Prenatal diagnosis from fetal urine in bladder outlet obstruction: success rates for traditional cytogenetic evaluation and interphase fluorescence in situ hybridization.
OBJECTIVE
To determine the optimal approach to the prenatal chromosome analysis of fetal urine from fetuses with bladder outlet obstruction.


METHODS
Retrospective evaluation of traditional cytogenetic and interphase fluorescence in situ hybridization (FISH) analysis on fetal urine specimens from fetuses with bladder outlet obstruction.


RESULTS
Traditional cytogenetic analysis was successful on 71 (95%) of 75 samples, and FISH was informative on 20 (65%) of 31 specimens. The combination of traditional cytogenetic analysis and FISH yielded a 96% diagnostic success rate. The mean turnaround time was 8 days (range 5-14) for traditional cytogenetic analysis and 1.6 days (range 1.0-4.0) for FISH. Chromosome abnormalities were detected in 6 (7.9%) of 76 pregnancies.


CONCLUSIONS
Traditional cytogenetic analysis achieves a high success rate (95%) and is superior to FISH for chromosome evaluation of fetal urine. However, FISH, when informative, can complement traditional cytogenetics as it will expeditiously rule out common trisomies in fetuses with bladder outlet obstruction.
Donnenfeld
Alan E
AE
Genzyme Genetics, Philadelphia, Pennsylvania, USA.
Lockwood
David
D
Custer
Trace
T
Lamb
Allen N
AN
D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007621:Karyotyping / Q000379:methods*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D001748:Urinary Bladder Neck Obstruction / Q000151:congenital / Q000175:diagnosis; D014556:Urine / Q000166:cytology*