Reflux in Preemies

Reflux is common in preemies but is not always obvious. While reflux is often synonymous with spit-up, sometimes preemie reflux only comes part way up the esophagus. This can cause the baby to cough or gag during or after feedings.

Signs of acid reflux in preemies include irritability, refusing to eat, arching their back, and grimacing. Feeding difficulties from reflux in preemies can result in slow weight gain and failure to thrive. Most babies grow out of reflux, though some feeding modifications or treatment may be needed in the meantime.

This article discusses why reflux affects preemies, its common symptoms, and potential complications. It also goes over the diagnostic process and different treatments that may help.

What Causes Preemie Reflux?

Many premature babies are diagnosed, either during or after their NICU stay, with gastroesophageal reflux (GER)—otherwise known simply as reflux. This is when the contents of the stomach move back up through the esophagus because of a relaxed lower esophageal sphincter (LES).

This circular ring of muscle is located at the end of the esophagus. It normally opens to allow food to enter the stomach, but then tightens and closes to prevent stomach contents from going the other way.

With reflux, the LES does not close all the way, allowing the contents of a baby's stomach to come up into the esophagus in small or large amounts. These can be, but aren't always, visible as spit-up or vomiting.

The transient relaxation of the LES is actually a normal phenomenon. But in preemies, the LES can also relax because of:

• Physical immaturity: Having a shorter and narrower esophagus can displace the LES, meaning it isn't in the position it needs to be to work properly.
• Feeding position: Premature infants tend to receive a relatively large volume of liquid feedings while supine (lying on their back). With this position, gravity can't pull milk into the stomach. Instead, some of the milk ends up sitting where the stomach joins the esophagus. Here, the milk is more accessible to reflux back into the esophagus when the LES relaxes.

Preemie Reflux Symptoms and Complications

Reflux in premature infants is known to cause many symptoms, including:

• Significant irritability
• Refusing to eat or only taking very small feedings
• Choking, gagging, or coughing with feedings
• Signs of discomfort when feeding, like back arching or grimacing
• Frequent and/or forceful vomiting

That said, studies have not shown a direct link between these nonspecific symptoms and GER. This means that if a baby is exhibiting any of the above symptoms, one cannot say that it's definitely occurring as a result of GER—there may be something else going on.

In addition to the above symptoms, GER may—perhaps not always directly—lead to various complications, including failure to thrive, esophagitis (inflammation of the esophagus), and lung aspiration.

Research shows that premature babies with GER have longer hospital stays compared to premature babies without the condition. Some of these complications may contribute to this.

Associated Health Conditions

In addition to the above symptoms and complications, GER is linked, albeit controversially, to two health conditions that are may occur in premature babies—apnea and chronic lung disease.

Apnea

Like GER, apnea (when a baby stops breathing) is a very common diagnosis in premature infants. Experts once thought that GER could trigger apnea and associated bradycardia (low heart rate) in premature infants. However, the scientific evidence supporting this link is scant.

In fact, studies have found no temporal connection between GER and apnea/bradycardia. For instance, researchers in one study performed 12-hour overnight studies in 71 preterm infants.

The study found less than 3% of all cardiorespiratory events (defined as apnea greater than or equal to 10 seconds in duration, bradycardia less than 80 beats per minute, and oxygen desaturation less than or equal to 85%) were preceded by GER.

If your baby has both GER and/or apnea, be sure to speak to your healthcare provider about how to best manage these separate conditions.

Chronic Lung Disease

There is some evidence to suggest that GER may be associated with underlying lung disease in premature babies—specifically, those with a lung condition called bronchopulmonary dysplasia or BPD.

The thought is that stomach contents may be aspirated into the lungs and that this could contribute to the worsening of a baby's BPD.

The GER/BPD connection has not been fully teased out. More studies are needed to determine if there is a causal relationship.

When to See a Healthcare Provider

GER is very common in babies, especially preemies, and oftentimes resolves on its own. So if your baby is spitting up a lot but seems happy and is growing, then you can put your mind at ease—this is normal and should pass.

Still, if your baby is exhibiting more worrisome signs or symptoms, it's important to talk with your healthcare provider. Specifically, get a medical opinion if your child:

• Resists feeds
• Chokes on spit-up
• Has frequent or forceful vomiting
• Shows discomfort when feeding (e.g., crying or arching her back)
• Is not gaining weight

In these instances, GER may be the underlying problem or there may be something else going on.

Diagnosis

Most cases of GER in premature infants are diagnosed clinically, meaning the healthcare provider will assess the baby for typical symptoms of GER and also rule out alternative reasons and diagnoses. Possibilities include cow's milk protein allergy, constipation, infection, and neurological disorders.

In some cases, a healthcare provider may recommend a trial of acid-suppressing medication for the baby in order to establish the diagnosis. If it words, GER is likely at play.

Less commonly, diagnostic tests—esophageal pH and multiple intraluminal impedance monitoring—are used to diagnose reflux in preterm babies. These tests can be technically difficult to perform, and the results can be challenging to interpret.

Esophageal pH Probe

This test entails placing a thin tube called a catheter through a baby's nose into the lower part of the baby's esophagus.

At the tip of the catheter is a sensor that can measure the pH of the stomach contents. This information is recorded over a 24-hour period on a monitor that is connected to the catheter.

Multiple Intraluminal Impedance

Multiple intraluminal impedance (MI) also entails placing a catheter into the baby's esophagus. GER is detected by measured changes in the electrical resistance of a liquid bolus as it moves between two electrodes located on the catheter.

This information can help determine whether the bolus is moving antegrade (being swallowed and traveling towards the stomach) or retrograde (being refluxed back from the stomach).

Treatment of Reflux in Preemies

Keeping stomach contents down in the stomach is the goal of treating GER. Many options to help with this exist.

While medication may be recommended, it is typically only suggested after trying other non-medication interventions first.

Positioning

After feeding, many pediatricians recommend keeping your baby in an upright position as much as possible. Keeping your infant in a prone and left-side-down position can also be effective, but only when your baby is awake and being supervised.

When it comes to sleeping, your baby needs to be on their back whether they have reflux or not. In addition, your baby should sleep on a flat and firm mattress that contains no pillows, blankets, toys, or bumpers.

Furthermore, according to the American Academy of Pediatrics, devices used to elevate the head of a baby's crib (e.g., wedges) should not be used. They are not effective in reducing GER and are also dangerous, as they increase the risk of the baby rolling into a position that may cause breathing difficulty.

Milk and Formula

Sometimes, reflux may be related to a baby not tolerating certain proteins in their milk. Mothers who are breastfeeding a preemie with reflux may well be advised to eliminate some common problem foods such as dairy, eggs, soy, or certain meats, as these proteins can pass through breast milk.

When preemies with reflux are fed formula, the same thing may be true—something in the formula may be triggering poor digestion or irritating your baby. In these cases, your healthcare provider may recommend an extensively-hydrolyzed formula, such as Similac Alimentum or Enfamil Nutramigen.

These formulas are technically for babies who cannot digest or are allergic to cow's milk protein, but they may help reduce symptoms in babies with GER as well.

Feeding Adjustments

Research suggests that giving smaller-volume feedings more frequently may be helpful.

Sometimes, parents are advised to use thickening agents such as rice cereal added to milk. Thicker liquids have a harder time getting up and out of the stomach.

However, this practice is being used less often these days due to the concern for an increased risk of necrotizing enterocolitis (NEC) in preterm infants. In fact, it is now recommended that thickeners, such as xanthan gum, not be used in preterm or former preterm infants in the first year of life. 

Reflux Medications

Research has found that acid-suppressing medications do not reduce symptoms of GER. They also increase a premature baby's risk of developing very serious complications, including sepsis, pneumonia, and urinary tract infections.

Side effects may occur as a result of the medication inadvertently altering the "good" bacteria that live in a baby's gut.

As such, the questionable efficacy and safety of these acid-suppressing medications limit their use.

However, your baby's healthcare provider may prescribe an acid-suppressing medication if non-medication therapies (e.g., smaller, more frequent feeds) are not helpful and symptoms are significant.

There are two main classes of medications that are used to treat GER in premature infants:

• Histamine-2 receptor blockers: For example, Pepcid (famotidine)
• Proton pump inhibitors (PPIs): For example, Prilosec (omeprazole) or Nexium (esomeprazole)

Both medications work to decrease acid secretion in the stomach, though through different mechanisms. Reflux is still happening, but it's just not as damaging to the esophagus.

Reflux Surgery

Fundoplication, a surgical procedure in which the upper part of a baby's stomach is wrapped around the LES, is usually only recommended if a baby fails to respond to medication and their reflux is associated with serious and sometimes life-threatening complications.

These complications may include the following:

• Recurrent aspiration pneumonia
• Apneic episodes
• Bradycardia
• Bronchopulmonary dysplasia
• Severe vomiting
• Failure to thrive
• Esophagitis
• Esophageal stricture

Fundoplication can be performed in very small and young babies. In one study, the surgery was performed in infants as young as 2 weeks and as small as 2,000 grams.

Surgery on baby is not something that healthcare providers are quick to recommend. It's really a last resort option, considering potential serious side effects such as:

• Infection
• Perforation: A hole in the intestines
• Tight wrap: When the end of the esophagus is wrapped too snuggly during the surgery, causing problems swallowing
• Dumping syndrome: When food moves from the stomach to the small intestine faster than it should

Summary

Reflux is a common occurrence in premature babies due to their physical immaturity and the position they are typically fed in. It can cause severe irritability and feeding difficulties, but also complications such as failure to thrive and esophagus irritation.

Possible signs of reflux include gagging or an arched back with feedings, refusing the breast or bottle, and spitting up.

Most babies outgrow reflux, but speak to your healthcare provider if you suspect it. Simple changes—or in some cases, medical intervention—can help.