15 days of newborns are not recommended to lie on their stomachs, newborns are still relatively small, various organs and systems are not yet well developed related to the premature let newborns lie on their stomachs can easily lead to asphyxiation hazards, resulting in unnecessary injuries. 15 days of the newborn due to the digestive system is not yet well developed, physiological anatomy, if too early lying down easily due to increased abdominal pressure vomiting or choking symptoms; at the same time, the newborn neck strength is still relatively weak, if lying down can not independently raise their heads or turn their heads, may block the mouth and nose, leading to the child to appear asphyxiation risk. If you let the baby lying down, be sure to have a family member accompanied by, and the time should not be too long. It is recommended that 15 days of newborns usually take the supine position or alternate side position is safer, can promote the normal growth and development of newborns, to avoid bad posture affect the health of newborns.