title: The frontal space measurement in euploid and aneuploid pregnancies at 11-13 weeks' gestation.
abstract: OBJECTIVE
  The aim of this study is to evaluate whether the measurement of the frontal space (FS) improves first trimester combined aneuploidy screening.
  
  
  METHODS
  We have presented a retrospective study including 2D images of the nuchal translucency measurement of 300 euploid and 133 trisomic fetuses that were seen at the prenatal department at the University of Tuebingen, Germany. For the FS measurement, a mandibulo-maxillary line (MML) was created by connecting the anterior edge of the mental protuberance and anterior edge of the maxilla. The MML was then extended upwards. A measurement was taken perpendicular from the MML to the skin line over the point of largest excursion of the fetal forehead. After transformation into z-scores based on the crown rump length, the FS distribution in fetuses with trisomy 21, 18, and 13 was compared with the euploid group by using a student's t-test.
  
  
  RESULTS
  The mean FS in euploid fetuses was 1.25 mm. In fetuses with trisomy 21, 18, and 13, the mean FS measurements were 2.96, 3.22, and 2.03 mm. In euploid and trisomy 21, 18, and 13 pregnancies, FS measurements were above the 95th centile in 5.3%, 41.1%, 34.3%, and 12.5% of the cases. The mean z-scores were significantly higher in trisomy 21 and 18.
  
  
  CONCLUSIONS
  First trimester FS measurement may improve first trimester combined screening.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Tuebingen, Tuebingen, Germany.
authors.forename: Britta
authors.initials: B
authors.lastname: Yazdi
authors.forename: Peter
authors.initials: P
authors.lastname: Riefler
authors.forename: Kristina
authors.initials: K
authors.lastname: Fischmüller
authors.forename: Jiri
authors.initials: J
authors.lastname: Sonek
authors.forename: Markus
authors.initials: M
authors.lastname: Hoopmann
authors.forename: Karl Oliver
authors.initials: KO
authors.lastname: Kagan
mesh_terms: D000328:Adult; D000782:Aneuploidy; D015415:Biomarkers; D025063:Chromosome Disorders / Q000175:diagnosis; D002882:Chromosomes, Human, Pair 13; D002887:Chromosomes, Human, Pair 18; D004247:DNA / Q000032:analysis; D004314:Down Syndrome / Q000175:diagnosis; D005260:Female; D005546:Forehead / Q000196:embryology*; D005865:Gestational Age; D006801:Humans; D059785:Karyotype; D008334:Mandible; D008423:Maternal Age; D008437:Maxilla; D048208:Nuchal Translucency Measurement; D015588:Observer Variation; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D014314:Trisomy / Q000175:diagnosis; D000073839:Trisomy 13 Syndrome; D000073842:Trisomy 18 Syndrome
chemical_list: D015415:Biomarkers; D004247:DNA