title: Prenatal diagnosis and obstetric outcomes in triplet pregnancies in relation to chorionicity.
abstract: OBJECTIVE
  This study describes the frequency, pregnancy complications and outcomes of non-trichorionic triplet pregnancies.
  
  
  METHODS
  A retrospective observational study.
  
  
  METHODS
  Two tertiary level referral centres of Obstetrics and Prenatal Medicine, Germany.
  
  
  METHODS
  All women booked to receive targeted ultrasound screening between January 1998 and June 2003. The mixed low and high risk population included 36,430 women with ultrasound examinations between 11 and 24 weeks of gestation. Of those with available outcome, 176 were triplet pregnancies with three viable fetuses.
  
  
  METHODS
  Analysis of ultrasound data and perinatal outcome in triplet gestations who had first and second trimester targeted ultrasound examination. Pregnancies with monochorionic or dichorionic placentation were identified and pregnancy outcome was compared to trichorionic triplets.
  
  
  METHODS
  Intrauterine fetal death, fetal growth restriction (FGR), mean discordance and survival rate in non-trichorionic versus trichorionic triplets.
  
  
  RESULTS
  Triplets were trichorionic in 81.8% and had a monochorionic or dichorionic placentation in the remaining 18.2%. The rate of monochorionicity and dichorionicity was significantly higher after spontaneous conception than after assisted reproductive technologies (44.8%vs 12.9%, P < 0.001). In non-reduced monochorionic and dichorionic triplets compared with non-reduced trichorionic triplets, there was a higher rate of intrauterine fetal death (8.8%vs 1.5%, P < 0.01), FGR (33.3%vs 25.5%), mean discordance (20.5%vs 12.7%, P < 0.01), discordance >30% (26.3%vs 2.9%, P < 0.01) and delivery <32 weeks of gestations (47.4%vs 32.2%). There was a lower survival rate in non-trichorionic triplets (84.2%) than in trichorionic ones (91.7%).
  
  
  CONCLUSIONS
  Triplet pregnancies with a monochorionic or dichorionic placentation are at significantly higher risk of adverse pregnancy outcome compared with trichorionic pregnancies. First trimester evaluation of chorionicity is strongly emphasised.
authors.affiliation: Department of Obstetrics and Prenatal Medicine, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany.
authors.forename: Annegret
authors.initials: A
authors.lastname: Geipel
authors.forename: Christoph
authors.initials: C
authors.lastname: Berg
authors.forename: Alexander
authors.initials: A
authors.lastname: Katalinic
authors.forename: Hanno
authors.initials: H
authors.lastname: Plath
authors.forename: Manfred
authors.initials: M
authors.lastname: Hansmann
authors.forename: Ute
authors.initials: U
authors.lastname: Germer
authors.forename: Ulrich
authors.initials: U
authors.lastname: Gembruch
mesh_terms: D002823:Chorion / Q000000981:diagnostic imaging*; D005260:Female; D005313:Fetal Death / Q000000981:diagnostic imaging / Q000209:etiology; D005317:Fetal Growth Retardation / Q000209:etiology / Q000648:ultrastructure; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D016019:Survival Analysis; D014310:Triplets; D016216:Ultrasonography, Prenatal / Q000379:methods*