title: Metabolic scaling and twin placentas.
abstract: OBJECTIVE
  Do monochorionic (MC) and/or dichorionic (DC) twins show allometric scaling between placental and birth weight (PW, BW)?
  
  
  METHODS
  We extracted BW, PW, gestational age (GA) and cord insertion type from 52 MC to 310 DC twins to calculate β. DC twins were analyzed as summed and as individuals if placentas were separate.
  
  
  RESULTS
  Mean β for MC (0.78 ± 0.02), DC summed (0.78 ± 0.02), and DC with separate placentas (0.77 ± 0.03 and 0.76 ± 0.04) all non-significant. GA, summed BWs, total PW, BW discordance, and cord insertion sites did not differ between twin types or with β.
  
  
  CONCLUSIONS
  MC and DC twins show allometric scaling similar to singletons.
authors.affiliation: Obstetrics and Gynecology, NewYork Methodist Hospital, Brooklyn, NY, USA. Electronic address: carolyn.salafia@gmail.com.
authors.forename: C M
authors.initials: CM
authors.lastname: Salafia
authors.affiliation: Obstetrics and Gynecology, NewYork Methodist Hospital, Brooklyn, NY, USA.
authors.forename: N
authors.initials: N
authors.lastname: Kiryankova
authors.affiliation: Pediatrics, NewYork Methodist Hospital, Brooklyn, NY, USA.
authors.forename: H
authors.initials: H
authors.lastname: Inany
authors.affiliation: Pediatrics, NewYork Methodist Hospital, Brooklyn, NY, USA.
authors.forename: P
authors.initials: P
authors.lastname: Charlagorla
authors.affiliation: Obstetrics and Gynecology, NewYork Methodist Hospital, Brooklyn, NY, USA.
authors.forename: M
authors.initials: M
authors.lastname: Park
authors.affiliation: Pediatrics, NewYork Methodist Hospital, Brooklyn, NY, USA.
authors.forename: N
authors.initials: N
authors.lastname: Khawar
authors.affiliation: Obstetrics and Gynecology, NewYork Methodist Hospital, Brooklyn, NY, USA; Pediatrics, NewYork Methodist Hospital, Brooklyn, NY, USA.
authors.forename: S
authors.initials: S
authors.lastname: VanHorn
authors.affiliation: Pediatrics, NewYork Methodist Hospital, Brooklyn, NY, USA.
authors.forename: B
authors.initials: B
authors.lastname: Dygulska
authors.affiliation: Pediatrics, NewYork Methodist Hospital, Brooklyn, NY, USA.
authors.forename: P
authors.initials: P
authors.lastname: Narula
authors.affiliation: Obstetrics and Gynecology, NewYork Methodist Hospital, Brooklyn, NY, USA.
authors.forename: S
authors.initials: S
authors.lastname: Lederman
mesh_terms: D001724:Birth Weight / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D005317:Fetal Growth Retardation / Q000378:metabolism / Q000473:pathology; D020567:Fetal Weight / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn; D009929:Organ Size; D010920:Placenta / Q000033:anatomy & histology* / Q000378:metabolism / Q000473:pathology; D011247:Pregnancy; D059285:Pregnancy, Twin / Q000378:metabolism*; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
keywords: Allometric scaling; Birth weight; Dichorionic; Monochorionic; Placental weight; Twins