title: First trimester screening for other trisomies than trisomy 21, 18, and 13.
abstract: OBJECTIVE
  The objective of the study was to evaluate the performance of first trimester combined screening in cases of placental/fetal, mosaic or non-mosaic, autosomal trisomy other than trisomy 21, 18, or 13, and in cases of aneuploidy for a marker chromosome with focus on biochemical markers.
  
  
  METHODS
  We identified 66 cases in three large databases including 357 675 pregnancies from October 2003 to January 2014.
  
  
  RESULTS
  Seventy-seven percent of the 66 cases were screened positive at the combined first trimester screening (cFTS) for trisomy 21 or trisomy 18 or 13. The multiple of median (MoM) of Pregnancy Associated plasma protein A (PAPP-A) of the different aneuploidy groups ranged from 0.2 to 0.5 MoM, whereas the MoM of maternal serum free - β - human chorionic gonadotropin (FβhCG) was approximately 1.0 MoM. The exceptions being 0.2 MoM for cases involving chromosome 8 (n = 7) and 0.5 MoM for cases involving chromosome 9 (n = 3). The nuchal translucency MoM was approximately 1.0 MoM in all aneuploidy groups.
  
  
  CONCLUSIONS
  The cFTS program for trisomy 21, 18, and 13 is also sensitive to a broad range of rare chromosomal trisomies and chromosomal mosaicisms, primarily because of a strong detection capacity of PAPP-A MoM.
authors.affiliation: Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Tørring
authors.affiliation: Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Olav Bjørn
authors.initials: OB
authors.lastname: Petersen
authors.affiliation: Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Naja
authors.initials: N
authors.lastname: Becher
authors.affiliation: Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Ida
authors.initials: I
authors.lastname: Vogel
authors.affiliation: Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Uldbjerg
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D025063:Chromosome Disorders / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000378:metabolism; D002882:Chromosomes, Human, Pair 13 / Q000000981:diagnostic imaging / Q000378:metabolism; D002887:Chromosomes, Human, Pair 18 / Q000000981:diagnostic imaging / Q000378:metabolism; D002898:Chromosomes, Human, Pair 8 / Q000000981:diagnostic imaging / Q000378:metabolism; D002899:Chromosomes, Human, Pair 9 / Q000000981:diagnostic imaging / Q000378:metabolism; D016208:Databases, Factual; D004314:Down Syndrome / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D006801:Humans; D008875:Middle Aged; D009030:Mosaicism; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D011296:Prenatal Diagnosis; D014314:Trisomy / Q000175:diagnosis*; D000073839:Trisomy 13 Syndrome; D000073842:Trisomy 18 Syndrome; D055815:Young Adult
chemical_list: D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A; C579283:PAPPA protein, human