title: Early transvaginal measurement of transcerebellar diameter in Down syndrome.
abstract: OBJECTIVE
  To evaluate the screening utility of early transvaginal measurement of the transverse cerebellar diameter for identification of Down syndrome fetuses.
  
  
  METHODS
  Measurements of the transverse cerebellar diameter were obtained by transvaginal sonography between 11 and 16 weeks of gestation in 544 fetuses with a normal karyotype and in 37 Down syndrome fetuses.
  
  
  RESULTS
  The transverse cerebellar diameter was found to show a fairly constant increment of values throughout the period evaluated with a linear relationship to the gestational age. The measurements obtained in Down syndrome fetuses are within the normal range for gestational age.
  
  
  CONCLUSIONS
  The transverse cerebellar diameter cannot be considered a useful tool in the detection of Down syndrome in early pregnancy.
authors.affiliation: Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Guariglia
authors.forename: P
authors.initials: P
authors.lastname: Rosati
mesh_terms: D002531:Cerebellum / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000196:embryology*; D004314:Down Syndrome / Q000000981:diagnostic imaging*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007621:Karyotyping; D008423:Maternal Age; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal; D014621:Vagina