title: Respiratory morbidity in late preterm infants.
abstract: BACKGROUND
  Late preterm delivery (74% of all preterm births) increases the incidence of respiratory pathology, namely respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN) and the need of ventilator support when compared to term delivery. The aim is to evaluate the respiratory morbimortality in late preterm infants and the risk factors associated with RDS and TTN.
  
  
  METHODS
  Descriptive retrospective study of all newborns of 34+0 to 36+6 weeks of gestational age, born at our center between September 1, 2012 and August 31, 2015. Those with major malformations, chromosomopathies, hydrops fetalis and congenital TORCH infection were excluded.
  
  
  RESULTS
  A total of 498 newborns were studied, 44 (8.83%) of them with either RDS or TTN. Respiratory morbidity was significantly associated with lower gestational age, male gender, caesarean section, exposure to peripartum antibiotics, overweighed and nulliparous mothers. RDS newborns had a significantly higher need for resuscitation, endotracheal intubation, oxygen therapy, early invasive ventilation, parenteral nutrition and a longer NICU stay when compared to newborns with TTN. 55% of the patients with RDS had 35+0 to 36+6 weeks of gestational age, moderate or severe RDS and required mechanical ventilation; six needed surfactant. Caesarean section and resuscitation with ETT were independent risk factors for respiratory morbidity.
  
  
  CONCLUSIONS
  Late preterm remain at risk for adverse respiratory outcomes, particularly newborns delivered after 35 weeks, whose mothers are not given ACS and still have considerable morbidity. Growing evidence supports the possibility of extending the management window further into the LPT period. Caesarean section was an independent risk factor for respiratory morbidity and efforts should be undertaken to reduce the procedure rate.
authors.affiliation: Faculty of Medicine of Porto University, Alameda Professor Hernâni Monteiro, Porto, Portugal - mimed10081@med.up.pt.
authors.forename: Cláudia
authors.initials: C
authors.lastname: Correia
authors.affiliation: Unit of Neonatal Intensive Care, Department of Pediatrics, Centro Hospitalar São João, Porto, Portugal.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Rocha
authors.affiliation: Faculty of Medicine of Porto University, Alameda Professor Hernâni Monteiro, Porto, Portugal.|Unit of Neonatal Intensive Care, Department of Pediatrics, Centro Hospitalar São João, Porto, Portugal.
authors.forename: Filipa
authors.initials: F
authors.lastname: Flor-de-Lima
authors.affiliation: Faculty of Medicine of Porto University, Alameda Professor Hernâni Monteiro, Porto, Portugal.|Unit of Neonatal Intensive Care, Department of Pediatrics, Centro Hospitalar São João, Porto, Portugal.
authors.forename: Hercília
authors.initials: H
authors.lastname: Guimarães
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007363:Intensive Care Units, Neonatal; D007902:Length of Stay; D008297:Male; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology; D011663:Pulmonary Surfactants / Q000008:administration & dosage*; D012121:Respiration, Artificial / Q000379:methods*; D012127:Respiratory Distress Syndrome, Newborn / Q000453:epidemiology* / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D059245:Transient Tachypnea of the Newborn / Q000453:epidemiology* / Q000628:therapy
chemical_list: D011663:Pulmonary Surfactants