We hypothesize that low pulmonary expression or activity of ENaC in the perinatal period causes delayed clearance of lung fluid and thereby contributes to the risk for development of transient tachypnea of the newborn (TTN) in term infants born by Caesarean section (CS). The aim of this study is to evaluate whether the respiratory status, measured by a transthoracic ultrasound method and lung compliance, of newborns infants born by CS can be improved by inhaled salbutamol at 30-60 minutes of age. 62 infants will be included and randomized to receive salbutamol or placebo-inhalations in a double-blind manner.