title: Gestational age at delivery and perinatal outcomes of twin gestations.
abstract: OBJECTIVE
  The optimal gestational duration for twin gestations is unknown. Epidemiologic studies show that the lowest perinatal mortality rate for twins is at 37-38 weeks, but these studies lack information on pregnancy complications and neonatal morbidities. This study evaluates pregnancy characteristics and perinatal outcomes of twins in order to assess the optimal gestational age for delivery.
  
  
  METHODS
  This is a retrospective study of twins delivered at ≥36 weeks at our institution from 1991-2009. The composite rate of perinatal morbidity and mortality (including perinatal death, respiratory distress, suspected sepsis, and need for neonatal intensive care) was determined for weekly intervals from 36-39(+) weeks.
  
  
  RESULTS
  There were 377 twin gestations included. Of those 83% were dichorionic. Fifty-three percent had spontaneous labor and 48% were delivered by cesarean section. Perinatal outcomes improved as gestational age advanced to 38 weeks.
  
  
  CONCLUSIONS
  Perinatal morbidity and mortality rates suggest that the optimal time for delivery of twins is at 38 weeks or greater.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Alabama School of Medicine, Birmingham, AL, USA.
authors.forename: Amy E
authors.initials: AE
authors.lastname: Doss
authors.forename: Melissa S
authors.initials: MS
authors.lastname: Mancuso
authors.forename: Suzanne P
authors.initials: SP
authors.lastname: Cliver
authors.forename: Victoria C
authors.initials: VC
authors.lastname: Jauk
authors.forename: Sheri M
authors.initials: SM
authors.lastname: Jenkins
mesh_terms: D000293:Adolescent; D000328:Adult; D036861:Delivery, Obstetric / Q000379:methods / Q000401:mortality*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D015931:Intensive Care, Neonatal / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D054238:Perinatal Mortality; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D059285:Pregnancy, Twin / Q000706:statistics & numerical data*; D012127:Respiratory Distress Syndrome, Newborn / Q000453:epidemiology; D012189:Retrospective Studies; D018805:Sepsis / Q000453:epidemiology; D055815:Young Adult