How to deal with a 21-day-old baby who only vomits when they make an effort to sleep

Patient's question:

No

Doctor's answer:

At this age, it is common for babies to spit up because their stomachs are in a horizontal position, have a small capacity, and the cardiac sphincter connecting to the esophagus is relatively wide with poor closure. Meanwhile, the pylorus connecting to the small intestine is relatively tight. Additionally, babies often swallow air while feeding, making it easy for milk to reflux into their mouth, causing spitting up.
When a mother first sees her baby spit up, she may be worried and unsure of what to do. However, as long as you pay attention to the following aspects, you can prevent your baby from spitting up.