TTN stands for Transient Tachypnea of the Newborn, which is a respiratory disorder that affects newborn babies. It is a short-lived condition of fast breathing that usually starts within 2 hours of birth and lasts less than 24 hours. TTN is caused by a delay in the clearance of fetal lung fluid after birth, which leads to ineffective gas exchange, respiratory distress, and tachypnea. Babies with TTN have extra fluid in their lungs because it failed to clear as expected, so they must breathe faster and harder to get enough oxygen. TTN is more common in premature babies because their lungs are not fully developed, and in babies born by rapid vaginal deliveries or C-sections without labor. Babies with TTN are closely watched in the hospital, and some might need extra oxygen for a few days. However, most babies make a full recovery, and TTN usually does not have any lasting effects on a childs growth or development.