title: Perinatal complications in twin pregnancies after 34 weeks: effects of gestational age at delivery and chorionicity.
abstract: OBJECTIVE
  To evaluate the perinatal outcome of twins approaching term in relation to chorionicity and gestational age at delivery.
  
  
  METHODS
  We accessed data pertaining to a cohort of 471 twin pregnancies with certain chorionicity delivered at > 34.0 weeks' gestation. Twin gestation per se, estimated fetal weight below the 10th percentile, or any intertwin discordance was not an indication for delivery before 40.0 weeks. Predictors of adverse perinatal outcome were identified using logistic regression analysis.
  
  
  RESULTS
  There were no stillbirths. Adverse neonatal outcome occurred in 27% of monochorionic versus 16% of dichorionic gestations. At multivariate analysis, lower gestational age at delivery (odds ratio [OR] 0.70, 95% confidence interval [CI] 0.57 to 0.87), monochorionicity (OR 2.06, 95% CI 1.16-3.63), and either twin being growth-restricted (OR 2.35, 95% CI 1.22 to 4.54) were independent predictors of adverse neonatal outcome. Analysis of adverse neonatal outcome stratified by gestational age and chorionicity identified 36 to 37 weeks as optimal timing for delivery of monochorionic twins, and dichorionic twin pregnancies should be allowed to continue until term.
  
  
  CONCLUSIONS
  Among twin gestations delivered after 34 weeks with appropriate fetal growth, reassuring fetal status at weekly assessment, and absence of obstetric complications, delivery after 36 weeks for monochorionic twins and at term for dichorionic twins minimizes the risk of stillbirths and neonatal morbidity.
authors.affiliation: Department of Obstetrics and Gynecology, University of Milano-Bicocca, Monza, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Vergani
authors.forename: Francesca Maria
authors.initials: FM
authors.lastname: Russo
authors.forename: Ilaria
authors.initials: I
authors.lastname: Follesa
authors.forename: Sabrina
authors.initials: S
authors.lastname: Cozzolino
authors.forename: Tiziana
authors.initials: T
authors.lastname: Fedeli
authors.forename: Luisa
authors.initials: L
authors.lastname: Ventura
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ghidini
mesh_terms: D000328:Adult; D002823:Chorion; D005260:Female; D005317:Fetal Growth Retardation / Q000209:etiology; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin; D012189:Retrospective Studies