title: Reliability of second trimester triple screening for Down syndrome in rhesus-negative women.
abstract: OBJECTIVE
  To find out whether there is considerable influence on second trimester serum concentrations owing to the rhesus status.
  
  
  METHODS
  This retrospective cohort study was performed at the Perinatology Unit of the GATA Haydarpasa Teaching Hospital. During the study interval, 2265 pregnancies met inclusion criteria. The blood samples were collected in 117 pregnancies with a maternal rhesus-negative blood group status. The control group consisted of 2148 pregnancies with a maternal rhesus-positive blood group status. Statistical analysis was performed by SPSS 11.0 statistical software.
  
  
  RESULTS
  Pregnancies with a maternal rhesus-negative blood group status were identified in 117 patients. The overall prevalence of pregnancies with a maternal rhesus-negative blood group status were 5.1% in our study. Only unconjugated estriol multiples of the median values were significantly decreased in rhesus-negative women (P<0.001). Alpha-fetoprotein and human chorionic gonadotrophin multiples of the median values did not differ significantly (P>0.05).
  
  
  CONCLUSIONS
  We conclude that if second trimester screening test to be used in Rh negative pregnancies, either the corrected value should be referred or double test result should be considered ignoring the unconjugated estriol result. Another option is the first trimester Down syndrome screening test.
authors.affiliation: Unit of Perinatology, GATA Haydarpasa Teaching Hospital, Uskudar, Istanbul, Turkey. muratmuhcu@yahoo.com
authors.forename: M
authors.initials: M
authors.lastname: Muhcu
authors.forename: E
authors.initials: E
authors.lastname: Mungen
authors.forename: O
authors.initials: O
authors.lastname: Dundar
authors.forename: S
authors.initials: S
authors.lastname: Bodur
authors.forename: L
authors.initials: L
authors.lastname: Tutuncu
authors.forename: V
authors.initials: V
authors.lastname: Atay
authors.forename: O
authors.initials: O
authors.lastname: Ozcan
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Yergok
mesh_terms: D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood; D004314:Down Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control; D004964:Estriol / Q000097:blood; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008403:Mass Screening; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012016:Reference Values; D012203:Rh Isoimmunization / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D014421:Turkey; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins; D004964:Estriol