title: Monochorionic diamniotic infants without twin-to-twin transfusion syndrome.
abstract: BACKGROUND
  Monochorionic-diamniotic twins (MoDi) occur in 0.3% of all pregnancies. Twin-to-twin transfusion syndrome (TTS) that occurs in 20% of MoDi pregnancies is associated with high perinatal morbidity and mortality. MoDi twins without TTS are more frequent (80%) but have been scarcely reported.
  
  
  OBJECTIVE
  To study perinatal morbidity and mortality of 74 MoDi twin sets without TTS and to compare it to that of 38 sets of MoDi twins with TTS.
  
  
  METHODS
  Chorionicity was determined by gender and placental examination. Gestational age (GA) was set by sonography and pediatric examination. TTS was diagnosed clinically and by sonography, discordance was defined by twins birth weight difference > or =20%, and fetal growth restriction was determined by using a twin-specific nomogram.
  
  
  RESULTS
  MoDi twin pregnancies without and with TTS were similar in demographics, live births, history of preeclampsia, fetal distress and cesarean delivery. They were different (p<0.01) in discordant pregnancies (36 and 79%), GA at delivery (32 and 29 weeks) intrauterine growth restriction (39 and 89%) and neonatal mortality (12 and 36%). Concordant (47 sets) and discordant (27 sets) MoDi twins without TTS were clinically similar.
  
  
  CONCLUSIONS
  MoDi twins without TTS have high rates of birth weight discordance, fetal growth restriction, fetal distress, prematurity and cesarean delivery. Although their perinatal mortality is low, the reported occurrence and the short- and long-term impacts of fetal and neonatal morbidities warrants attention.
authors.affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics and Obstetrics, College of Medicine and Public Health, The Ohio State University, Columbus, OH 43210-1228, USA.
authors.forename: Leandro
authors.initials: L
authors.lastname: Cordero
authors.forename: Albert
authors.initials: A
authors.lastname: Franco
authors.forename: Saju D
authors.initials: SD
authors.lastname: Joy
authors.forename: Richard W
authors.initials: RW
authors.lastname: O'shaughnessy
mesh_terms: D000650:Amnion / Q000000981:diagnostic imaging* / Q000473:pathology; D002423:Cause of Death; D002823:Chorion / Q000000981:diagnostic imaging* / Q000473:pathology; D004200:Diseases in Twins / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D005260:Female; D005316:Fetal Distress / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D005330:Fetofetal Transfusion / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D008297:Male; D010920:Placenta / Q000000981:diagnostic imaging / Q000473:pathology; D011247:Pregnancy; D012306:Risk; D016019:Survival Analysis; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D016216:Ultrasonography, Prenatal