Why do Newborns spit up?
Newborns are known to be dependent individuals. They can move and eat but their underdeveloped body systems disable them to function at their optimum maximal functioning. Besides their fragile bones, one body system that one should be highly sensitive of is their digestive tract. It is a fact that the newborn’s gastrointestinal tract is sterile. That is why right after birth, they are injected with vitamin K to stimulate their gastrointestinal tract to function. But aside from that, newborns have small stomach. The capacity of their stomach to accommodate food and liquid is still so limited that they need to be fed several times a day. This is because the size of their stomach can easily get full yet it can also get empty easily.
Because of the mentioned mechanism happening inside an infant’s stomach, spitting up is a common manifestation observed among them. As newborns were studied further, researchers have come to realize that along with the newborn’s immature system is the immaturity of the valve found between the end of the esophagus and the stomach. This valve is known as the lower esophageal sphincter. When this valve matures, the contents in stomach remain in place. However in newborns, they tend to spit up as frequently as expected primarily because this specific valve is not yet functioning well. Otherwise, spitting up may be caused by a reaction to something that has been ingested that seems unlikely to the taste of the infant, the baby is uncomfortable due to an underlying disease or the baby is just simply overly fed.
Spitting up usually peaks when the baby reaches 4 months in age and stops when the infant reaches 12 months, but if spitting up becomes somehow unusual, it is always best to seek medical help.