Newborns hiccups when they are full may be physiological phenomenon, or it may be caused by improper feeding, indigestion and other reasons. 1. Physiological phenomenon: when a newborn baby eats milk, it may eat a certain amount of air, which causes diaphragmatic spasm, resulting in hiccups, which will be relieved after the air is expelled. 2. Improper feeding: the newborn may be fed when he/she cries or in an incorrect position, which causes the newborn to swallow a lot of air and cause hiccups. 3. Indigestion: If a newborn eats too much milk, it can easily cause indigestion. A large amount of milk accumulates in the stomach, which produces a certain amount of gas and leads to hiccups, which are often accompanied by a sour odor. Newborns hiccups after eating, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to determine the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.