Baby Spit Up

Being a new parent is full of surprises, one of which is your baby suddenly expelling milk or formula out of their mouth. Occasional spit-up is common in newborns, and while messy, it’s usually not harmful. Let’s take a look at some typical reasons why babies spit up and when to reach out to your healthcare provider.

What is baby spit-up?

Spit-up is when a baby’s stomach contents, such as milk or formula, come back up the esophagus and out the mouth. One or two mouthfuls may come up during or shortly after feedings or while burping. Larger spit-ups may be a result of overfeeding.

Approximately half of infants will experience spit-up during their first three months. The good news? In most cases, spit-up isn’t harmful, and your baby may be completely unphased by it. In fact, some babies are known as “happy spitters” who may smile or laugh as you reach for a cloth to clean up the wet mess.

What could be causing my baby to spit up?

Babies are prone to spit up for several reasons:


Babies can sometimes consume more than their tiny tummies can hold. What they can’t fit may come back up as a spit-up.

Tip: Smaller, more frequent feedings may help.

Swallowing too much air while feeding

Your voracious little eater may be so hungry that they gulp air while feeding. The air bubbles can build up in your baby’s belly, causing spit-up.

Tip: Try to watch your baby for early hunger cues, such as smacking their lips, and feed them before they begin to cry (another gas-producing culprit) and become agitated.


In addition to eating too fast, gas bubbles can be a result of sucking on a pacifier and using an incorrect baby bottle nipple size. If your baby feeds on a bottle nipple that’s too small, they may swallow too slowly, ingesting air. A bottle nipple that’s too large for your baby’s size may cause formula or milk to flow too fast, resulting in gagging, gas, and spitting up.

Tip: To help avoid and ease gas, ensure the bottle’s nipple flow is appropriate for your baby. When held upside down, the bottle should allow only one quick drop to fall at a time, not a steady stream. Frequent burping can also help get those air bubbles moving up and out.

Their back-lying position

Newborns spend most of their time on their backs, which can trigger reflux.

Tip: After eating, try to keep your baby upright chest-to-chest for at least 30 minutes. Avoid tummy time until at least an hour after feeding.

Remember that even if your baby experiences reflux, they should always sleep on their back for safety reasons.


The world is new to your little one, and they can quickly experience sensory overload. An overexcited baby may gulp too much milk or formula, which may unsettle their sensitive tummy, causing spit-up and gas.

Tip: Keep activity, noise, and visual stimuli to a minimum before feeding.

Your baby’s developing digestive function

In newborns, the muscle that keeps food in their stomach, the lower esophageal sphincter, is still developing. It may not close completely after feeding, allowing a small amount of milk or formula to come back up.

What is normal spit-up?

Expected spit-up is characterized by a tablespoon or two of milk or formula dribbling out of a baby’s mouth, often during a burp. The contents expel fairly gently, and babies are usually not bothered by it.

When should I be concerned about baby spit-up?

Spit-up is typical in infants, and there’s usually no cause for concern if your little one doesn’t seem troubled by it. Occasionally, however, spit-up is accompanied by other issues, which could indicate a potential underlying medical condition. Look for signs such as:

  • Slow to no weight gain, or weight loss
  • Excessive crying, frequent fussiness, and irritability
  • Signs of discomfort, such as arching their back while spitting up
  • Turning away from food
  • Vomiting
  • Diarrhea and other digestive issues
  • Green, yellow, or bloody spit-up
  • Rash
  • Wheezing, coughing, or other respiratory issues
  • Recurrent spit-up after 12 months

Spit-up, along with one or more of the above issues, could be associated with a food sensitivity or allergy, gastroesophageal reflux disease (GERD), or another health condition. For example, some babies may experience spit-up due to a cow’s milk protein allergy, even if they are breastfed. Always consult your pediatrician if you have any concerns about your baby’s spit-up.

Will my baby outgrow spitting up?

As babies grow, spitting-up tends to diminish by 12 months of age. Several factors attributed to this reduction include:

  • A more developed lower esophageal sphincter
  • Increased time spent sitting upright
  • Introduction of solid foods, which can help thicken stomach contents and minimize reflux

Managing baby spit-up

Spit-up is often more upsetting for parents than it is for the baby. If your little one is experiencing spit-up, consider trying the above tips and talking to your pediatrician with any questions or concerns.

If you’re using infant formula, sometimes transitioning to a formula with a thicker consistency can provide some reflux relief—but don’t switch until you check with your doctor. And take heart; while all babies are unique, most outgrow the spit-up stage by their first birthday. Until then, keep a stock of burp cloths on hand and get ready for more messes as your baby grows, plays, and explores their world.

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