title: Maternal urine for prenatal diagnosis--an analysis of cell-free fetal DNA in maternal urine and plasma in the third trimester.
abstract: OBJECTIVE
  The aim of the study was the detection, quantification and correlation of cell-free fetal (cff) DNA in maternal urine and plasma in normal and complicated pregnancies during the third trimester.
  
  
  METHODS
  One hundred and fifty-one urine and plasma samples obtained from 96 women carrying male fetuses, and 55 carrying female fetuses were collected and analyzed for cff-DNA using fluorescent PCR and quantitative real-time PCR. DNA was extracted from 1 mL maternal urine and analyzed with two different primer sets (SRY and DYS-14). The concentrations of cff and total DNA in maternal plasma were correlated with maternal and obstetric parameters using appropriate correlation analyses.
  
  
  RESULTS
  Y-chromosome-specific sequences were detected in 31 of 96 (32.3%) urine samples collected from women pregnant with male fetuses using DYS-14 and in 6 of 96 (6.3%) urine samples using SRY as primers using real-time PCR. All 96 plasma samples obtained from women carrying male fetuses were positive for cff-DNA using real-time PCR. Cff-DNA exhibited a correlation with gestational age (R = 0.244; P = 0.018) and an inverse correlation with the latency between blood collection and birth (R = - 0.218; P = 0.036). Total DNA showed a correlation with placental weight (R = 0.182; P = 0.034) and pregnancy-associated complications (R = 0.280; P < 0.001).
  
  
  CONCLUSIONS
  Our data confirm that cff-DNA is cleared by the kidneys in detectable amounts, but due to its low concentration or problematic detection in maternal urine this source seems inappropriate for noninvasive prenatal diagnosis.
authors.affiliation: Department of Obstetrics and Gynaecology, Medical University Graz, Auenbruggerplatz 14, A-8036 Graz, Austria.
authors.forename: Sandra
authors.initials: S
authors.lastname: Majer
authors.forename: Margit
authors.initials: M
authors.lastname: Bauer
authors.forename: Eva
authors.initials: E
authors.lastname: Magnet
authors.forename: Andrea
authors.initials: A
authors.lastname: Strele
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Giegerl
authors.forename: Martina
authors.initials: M
authors.lastname: Eder
authors.forename: Uwe
authors.initials: U
authors.lastname: Lang
authors.forename: Barbara
authors.initials: B
authors.lastname: Pertl
mesh_terms: D000782:Aneuploidy; D015415:Biomarkers / Q000097:blood; D041322:Chromosomes, Human, Y / Q000235:genetics*; D004247:DNA / Q000652:urine*; D005260:Female; D005333:Fetus; D006801:Humans; D008297:Male; D008431:Maternal-Fetal Exchange / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011296:Prenatal Diagnosis / Q000379:methods*; D020080:Tandem Repeat Sequences; D016482:Urinalysis / Q000379:methods*
chemical_list: D015415:Biomarkers; D004247:DNA