Why Do Babies Get Thrush in Their Mouth? – Facts Every Parent Should Know

Thrush or white tongue can appear in newborn babies for the first few weeks or months after birth. This is caused by Candida, a yeast infection that thrives in the mouth. Sometimes due to prolonged sucking, the lining in a baby’s mouth also gets irritated. And since babies have a weaker immune system, his body may not be able to resist this yeast overgrowth. Thrush may be discomforting for babies, but it is very treatable.

Everything was going amazing with your newborn – he seemed relaxed, happy, and content. Until one day, your voracious little one suddenly dislikes his feeding time.

Worst of all, he’s got all these white patches on his tongue, and he’s beginning to get cranky. Mommies from your support group say it is oral thrush and that you need a trip to the doctor. But what else do you know about it?

Symptoms of thrush

Don’t freak out if you see white specks on your infant’s mouth just yet. Sometimes, what you think is an infection is actually just milk residue. It’s because both thrush and milk residue on a newborn’s mouth takes on a similar appearance.

The difference is that you can easily wipe away the residue with a damp cloth; otherwise, it is a thrush.

The telltale signs of thrush include:

  • White patches in baby’s gums, tongue, inside cheeks, and roof of the mouth
  • Redness of mouth
  • Decrease sucking
  • Fussiness
  • Cracking mouth corners

Candida can grow on all moist parts of his body, so often, diaper rash is also present. This is characterized by red dots of rash. Some babies may not show any mood changes at all, except during feeding.

If you are a breastfeeding mom, you are likely to experience its symptoms on your nipple as well.

You will have a flaky, cracked, and itchy nipple that appears in a deep pink color. Your breast will also feel sore with burning pain during or after nursing.  

What causes thrush?

You may wonder where you went wrong. You’ve been very keen and clean with the baby’s stuff – sterilizing and everything. So how did these culprits even make their way to your infant’s mouth?

Fungi, specifically the yeast Candida albicans, naturally inhabit our mouth. It is our immune system that prevents its overgrowth. But in babies with immune systems who are not yet fully developed, their chance of thriving is high.

These yeasts are not only responsible for oral thrush infection but also diaper rash in the nappy area.

Thrush also occurs in babies if you have been previously treated with antibiotics during pregnancy. For example, vaginal yeast infection is prevalent among expecting women, and doctors often recommend antibiotics to stupor its growth.

These antibiotics kill the bacteria at the onset of your pregnancy but may allow the yeast to proliferate instead. As a result, your baby likely encountered Candida in the birth canal.

If for some reason, your baby was treated with antibiotics right after birth, he may exhibit the symptoms as well.

Sucking is also one possible cause of thrush, either from bottle-feeding, pacifier use, or even breast-feeding. The increased friction can irritate and cause abrasion in his tongue, where yeast would later feast on.


Premature babies have a higher risk of developing oral thrush. Newborns from four to eight weeks of age are also at risk, but this could also happen even to older babies.

According to St. Louis Children’s Hospital, it occurs in five percent of healthy newborn babies.

Thrush in itself is not contagious, but it can be passed between mother and baby. The incubation period of this yeast is around two to five days. Its symptoms may last for up to two weeks without treatment.

Oral thrush infection treatment

An infant’s thrush can go away on its own for a few days. He may not need any treatment for it. However, since experiencing thrush symptoms can be upsetting, proper treatment helps hasten his recovery.

Your healthcare provider may recommend an antifungal gel or drops to treat it. Breastfeeding mothers will also undergo simultaneous treatment with the baby even if she does not have any symptoms.

Just a caveat though: never use any medicine on your baby without asking your pediatrician first.

There are a lot of over-the-counter medicines and creams available for thrush treatment.

Some doctors may recommend Nystatin oral suspension to clear the baby’s thrush in as early as two days. But you need further advice since you should complete this suspension for seven days even after the symptoms have cleared.

Nipple thrush treatment for breastfeeding moms

Nipple Thrush Treatment for Breastfeeding Moms

Babies will likely pass the yeast infection to their moms’ breasts during breastfeeding.

Even if you do not have symptoms, doctors will recommend that you treat your nipple for it. If you do have symptoms, the burning pain itself will require an immediate cure.

Breastfeeding your baby when you have nipple thrush is perfectly okay. What’s hard to handle is the shooting pain that comes with it. Your areola will become red and swollen, that you will also abhor feeding time more than your infant.


There are over-the-counter medicines available for treating nipple thrush. Nystatin or Gentian Violet may also be effective not just for your baby’s mouth but for your nipple as well. If you want to get rid of thrush naturally, you can use diluted apple cider vinegar as a topical solution.

Another thing to remember if you have nipple thrush is to stop feeding your baby with frozen breast milk. You can still breastfeed a baby even if both or either of you has thrush.

Breast milk contains substances that help delimit and naturally treat an infant’s thrust. But you should never store and feed him with frozen breast milk.

Freezing does not kill the yeast in it, so it may only cause re-infection. If you need to, you can boil frozen milk before feeding. Moreover, always remember to wash your hands before handling your baby and his stuff.

How do you prevent thrush?

Since Candida inhabits everywhere and with anyone, there’s no way to prevent it from being there in the first place.

The least you could do is to stop it from growing and spreading is by cleaning or brushing your baby’s mouth regularly. Thrush can stay in your baby’s toothbrush. Hence, you need to change it immediately during and after treatment.

Here are some reminders that may help:

  • Clean the baby’s mouth daily with a soft and clean cloth or gauze. Wrap it around your finger and dab in lukewarm water. Gently rub this in his tongue, gums, the roof of his mouth, and his inside cheeks. 
  • If your baby is on formula, sterilize all his stuff from nipples, bottles, pacifiers, teething rings, and your breast pump. Boil it for at least 10 minutes each day after washing.
  • If you are breastfeeding, wash and dry your nipples thoroughly before feeding. And if you have a yeast infection, remove medication before feeding and just reapply it afterwards.  
  • Wash your baby’s hand frequently, especially if he is constantly putting his hand on his mouth.
  • For your baby’s diaper rash, wash his nappy area with lukewarm and mild soapy water. Don’t use antibacterial soaps as this may cause an allergic reaction and make matters worse. Pat until dry with a clean towel, or you can use a hair-dryer on a low setting. Exposing your baby’s bottom to air can help inhibit the growth of yeast.

When to visit the doctor

When to visit the doctor for your baby's thrush

While thrush eventually heals on its own, this is very upsetting to babies. It may also affect his feeding and take a toll on his health and nutrition.

Severe conditions need immediate medical attention. It is highly advisable to get your doctor’s prescription to make it easier for you and your infant.

Natural remedies like Gentian violet, coconut oil, baking soda, or probiotics are suggested to be effective for thrush. But depending on your baby’s age, these products have limitations and side effects.

Discuss this with your health care provider if you want to use these products.

If the medication does not clear the symptoms away in seven days, then you need a doctor’s reappointment.


Babies are born with fungi called Candida that can cause thrush in the early stage of their lives. It will usually go away on its own but may cause him discomfort. Sterilizing and sanitary handling of baby items is a must and effective prevention. Brushing and regular cleaning of the baby’s tongue can stupor the growth of these stubborn yeasts as well.

Thrush in a baby’s mouth is not contagious to other people. But he may pass it on to his mother’s breast or vice versa. So both mother and baby need to undergo treatment at the same time to prevent re-infection.

Topical creams and gels are effective in treating thrush. While most of it is available over-the-counter, a doctor’s advice is still necessary, especially for very young babies.

It’s okay; these things can happen to your child as his immune system is still vulnerable. But don’t let these matters steal a moment from your bonding with your newborn.

Although you cannot truly protect him from fungi and bacteria invasion, prevention and early management will always help.

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Ann Marie is a licensed nurse in the Philippines. She experienced handling and assisting deliveries of newborns into the world. She also trained in labor rooms and pediatric wards while in nursing school - helping soon-to-be mothers and little kids in the process. Though not a mother by nature but a mother by heart, Ann Marie loves to take care of her younger cousins as well as nephews and nieces during her free time.

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