title: The risk of a major trisomy in fetuses with pyelectasis: the impact of an abnormal maternal serum screen or additional sonographic markers.
abstract: OBJECTIVE
  This study was undertaken to evaluate the contribution of either an abnormal second-trimester maternal serum screen or the presence of additional sonographic markers of aneuploidy to the risk of a major trisomy (13, 18, and 21) in fetuses with pyelectasis.
  
  
  METHODS
  A retrospective review of a large amniocentesis database was performed. Specimens obtained after the sonographic detection of fetal pyelectasis were eligible for analysis. Age-matched women who underwent amniocentesis solely for maternal anxiety or advanced maternal age served as controls.
  
  
  RESULTS
  760,495 amniocentesis specimens were analyzed. Fetal pyelectasis was detected in 671 cases. Pyelectasis, with either a single or multiple additional sonographic markers, was associated with an 8-fold and 62-fold increase in the prevalence of major trisomies (odds ratio = 7.7, 95% CI = 1.2-32.6, P = 0.02) and (odds ratio = 61.9, 95% CI = 13.2-144.6, P < .001), respectively. Pyelectasis with an abnormal maternal serum screen, with or without additional sonographic markers, was associated with a 32-fold and a 205-fold increase in major trisomies (odds ratio = 32.2, 95% CI = 5.3-94.8, P < .001) and (odds ratio = 205.8, 95% CI = 37.9-427.6, P < .001), respectively.
  
  
  CONCLUSIONS
  In fetuses with pyelectasis, the presence of additional sonographic markers or an abnormal maternal serum screen significantly increases the risk of trisomy 13, 18, and 21.
authors.affiliation: Department of Obstetrics and Gynecology, Lenox-Hill Hospital, New York, NY, USA.
authors.forename: Eran
authors.initials: E
authors.lastname: Bornstein
authors.forename: Yoni
authors.initials: Y
authors.lastname: Barnhard
authors.forename: Alan E
authors.initials: AE
authors.lastname: Donnenfeld
authors.forename: Asaf
authors.initials: A
authors.lastname: Ferber
authors.forename: Michael Y
authors.initials: MY
authors.lastname: Divon
mesh_terms: D000328:Adult; D000649:Amniocentesis; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D025063:Chromosome Disorders / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging; D005260:Female; D005315:Fetal Diseases / Q000097:blood / Q000000981:diagnostic imaging; D006801:Humans; D006869:Hydronephrosis / Q000097:blood / Q000150:complications / Q000000981:diagnostic imaging*; D011247:Pregnancy; D012189:Retrospective Studies; D012306:Risk; D014314:Trisomy / Q000175:diagnosis*; D016216:Ultrasonography, Prenatal
chemical_list: D015415:Biomarkers