Seeing your baby spit up through their nose can be alarming, but this event, known as nasal regurgitation, is often a benign symptom of common infant reflux. This involuntary return of stomach contents is related to an underdeveloped digestive system and specific anatomical connections in a baby’s head and neck. While distressing, it is typically a temporary issue that most infants outgrow as their bodies mature. Understanding the underlying mechanisms helps manage this common occurrence.
How Spit Up Enters the Nasal Passage
The anatomical connection between the mouth and the nose explains why regurgitated milk exits through the nares. Both the mouth and the nasal passages connect at the pharynx, or the back of the throat. This area is a shared pathway for breathing and swallowing.
The soft palate, a muscular structure at the roof of the mouth, normally seals off the nasopharynx—the upper part of the throat leading to the nose—during swallowing. This closure prevents food or liquid from traveling upward.
When an infant experiences reflux, stomach contents are expelled up the esophagus and into the pharynx. If the spit-up is forceful, or if the baby’s mouth is closed, the soft palate may fail to completely seal the nasopharynx. The liquid then takes the path of least resistance, flowing up and out through the nasal cavity.
Factors That Cause Infant Reflux
The primary reason infants spit up is the immaturity of their digestive system. The lower esophageal sphincter (LES), a muscular ring acting as a valve between the esophagus and the stomach, is often weak in the first few months of life. This undeveloped muscle allows stomach contents to easily flow backward, a process known as gastroesophageal reflux (GER).
A baby’s stomach capacity is relatively small, and overfeeding easily exceeds its limits, causing the excess volume to be expelled. Infants also spend most of their time lying flat. Their stomach is positioned more horizontally than an adult’s, making it easier for liquid to escape.
Excessive air swallowing during feeding, known as aerophagia, contributes significantly to reflux. This trapped air forms a bubble that rises in the stomach and forces the milk or formula back up. Fast milk flow from a bottle or a vigorous let-down during breastfeeding can cause gulping and a higher intake of air.
Simple Strategies to Reduce Spit Up
Adjusting feeding practices is the most effective way to minimize the frequency and volume of spit-up. Keeping the baby in an upright position during feeding helps gravity keep the contents in the stomach. This position should be maintained for at least 20 to 30 minutes after the feeding is complete.
Manage the volume of the feeding by offering smaller amounts more frequently throughout the day. If bottle-feeding, ensuring the nipple has an appropriate flow rate prevents the baby from gulping and swallowing excess air.
Frequent burping during the feeding helps release trapped air before it contributes to reflux. Burping a bottle-fed baby after every one or two ounces can be beneficial. Avoiding tight clothing around the baby’s abdomen also prevents pressure on the stomach that could trigger regurgitation.
When to Seek Medical Advice
While most nasal regurgitation is harmless, certain signs indicate a more involved health issue requiring professional evaluation. A primary concern is a failure to gain weight or a noticeable weight loss. If the baby is not retaining enough calories to support healthy growth, a doctor should be consulted immediately.
Symptoms of pain or distress are significant red flags, such as excessive fussiness, arching the back during or after feeds, or refusing to eat. Projectile vomiting should be evaluated to rule out conditions like pyloric stenosis. Additionally, if the spit-up contains blood, or is green or yellow in color, this suggests an issue beyond typical reflux.