mouth. All babies come into contact with yeast and maintain it with "good bacteria" but a recent dose of antibiotics (in either you or your baby) could kill too much of the bacteria to maintain a healthy balance. If an overgrowth occurs, yeast will grow in moist, damp places such as your baby's mouth or on your nipples.
Thrush can develop at any time during breastfeeding, but it is most likely to occur after you or the baby have taken antibiotics. If you have thrush in your nipples, you'll notice burning, itching and flaking. The nipples might also look pink and raw. If you took antibiotics, the good bacteria in your body might have been wiped out along with the bad, causing yeast to grow unchallenged. And because yeast loves warm, moist places, your breastfeeding nipples are prime targets. Luckily thrush normally clears up without medication, so continue to breastfeed as possible. But ask your doctor about antifungal ointment to avoid passing the infection back and forth. Allowing your nipples to air dry between feeding and ensuring any bottles and pacifiers are cleaned and thoroughly dried may help to prevent oral thrush.