title: Effect of antenatal corticosteroids on morbidity and mortality of preterm singletons and twins.
abstract: OBJECTIVE
  To compare the effect of antenatal corticosteroids (ACS) on neonatal outcomes among singleton and twin pregnancies and the impact of completeness and timing of ministration.
  
  
  METHODS
  Retrospective cohort study involving 951 preterm deliveries (25+0-34+6weeks), between 2006 and 2015. Neonatal outcomes were evaluated according to completeness of ACS ("Complete" n = 441; "Rescue" n = 38; "Incomplete" n = 175; "No ACS" n = 98) and timing of therapy related to delivery ("Before 7 days" n = 260; "After 7 days" n = 181).
  
  
  RESULTS
  On respiratory distress syndrome (RDS), odds ratio (OR) for twins was 0.172, 95% confidence interval (CI) was 0.047; 0.591 and for singletons 0.390 (95%CI 0.214; 0.703) for complete or rescue courses, and 0.280 (95%CI 0.069; 1.066) for twins and 0.906 (95%CI 0.482; 1.698) for singletons for incomplete courses. About the need for mechanical ventilation (MV), twins had an OR of 0.189 (95%CI 0.052; 0.642) and singletons of 0.404 (95%CI 0.222; 0.727) for complete or rescue courses and twins had OR = 0.225 (95%CI 0.053; 0.874) and singletons of 0.404 (95%CI 0.222; 0.727) for incomplete courses. About timing, group "After 7 days" had OR = 2.00 for RDS (95%CI 1.21; 3.30) and 2.32 (95%CI 1.42; 3.78) for MV.
  
  
  CONCLUSIONS
  ACS improves neonatal outcomes both in singleton and twins. Delivering 7 days after a complete course decreased neonatal morbidity.
authors.affiliation: a Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro , Porto , Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Vaz
authors.affiliation: b Department of Obstetrics, Gynecology and Pediatrics , São João Hospital Center , Porto , Portugal.
authors.forename: Maria Filipa
authors.initials: MF
authors.lastname: Malheiro
authors.affiliation: c Epidemiology Research Unit , Institute of Public Health University of Porto , Porto , Portugal.|d Department of Clinical Epidemiology, Predictive Medicine and Public Health , University of Porto Medical School , Porto , Portugal.
authors.forename: Milton
authors.initials: M
authors.lastname: Severo
authors.affiliation: a Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro , Porto , Portugal.|b Department of Obstetrics, Gynecology and Pediatrics , São João Hospital Center , Porto , Portugal.|c Epidemiology Research Unit , Institute of Public Health University of Porto , Porto , Portugal.
authors.forename: Teresa
authors.initials: T
authors.lastname: Rodrigues
authors.affiliation: a Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro , Porto , Portugal.|b Department of Obstetrics, Gynecology and Pediatrics , São João Hospital Center , Porto , Portugal.
authors.forename: Hercília
authors.initials: H
authors.lastname: Guimarães
authors.affiliation: a Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro , Porto , Portugal.|b Department of Obstetrics, Gynecology and Pediatrics , São João Hospital Center , Porto , Portugal.|c Epidemiology Research Unit , Institute of Public Health University of Porto , Porto , Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Montenegro
mesh_terms: D000328:Adult; D001034:Apgar Score; D001623:Betamethasone / Q000008:administration & dosage*; D016022:Case-Control Studies; D003907:Dexamethasone / Q000008:administration & dosage*; D005260:Female; D005865:Gestational Age; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000175:diagnosis / Q000517:prevention & control* / Q000628:therapy; D007273:Injections, Intramuscular; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin; D047928:Premature Birth / Q000401:mortality* / Q000628:therapy; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012189:Retrospective Studies; D013997:Time Factors; D014427:Twins
chemical_list: D005938:Glucocorticoids; D003907:Dexamethasone; D001623:Betamethasone
keywords: Antenatal corticosteroids; morbidity; preterm; twins