(Abstracted from JAMA Pediatr 2017;171(7):678–686)
Prenatal administration of antenatal corticosteroids (ANSs) reduces neonatal morbidity and mortality in preterm infants and is recommended for women at risk of delivery before 34 weeks' gestation. There is consensus that neonatal benefits are maximized when ANSs are administered 24 hours to 7 days before delivery, but the latest point at which ANSs can be used effectively is unknown.
Division of Pediatrics, Department of Clinical Science, Intervention, and Technology, Karolinska Institutet (M.N., E.W.); Department of Neonatal Medicine, Karolinska University Hospital (M.N., E.W.), Stockholm, Sweden; INSERM Joint Research Unit 1153, Obstetrical, Perinatal, and Pediatric Epidemiology Research Team (Epopé), Center for Epidemiology and Statistics Sorbonne Paris Cité, University Hospital Department Risks in Pregnancy, Paris Descartes University, Paris, France (A.P., J.Z.); Departments of Neonatology (K.B., O.P.) and Obstetrics (L.D.H., T.W.), Hvidovre University Hospital, Hvidovre, Denmark; Department of Women's and Children's Health, and Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden (A.-K.E.B.); Departments of Population Health Science and Policy and Obstetrics, Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai, New York, NY (E.A.H.); University Paris Descartes and Department of Neonatal Medicine and Intensive Care Unit of Port-Royal, Cochin University Hospital, Assistance Publique-Hôpitaux de Paris, France (P.-H.J.); Children's Hospital, University Hospital, Philipp University of Marburg, Marburg, Germany (R.F.M.); Tallinn Children's Hospital, Tallinn (L.T.); University of Tartu (L.T.) and Tartu University Hospital, University of Tartu (H.V.), Tartu, Estonia; Department of Neonatology, Radboud University Medical Center, Nijmegen, the Netherlands (A.V.H.); Research Unit of Perinatal Epidemiology, Clinical Care and Management Innovation Research Area, Bambino Gesù Children's Hospital, Rome, Italy (M.C.); Department of Neonatology, Poznan University of Medical Sciences, Poznan, Poland (J.M.); Epidemiology Research Unit, Institute of Public Health, University of Porto, Porto, Portugal (H.B.); Department of Neonatology, Antwerp University Hospital, University of Antwerp, Antwerp, and Study Centre for Perinatal Epidemiology Flanders, Brussels (P.V.R.), Belgium; and Department of Health Sciences, University of Leicester, Leicester, England (E.S.D.)