PCR from urine is the gold standard for the diagnosis of CMV infection. Urine collection is not systematic in newborns and its realization can sometimes be difficult. On the other hand, in children at risk (hypotrophy, prematurity, infectious risks, fetal distress or respiratory distress at birth), gastric aspiration is systematically performed at birth to overcome obstruction of the upper aero-digestive tract, to prevent oesophageal atresia, to avoid inhalation by reflux and sometimes to make a bacteriological diagnosis.