Optimized criteria for using fluorescence in situ hybridization in the prenatal diagnosis of common aneuploidies.
OBJECTIVE
To evaluate the medical and economic performance of three strategies for selecting patients eligible for interphase FISH in the prenatal diagnosis of common aneuploidies.


METHODS
We evaluated three protocols on the same population that was referred for prenatal diagnosis between June 2001 and December 2006. The number of aneuploidies detected by FISH and the relative cost (reagent and technical staff cost) are reported for each strategy.


RESULTS
2707 women were referred for prenatal diagnosis either because of advanced maternal age over 38 (48%), abnormal maternal serum screening (35%) or prenatal ultrasound anomalies (17%). A total of 4.8% chromosomal anomalies (balanced and unbalanced) were diagnosed after karyotyping. Theoretically, interphase FISH should have detected 79.4% of the unbalanced anomalies. We observed a significant improvement in the trisomy 21 detection by selecting the probes according to the reason for referral. The last protocol adopted, which offers a rapid test to 57% of women undergoing amniocentesis, presents the best aneuploidy detection rate (68% of total aneuploidies, 87% of trisomy 21).


CONCLUSIONS
Selecting probes according to medical criteria patients combined with a technical procedure modification allows medico-economic improvement of interphase FISH in routine diagnosis.
Leclercq
Sandrine
S
Hopital Cochin-Saint Vincent de Paul, Unité de, Cytogénétique, France. sandrine.leclercq@cch.aphp.fr
Lebbar
Aziza
A
Grange
Gilles
G
Tsatsaris
Vassilis
V
Le Tessier
Dominique
D
Dupont
Jean-Michel
JM
D000328:Adult; D000649:Amniocentesis; D000782:Aneuploidy; D003661:Decision Support Techniques; D005260:Female; D005820:Genetic Testing / Q000191:economics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008423:Maternal Age; D011247:Pregnancy; D011248:Pregnancy Complications / Q000235:genetics; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies