Your baby just spit up. Or maybe he vomited. You’re not sure which it was or whether you should be worried. If he spit up, probably not. Baby spit-up isn’t usually an issue.
Also known as reflux, spit-up is simply the flow of food from your little one’s stomach to his mouth.
It’s common, not painful, and might happen from time to time until your baby is about a year old. Baby spit-up is often just the result of a still-developing digestive system or overfeeding.
The difference between spit-up and vomit is outlined below. If you have further questions or concerns, contact your healthcare provider.
Spitting up is a common occurrence in healthy infants early in life. This is partly because of immaturity of their digestive system. It’s relatively harmless and usually resolves as the digestive system matures, when your baby reaches 12 to 14 months of age.
Spit-up is sometimes called by other terms like “regurgitation” and “gastroesophageal reflux.” They’re just fancier ways of saying spit-up, with a minor difference. Regurgitation and reflux refer to the backwards movement of the stomach (gastric) contents up into the esophagus—and at times into the mouth. When the contents of your baby’s tummy spill out of his mouth, it’s called spit-up.
It’s all about tummy size. At birth, your baby’s tummy is about the size of a small marble. After 3 days, it is about the size of a ping-pong ball, but still can’t hold much.1 Until he’s 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.
Babies also have less developed muscles in the upper esophagus, which makes it easier for fluids to flow back up from the stomach.
Spitting up can also happen when your baby burps (called a wet burp) or swallows too much air. It isn’t painful to your baby, and most babies don’t even realize they have done it.
As long as your baby is healthy and gaining weight, spit-up should be seen as just a normal part of his development.
It may look like a lot when it’s on your shirt, but the amount of liquid your baby spits up isn’t as much as you think. Usually, it’s just 1 or 2 tablespoons at a time. If your baby spits up more than this—or if his spitting up is the effect of respiratory events like choking, coughing, or wheezing—ask your pediatrician if there is a reason to be concerned.