Why Do babies Spit Up Breast Milk and Formula?

As a parent, it's totally normal for you to worry about your little one, and oftentimes it can seem like there is an endless list of things for you to stress about. A common source of anxiety amongst parents is wondering why their baby is spitting up.

It's absolutely understandable that watching your baby spit up may cause you distress. On top of that, you're likely worried about whether or not your baby is getting enough food and odds are that you're getting pretty tired of cleaning up your baby, yourself, and whatever else has fallen victim to being the target of your baby's spit-up.

You're probably thinking to yourself, it's a bad sign that your baby's food isn't staying down, isn't it? Well to put some of your fears to rest, for most babies, spitting up also known as infant reflux, is totally normal and not a cause for concern.

In this article we'll walk you through why exactly spitting up is so common amongst babies, what kind of spit-up falls within the realm of being normal, tips and tricks on how you can help reduce it, and red flags to keep an eye out for!

Why Do Babies Spit Up After Eating?

Most of the time, it's very normal for babies to spit up after a feeding, and in some cases, after every feeding. In fact, about half of all infants will experience spitting up during their first three months of life. Doctor's have even coined a clever expression to describe normal spit-up in infants, they call these little ones ''happy spitters''.

A Happy spitter is still thriving, growing well, generally content and comfortable, and doesn't have any vomiting-related breathing problems but does deal with spitting up. But why is this the case? Typically it comes down to your infant's digestive system not yet reaching maturity.

You see, when your baby feeds on either breast milk or formula, the milk first journeys down your baby's throat, then it makes its way to the esophagus, and the final destination is your baby's tummy.

Now thankfully, our bodies are built with a handy mechanism known as the lower esophageal sphincter, you can think of it as a little gateway that keeps our stomach contents where they belong, in our tummies!

The problem though is that this gateway isn't as efficient as it should be before 6 months of age when your baby's digestive system is still undergoing development.

So while theoretically, your little one's stomach should be milk's last stop, the reality is that milk often finds its way back through the gate then up and out for your baby's mouth. This is often especially true if your baby eats too much or too quickly because once their tiny tummy fully fills up, the only place left for the rest of the milk to go is out!

Learn more: Baby Feeding Chart: Recommendations for the First Year of Life

Ultimately, whether your baby is breastfed or formula-fed, or they take a combination of both, there's a good chance that your baby spits up and in most cases, an underdeveloped lower esophageal sphincter is the culprit. But can the causes of spit-up differ depending on what your baby drinks? Read on to learn more!

Why Do Babies Spit Up Breast Milk?

For breastfed babies, spit-up can sometimes be related to your infant having sensitivities or allergies to certain foods in your maternal diet. These allergens can then be passed on to your child through nursing which can provoke spit-up. In such very rare cases, your child's pediatrician may recommend that you eliminate dairy products or other foods from your own diet.

Alternatively, if you have either an overabundant milk supply or a strong let-down reflex, this can increase the amount of air that your baby takes in while feeding.

The combination of gulping down large amounts of air and milk at the same time can cause spit-up. You can usually help prevent air from mixing with your baby's stomach contents if you regularly burp your baby both during and after feedings.

Why Do Babies Spit Up Formula?

Akin to some breastfed babies having allergies to human milk, occasionally formula-fed babies may have milk/soy protein intolerance or allergy which can lead to your baby spitting up their formula. In such cases, it's best to reach out to your baby's doctor as they can suggest a formula without these ingredients.

Learn more: When to Use Hypoallergenic or Special Formula?

Furthermore, air can also be a culprit of spit-up for bottle-fed babies. If you bottle-feed your little one, it's important to choose a baby bottle with an adequately sized nipple hole.

If you go for a nipple that's too small, it can cause air bubbles that fill your baby's stomach up with swallowed air. When you hold your baby's bottle upside down, their formula should ideally flow at a rate of one drop per second. A deep clean or slight widening of the nipple should help to combat this issue!

What is a Normal Amount of Spit-Up?

Alright, so now we know that spitting up in babies is very common, but how can you tell how much spit-up is normal? Well, it's important to mention that when it comes to baby spit-up, normal amounts vary widely.

Your little one may experience anywhere from a couple of dribbles down their chin to soaking your entire shirt sleeve, it largely depends on the individual baby. However, if you're looking for an exact quantity to go off of, normal spitting up usually produces between one and two tablespoons of spit-up.

We know it can be scary when the amount of spit-up looks like more than it is, but keep in mind that if your baby is healthy, growing, comfortable, and gaining weight there is likely nothing to worry about. If you're ever concerned about the amount, be sure to reach out to your baby's doctor.

What Is The Difference Between Spitting Up And Vomiting?

While spit-ups are a common occurrence amongst many babies, true vomiting is a different story. Vomiting is usually a symptom of an underlying illness, as such, it often appears alongside other symptoms such as diarrhea or fever. We'll walk you through the important differences between the two so you know what's what!

Spitting Up

Most spit-ups begin with a burp and then milk will gently dribble out of your baby's mouth. In terms of coloration, it can change slightly from day to day but in general, it should be either cream, white, or slightly yellow.

When your little one spits up, even after each time you feed your baby, it's often not an issue. If your baby is going to spit up, generally the condition will present itself before 6 months of age and you'll be happy to hear that most babies stop spitting up by 12 months of age.

Vomiting

On the other hand, vomiting occurs forcefully and will commonly shoot out of your infant's mouth and is accompanied by a retching sound. Your baby's stomach vile will typically tinge the vomit slightly green.

Most infants will vomit every once in a while, but if you find your baby is vomiting repeatedly, for more than 24 hours, or if the color is red or green it's important to contact your baby's pediatrician right away as it could be a sign of a serious health issue.

Other red flags that necessitate seeking medical attention include poor weight gain, dehydration, pain or discomfort, and if your baby is inconsolable.

Can Spitting Up Be a Sign of a Problem?

While spit-up is very common in healthy babies, it's not always smooth sailing. Occasionally, other symptoms can point toward a more serious issue than just day-to-day spitting up. If you notice any of the following signs in your child, be sure to reach out to your baby's pediatrician:

• Not gaining weight

• Spits up forcefully

• Projectile vomiting

• Has fewer wet diapers

• Spits up brown, green, or yellow fluid

• Spitting up starts at 6+ months of age

• Continually refuses their feeding

• Increased irritability

Gastroesophageal Reflux Disease

For some babies, gastroesophageal reflux disease (GERD) may be the culprit of their spit-up. When the sphincter in a baby's esophagus doesn't immediately close up after opening, the term ''acid reflux'' is used to describe the spit-up coming back up alongside stomach acids and juices. Symptoms of GERD include...

• Refusing feedings

• Crying or appearing in pain during a feeding

• Wheezing

• Coughing

• Swollen or hard belly

• Increased intensity or occurrence of spitting up

• Spit-up contains blood or is greenish in color

If you notice any of these symptoms, as well as poor growth or inability to gain weight, be sure to reach out to your baby's doctor to determine if GERD may be the root cause of your baby's spitting up.

What Can You Do To Reduce Spitting Up?

Infant reflux is no fun for anyone, but the good news is that there are some things you can do to help reduce spitting up! We've prepared a top 5s list of some things you can do to help. As always, make sure to consult your pediatrician to find the best strategy for your baby!

1. Avoid placing your baby on their stomach to sleep - According to the American Academy of Pediatrics, the best sleep position for a baby is on their back. Back sleeping helps to prevent SIDS and may reduce the incidence of spit-up!

2. Hold your baby upright after feeding - Holding your baby in an upright position after feeding helps to prevent milk from coming back up. For the best results, be sure to hold them upright for at least 20 to 30 minutes

3. Make feeding synonymous with calm - By avoiding active play, limiting noise, and bright lights during feeding time you can help create more calm for your baby, which may work to reduce spitting up.

4. Avoid overfeeding your baby - According to the American Academy of Pediatrics, parents should wait for a minimum of two and a half hours between formula-feedings and at least two hours for breast-feedings. This will help your little one's stomach to empty before adding more milk to it

5. Burp your baby - When feeding your infant make sure to hold your baby's head higher than the rest of their body and burp your baby during and after feedings to remove air from their belly, FYI bottle-fed infants tend to be more prone to swallowing air and may need more burping.

Conclusion

For many healthy babies, spitting up is just a normal part of the course. While it can certainly be a nuisance to you who's constantly changing you and your baby's clothes, it's oftentimes not a cause for concern.

As long as your little one is gaining weight well and they aren't displaying any concerning symptoms in conjunction with their spit-ups, everything is most likely A-okay! But there certainly are cases in which spitting up crosses the line into abnormal, or in which it's actually vomiting. So if you're ever in doubt about what is and is not normal for your baby, make sure to reach out to your baby's pediatrician!

Sources

• Spitting up in babies. Family Doctor. May 14, 2020. 

• Your baby: Spitting up and vomiting. Web MD. August 21, 2020. 

• Why babies spit up. Healthy Children. April 09, 2019.   

• Spitting up - Reflux. Seattle Children’s Hospital. 2022.