<qa>  What is the cause of intermittent hypoxemia?Preterm birth is a major health care concern and although survival of premature infants has improved, the incidence of neonatal morbidities has slightly decreased especially in cases of extreme prematurity. Apnea of prematurity immature respiratory control is a major complication in Neonatal Intensive Care Units occurring in virtually all infants born before 28 weeks gestation. Intermittent Hypoxemia IH, episodic oxygen desaturation events, is generally attributed to apnea of prematurity often superimposed upon suboptimal lung function. Intermittent hypoxemia events are common in preterm infants and may lead to both short-term and long-term morbidities. Typically, the incidence of intermittent hypoxemia IH increases over the first 4 weeks of life before plateauing at weeks 6-8. In addition to inducing oxidative stress by increasing production of reactive oxygen species, this hypoxemiareoxygenation cycle is thought to induce a pro-inflammatory cascade of transcription factors that promotes activation of inflammatory cells resulting in multisystem morbidity. These morbidities include retinopathy of prematurity, cardiorespiratory instability, and poor neurodevelopmental outcomes. A potential morbidity that has yet to be investigated is acute kidney injury AKI. 