Baby spit-up usually is not an issue, however baby vomiting can be harmful as it might trigger dehydration.

Learn how to tell the difference between spit-up and vomit, and when there is too much of either one. If you remain concerned after learning about the differences between spit-up and vomit, contact your healthcare provider.

What is spit-up?

Spit-up, also called reflux, is the flow of food from the stomach to the mouth  is a common occurrence in healthy infants early in life, partly because of gut immaturity. Often, it is simply the result of a still-developing digestive system or overfeeding. Nonetheless, it is relatively benign and usually self-resolving by 12 months of age.

The terms “regurgitation”, “spit-up”, and “gastroesophageal reflux” are often used interchangeably. “Regurgitation” refers to the effortless backup movement of the stomach (gastric) contents into the oesophagus—and at times into the mouth. “Spit-up” refers to when the stomach contents are visibly spilling out of the mouth.

Regurgitations or reflux that are not spilled out of the mouth are sometimes called “ghost spit-ups”.

Why do babies spit up?

At birth, your baby’s tummy is about the size of a small marble. After three days, it is about the size of a ping-pong ball, but still can’t hold much.¹

Until about 4 months old, your baby’s tummy can hold only small amounts of milk at a time. Too much milk during feedings can cause your baby to spit up or be fussy.

Spitting up can happen when your baby:

• Burps (called a wet burp)
• Eats too much
• Swallows too much air

There is no reason to worry about these common causes of spitting up. It is not painful to them, and most babies don’t even realise they have done it. As long as your baby is healthy and gaining weight, it is simply part of the development process.

It might seem like a lot, but the amount of liquid your baby spits up might not be as much as you think. If your baby spits up more than 1 or 2 tablespoons at a time (or if spitting up is associated with respiratory symptoms such as choking, coughing, or wheezing), ask your healthcare professional if there is a reason to be concerned.

How is baby spit-up different from vomit?

If spitting up is making your baby uncomfortable, and gets more forceful with more volume than usual, it might mean it is vomit.

When babies vomit more than once, it is usually caused by a virus that includes diarrhoea. Although these viruses usually are not dangerous, they can cause dehydration.

Because babies younger than 1 year old are at greater risk of dehydration, consult your healthcare professional immediately if you think your baby might be dehydrated.

When should you be concerned about your baby vomiting?

Although it can be alarming, an occasional vomiting episode is usually not cause for concern. Frequent baby vomiting can indicate reflux disease, intestinal obstruction, infection, or a protein allergy. Contact your healthcare professional if your baby’s usual spit-up:

• Increases in volume or force
• Causes choking episodes or respiratory difficulty (wheezing or coughing)
• Leads to other issues (discomfort, fussiness, poor weight gain, or weight loss)
• Accompanied by a fever, diarrhoea, bloody mucus in the vomit, or a bloated abdomen
• Green or yellow
• Frequently projectile

Sometimes repeated vomiting in babies can be a sign of a blockage at the stomach. Contact your healthcare professional if your baby vomits repeatedly.

Baby vomiting as a sign of dehydration

When babies have sudden bouts of vomiting associated with diarrhea, it is usually caused by a virus. Although these viruses usually are not dangerous, they can lead to dehydration, which can be a serious problem. It is important to know the signs of dehydration and what you can do to prevent it.

Signs of dehydration to look for are when your baby:

• Has fewer wet diapers than normal
• Seems very tired or weak
• Has tearless, sunken eyes, dry skin, and little saliva

The younger your baby, the greater the concern for dehydration. While she is ill, it is important to replace the fluids your baby is losing with small, frequent feedings. In many cases, an oral rehydration solution is recommended. Check with your healthcare provider for advice.

References:
¹ Spangler AK, et al. J Hum Lact. 2008;24:199-205.