title: Delayed lung liquid absorption after cesarean section at term.
abstract: BACKGROUND
  Delayed postnatal removal of lung liquid may result in respiratory distress, which is more common in infants born by cesarean section. Vertical artefacts (B-lines) arising from the lung surface in lung ultrasound have been shown to correlate with the liquid content of the lungs.
  
  
  OBJECTIVE
  We studied whether lung ultrasound could be used for the assessment of postnatal lung liquid in healthy term infants born vaginally and by cesarean section.
  
  
  METHODS
  Lung ultrasound was performed 1, 3 and 24 h after birth to 22 vaginally born infants and 20 infants born by elective cesarean section. The abundance of B-lines was scored for each infant and time point by two independent observers blinded to the mode of delivery and time point on the examination on a five-step scale.
  
  
  RESULTS
  In both groups, a significant decrease in abundance of B-lines, indicative of lung liquid absorption, was observed during the first 24 h. 3 h after birth cesarean section was associated with significantly higher lung liquid content than vaginal delivery.
  
  
  CONCLUSIONS
  The noninvasive bedside ultrasound method for estimation of lung liquid is a promising tool for the early identification of infants at risk for pulmonary maladaptation.
authors.affiliation: Department of Radiology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland. laura.martelius@hus.fi
authors.forename: Laura
authors.initials: L
authors.lastname: Martelius
authors.forename: Cecilia
authors.initials: C
authors.lastname: Janér
authors.forename: Liina
authors.initials: L
authors.lastname: Süvari
authors.forename: Otto
authors.initials: O
authors.lastname: Helve
authors.forename: Kirsi
authors.initials: K
authors.lastname: Lauerma
authors.forename: Olli
authors.initials: O
authors.lastname: Pitkänen
authors.forename: Sture
authors.initials: S
authors.lastname: Andersson
mesh_terms: D000042:Absorption; D001692:Biological Transport; D001826:Body Fluids / Q000378:metabolism*; D002585:Cesarean Section; D005260:Female; D005865:Gestational Age; D006801:Humans; D016014:Linear Models; D008168:Lung / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008297:Male; D015588:Observer Variation; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D011247:Pregnancy; D015203:Reproducibility of Results; D047929:Term Birth; D013997:Time Factors; D014463:Ultrasonography; D014741:Video Recording