title: Anomalies of the placenta and umbilical cord in twin gestations.
abstract: The frequency of twin gestations has increased over the last few decades, mainly due to maternal age at childbearing, and the use of assisted reproductive technologies. Twins are at higher risk of aneuploidy, structural anomalies, and placental abnormalities. Some of the placental and umbilical cord abnormalities found in twin gestations are nonspecific and can be found in singleton gestations (ie, placenta previa, placental abruption, single umbilical artery, velamentous cord insertion, vasa previa, etc). However, other anomalies are unique to twin gestations, and are mainly associated with monochorionic twins-these include intraplacental anastomosis and cord entanglement. Most of these conditions can be diagnosed with ultrasound. An accurate and early diagnosis is important in the management of twin gestations. Determination of chorionicity, amnionicity, and the identification of placental anomalies are key issues for the adequate management of twin pregnancies. Pathologic placental examination after delivery can help in assessing the presence of placental and umbilical cord abnormalities, as well as providing information about chorionicity and gaining insight into the potential mechanisms of disease affecting twin gestations.
authors.affiliation: Department of Obstetrics, Saint Luc University Hospital, Université de Louvain, Brussels, Belgium. Electronic address: corinne.hubinont@uclouvain.be.
authors.forename: Corinne
authors.initials: C
authors.lastname: Hubinont
authors.affiliation: Department of Obstetrics, University Hospitals, Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Lewi
authors.affiliation: Department of Obstetrics, Saint Luc University Hospital, Université de Louvain, Brussels, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bernard
authors.affiliation: Department of Pathology, Saint Luc University Hospital, Université de Louvain, Brussels, Belgium.
authors.forename: Etienne
authors.initials: E
authors.lastname: Marbaix
authors.affiliation: Department of Obstetrics, Saint Luc University Hospital, Université de Louvain, Brussels, Belgium.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Debiève
authors.affiliation: Institute for Women's Health, University College London Medical School, London, United Kingdom.
authors.forename: Eric
authors.initials: E
authors.lastname: Jauniaux
mesh_terms: D002823:Chorion; D005260:Female; D047109:Fetal Development; D006801:Humans; D006828:Hydatidiform Mole / Q000000981:diagnostic imaging; D010920:Placenta / Q000002:abnormalities* / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000473:pathology; D010922:Placenta Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology; D011247:Pregnancy; D059285:Pregnancy, Twin / Q000706:statistics & numerical data; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D016216:Ultrasonography, Prenatal; D014470:Umbilical Cord / Q000002:abnormalities* / Q000000981:diagnostic imaging; D016157:Vascular Fistula / Q000000981:diagnostic imaging / Q000453:epidemiology
keywords: chorionicity; cord entanglement; discordant growth; fetal placental ratio; intertwin septum; multiple gestation; twin to twin transfusion syndrome; vascular anatomosis; zygosity