<prompt> Apnea of prematurity -10 sec15 sec20 sec30 sec  <response>: Ans. is c i.e., 20 sec o Apnea of prematurity defined as sudden stoppage of breathing that lasts for 20 sec or is associated with bradycardia or cyanosis.Apnea of prematurity should be differentiated from periodic breathing which is normal phenomenon is preterm neonate. 