title: Antenatal factors associated with significant birth weight discordancy in twin gestations.
abstract: OBJECTIVE
  The purpose of this study was to evaluate factors that are associated with significant birth weight discordancy.
  
  
  METHODS
  As a part of an ongoing collaborative study of twins, maternal and fetal data were obtained from the medical records of twin gestations at eight medical centers. The study population was divided into groups by difference in birth weight discordancy (>or=20%, >or=25%, and >or=30%)
  
  
  RESULTS
  Severe birth weight discordancy was associated with fetal growth deceleration by 20 to 28 weeks (adjusted odds ratio, 4.90; 95% CI, 3.15-7.64) and between 28 weeks to birth (adjusted odds ratio, 3.48; 95% CI, 1.72-7.06). Antenatal bleeding (adjusted odds ratio, 1.86; 95% CI, 1.08-3.21), preeclampsia (adjusted odds ratio, 1.70, 95% CI, 1.21-2.41), and monochorionicity (adjusted odds ratio, 2.35, 95% CI, 11.71-3.23) were also associated with birth weight discordancy.
  
  
  CONCLUSIONS
  These data demonstrate the importance of the early diagnosis of placental chorionicity, because monochorionicity is associated with a 2-fold increase in birth weight discordancy in twin gestations.
authors.affiliation: University of Miami, FL 33101, USA. vhgonzalez@med.miami.edu
authors.forename: Vctor H
authors.initials: VH
authors.lastname: González-Quintero
authors.forename: Barbara
authors.initials: B
authors.lastname: Luke
authors.forename: Mary J
authors.initials: MJ
authors.lastname: O'sullivan
authors.forename: Ruta
authors.initials: R
authors.lastname: Misiunas
authors.forename: Elaine
authors.initials: E
authors.lastname: Anderson
authors.forename: Clark
authors.initials: C
authors.lastname: Nugent
authors.forename: Frank
authors.initials: F
authors.lastname: Witter
authors.forename: Jill
authors.initials: J
authors.lastname: Mauldin
authors.forename: Roger
authors.initials: R
authors.lastname: Newman
authors.forename: Mary
authors.initials: M
authors.lastname: D'alton
authors.forename: David
authors.initials: D
authors.lastname: Grainger
authors.forename: George
authors.initials: G
authors.lastname: Saade
authors.forename: Gary
authors.initials: G
authors.lastname: Hankins
authors.forename: George
authors.initials: G
authors.lastname: Macones
mesh_terms: D000328:Adult; D001724:Birth Weight; D002823:Chorion / Q000473:pathology; D004200:Diseases in Twins; D005314:Embryonic and Fetal Development; D005260:Female; D005317:Fetal Growth Retardation / Q000209:etiology; D005865:Gestational Age; D006801:Humans; D016017:Odds Ratio; D010920:Placenta / Q000473:pathology; D011225:Pre-Eclampsia / Q000150:complications; D011247:Pregnancy; D014427:Twins; D014592:Uterine Hemorrhage / Q000150:complications