Inability to detect cell free fetal DNA in the urine of normal pregnant women nor in those affected by preeclampsia associated HELLP syndrome.
OBJECTIVE
Recent reports have indicated that cell-free fetal DNA can be detected in the urine of pregnant women. We attempted to reproduce those data.


METHODS
Urine samples were collected from 18 normal pregnant women (11 with a male fetus). Urinary DNA was examined by Y-chromosome-specific nested polymerase chain reaction (PCR) or real-time PCR. Samples were also examined from two pregnancies complicated by HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome, which had very high levels of cell-free fetal DNA in the maternal plasma. To validate our data, a quantitative comparison of different DNA extraction procedures used in the previous reports was performed.


RESULTS
In no instance were we able to detect any fetal DNA in maternal urine, although copious quantities of cell-free fetal DNA were present in the maternal plasma of those pregnancies affected by HELLP syndrome. Our quantitative analysis of the various extraction procedures used indicated that the commercial column elution method we used was comparable, if not superior, to the noncommercial methods used in previous reports.


CONCLUSIONS
Our data strongly suggest that cell-free fetal DNA is not readily detectable in maternal urine, even under conditions known to increase kidney permeability.
Li
Ying
Y
Laboratory for Prenatal Medicine, University Women's Hospital/Department of Biomedical Research, University of Basel, Spitalstrasse 21, CH 4031 Basel, Switzerland.
Zhong
Xiao Yan
XY
Kang
Anjeung
A
Troeger
Carolyn
C
Holzgreve
Wolfgang
W
Hahn
Sinuhe
S
D041322:Chromosomes, Human, Y / Q000235:genetics; D004247:DNA / Q000652:urine*; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D017359:HELLP Syndrome / Q000235:genetics* / Q000652:urine; D006801:Humans; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction / Q000379:methods; D011225:Pre-Eclampsia / Q000209:etiology; D011247:Pregnancy; D012016:Reference Values; D051876:Sex-Determining Region Y Protein; D014157:Transcription Factors
D017931:DNA Primers; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D051876:Sex-Determining Region Y Protein; D014157:Transcription Factors; D004247:DNA