Newborn hiccups are caused by spasms or twitching of the diaphragm, the large muscle located at the base of the lungs that helps with breathing. When the diaphragm contracts involuntarily, it causes a sudden intake of air that leads to the vocal cords closing quickly, producing the characteristic "hic" sound

. Several factors commonly trigger these diaphragm spasms in newborns:

• Feeding-related causes: Eating too quickly, eating too much, or swallowing excess air during breastfeeding or bottle-feeding can cause the baby's stomach to expand and press against the diaphragm, triggering hiccups

. Overfeeding and stomach distension are frequent contributors

• Sudden temperature changes in the stomach, such as feeding something hot followed by something cold, can also provoke hiccups

• Gastroesophageal reflux (GERD) can irritate the esophagus and diaphragm, causing frequent hiccups in some babies

Hiccups are very common in newborns and usually harmless, often occurring during or after feeding. They often resolve on their own without causing discomfort to the baby

. In summary, newborn hiccups are primarily caused by diaphragm spasms often triggered by feeding behaviors like rapid eating, overfeeding, or swallowing air, as well as occasional reflux or stomach temperature changes