Causes of Hiccups in Newborn Babies: Hiccups often occur after a newborn is born. This phenomenon often confuses parents. So, why do newborns hiccup? First, choking on milk is a major cause of hiccups. Secondly, it is very common for babies to take in more air when feeding, causing the stomach to bloat. In addition, newborns have small appetites, so they eat frequently. so