title: Significance of chorionicity on long-term outcome of low birthweight infants of <1500g in twin pregnancies.
abstract: OBJECTIVE
  The aim of this study was to evaluate the long-term outcomes of very low birthweight twins by chorionicity and to identify the perinatal predictors for outcomes in the era of laser surgery for twin-twin transfusion syndrome.
  
  
  METHODS
  This was a retrospective single-center cohort study of twin pregnancy infants <1500 g from 2003 through 2010. During the study period, laser surgery was performed on cases of twin-twin transfusion syndrome. The composite of adverse outcomes at 3 years of age was defined, including death, cerebral palsy, and developmental delay. The association between perinatal factors and adverse outcomes was evaluated by multiple logistic regression analysis.
  
  
  RESULTS
  A total of 162 infants (79 dichorionic diamniotic twins [DCDA] and 83 monochorionic diamniotic twins [MCDA]) were included in this study. Laser surgery was performed on 11 cases. The rate of adverse outcomes was 13.9% for DCDA and 26.5% for MCDA. The incidence of each outcome for DCDA and MCDA was: cerebral palsy, 1.3% and 4.8%; developmental delay, 8.9% and 9.6%; and death, 3.8% and 14.5%. Gestational age at birth (adjusted odds ratio: 0.69; 95% confidence interval, 0.57-0.84); and anemia at birth (adjusted odds ratio, 10.64; 95% confidence interval, 1.69-66.9) were independent risk factors, whereas chorionicity did not have significance for outcomes.
  
  
  CONCLUSIONS
  The long-term outcome of very low birthweight MCDA was almost identical to that of DCDA. Gestational age and anemia at birth were independent risk factors for adverse outcomes.
authors: Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan.
authors: Hiroshi
authors: H
authors: Kawamura
authors: Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan.
authors: Keisuke
authors: K
authors: Ishii
authors: Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan.
authors: Naoto
authors: N
authors: Yonetani
authors: Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan.
authors: Aki
authors: A
authors: Mabuchi
authors: Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan.
authors: Shusaku
authors: S
authors: Hayashi
authors: Department of Maternal Fetal Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan.
authors: Nobuaki
authors: N
authors: Mitsuda
mesh_terms: D000293:Adolescent; D000328:Adult; D002823:Chorion; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D016015:Logistic Models; D008875:Middle Aged; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin; D012189:Retrospective Studies
keywords: chorionicity; laser therapies; long-term outcome; low birthweight infant; twin pregnancy