(Abstracted from BMJ 2016;354:i4353)
Twin pregnancies are at increased risk of stillbirth. Uncomplicated twin pregnancies are commonly delivered earlier to prevent stillbirth; however, there is a risk of neonatal complications associated with being born prior to 39 weeks’ gestation.
Women’s Health Research Unit, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK (F.C.-S., S. Thangaratinam); Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Utrecht (E.S.); Department of Obstetrics and Gynaecology, Academic Medical Centre, Amsterdam (E.S.), the Netherlands; Stanford Prevention Research Center, Stanford University, Palo Alto, Stanford, CA (E.S.); Clinical Biostatistics Unit, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain (D.A.-M.); Fetal Medicine Unit, St George’s Healthcare NHS Trust, London, UK (A.K., B.T.); Evaluative Clinical Sciences, Women and Babies Research Program, Sunnybrook Research Institute, Toronto, Ontario (J.B.); Department of Obstetrics and Gynecology, University of British Columbia, Vancouver, British Columbia (K.S.J.); Department of Newborn and Developmental Paediatrics, Women and Babies Research Program, Sunnybrook Health Sciences Centre, Toronto, Ontario (E.A.), Canada; Department of Gynaecology and Obstetrics, Diakonessenhuis, Utrecht, the Netherlands (K.H.); Department of Obstetrics-Gynaecology, University Hospitals (L.L.), and Department of Development and Regeneration: Pregnancy, Fetus and Neonate (L.L.), KU Leuven, Belgium; Department of Obstetrics and Gynaecology, Academic Medical Centre, Amsterdam, the Netherlands (A.L., S.L.); University of Edinburgh MRC Centre for Reproductive Health, Queen’s Medical Research Institute, Edinburgh, UK (J.E.N.); Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson, MS (J.M.); Obstetrix Collaborative Research Network, Center for Research, Education and Quality, Mednax National Medical Group, FL (C.A.C., T.J.G., K.M.); University of California Irvine, Irvine, CA (T.J.G.); Maternal-Fetal Medicine Unit, Instituto Valenciano de Infertilidad, University of Valencia (V.S.); Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Valencia, Jefe Servicio Obstetricia Hospital U P La FE, Torre F (V.S., A.P.); Department of Obstetrics, University Hospital La Fe (A.P.), Valencia, Spain; Centre of Fetal Medicine, Department of Obstetrics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark (L.R.); Department of Obstetrics and Gynaecology, Medical University of Vienna, Wien, Austria (K.W.); Department of Obstetrics and Gynaecology, American University of Beirut Medical Centre, Riad El Solh, Beirut, Lebanon (A.N.); The Egyptian IVF Centre, Maadi and Department of Obstetrics and Gynaecology, Faculty of Medicine, Cairo University, Oula, Giza, Egypt (M.A.); Department of Obstetrics and Gynecology, Women and Infants Hospital, Brown University Women and Infants Hospital, Providence, RI (D.R.); Royal College of Surgeons in Ireland, Rotunda Hospital, Dublin, Republic of Ireland (E.T., F.B.); Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Osaka, Japan (S.N.); Department of Obstetrics and Gynecology, University of Milano-Bicocca, Milan, Italy (F.M.R.); Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (J.N.R.); Robinson Research Institute, and Discipline of Obstetrics and Gynaecology, University of Adelaide, North Adelaide, SA, Australia (J.M.D.); Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC (R.B.N.); University of Aberdeen, Dugald Baird Centre for Research on Women’s Health, Aberdeen Maternity Hospital, Aberdeen, UK (S.B.); Department of Obstetrics and Gynecology, Alberta Health Services, Calgary, Alberta, Canada (S. Tang); Australian Research Centre for Health of Women and Babies, Robinson Institute, University of Adelaide, North Adelaide, SA, Australia (B.W.J.M.); and Clinical Biostatistics Unit, Hospital Ramón y Cajal (IRYCIS) (J.Z.), and CIBER Epidemiology and Public Health (CIBERESP) (J.Z.), Madrid, Spain