title: Triploidy in a twin pregnancy: small placenta volume as an early sonographical marker.
abstract: BACKGROUND
  We report a case of a twin pregnancy with triploidy of maternal phenotype of one foetus and no chromosomal anomaly of the other twin and the role of sonographical placental volumetry.
  
  
  METHODS
  At 12 weeks of gestation, a dichorionic twin pregnancy discordant in growth is diagnosed. 3D ultrasound reveals a distinctly small placental volume of foetus II. Amniocentesis at 16 weeks discloses triploidy of this foetus. Sonography reveals asymmetrical foetal growth retardation, a severe heart defect and bilateral cleft lip and palate, typical findings in triploidy. Selective feticide at week 20+3 is followed by pre-term birth of foetus I at 27 weeks.
  
  
  CONCLUSIONS
  Small placental volume in addition to growth restriction of one foetus early in the course of a twin pregnancy could be an important early marker influencing the decision for chorionic villous sampling at 12 weeks instead of amniocentesis at 16 weeks and it could lead to an earlier selective pregnancy termination of a triploid twin. This would lower the risk of pre-term birth and enable a better outcome for the remaining healthy foetus.
authors.affiliation: Ludwig-Boltzmann-Institute for Clinical Obstetrics and Gynaecology, Department of Obstetrics and Gynaecology, Donauspital Vienna, Austria. rainer_gassner@bigfoot.com
authors.forename: Rainer
authors.initials: R
authors.lastname: Gassner
authors.forename: Martin
authors.initials: M
authors.lastname: Metzenbauer
authors.forename: Erich
authors.initials: E
authors.lastname: Hafner
authors.forename: Ursula
authors.initials: U
authors.lastname: Vallazza
authors.forename: Karl
authors.initials: K
authors.lastname: Philipp
mesh_terms: D000015:Abnormalities, Multiple / Q000000981:diagnostic imaging / Q000235:genetics; D000025:Abortion, Eugenic; D000328:Adult; D000649:Amniocentesis; D015415:Biomarkers; D004200:Diseases in Twins / Q000175:diagnosis / Q000235:genetics*; D005260:Female; D006801:Humans; D010641:Phenotype; D010920:Placenta / Q000002:abnormalities / Q000000981:diagnostic imaging*; D011123:Polyploidy; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D014429:Twins, Dizygotic / Q000235:genetics*; D016216:Ultrasonography, Prenatal
chemical_list: D015415:Biomarkers