First-trimester prenatal diagnosis performed on pregnant women with fetal ultrasound abnormalities: The reliability of interphase fluorescence in situ hybridization (FISH) on mesenchymal core for the main aneuploidies

Toutain, J.; Epiney, M.; Begorre, M.; Dessuant, H.; Vandenbossche, F.; Horovitz, J.; Saura, R.

doi:10.1016/j.ejogrb.2009.12.015

« Previous Next »European Journal of Obstetrics & Gynecology and Reproductive Biology
Volume 149, Issue 2 , Pages 143-146, April 2010

First-trimester prenatal diagnosis performed on pregnant women with fetal ultrasound abnormalities: The reliability of interphase fluorescence in situ hybridization (FISH) on mesenchymal core for the main aneuploidies

J. Toutain
- Fetal Medicine Center, University Hospitals, Bordeaux, France
- University Victor Segalen Bordeaux 2, Bordeaux, France
M. Epiney
- Fetal Medicine Center, University Hospitals, Bordeaux, France
M. Begorre
- Fetal Medicine Center, University Hospitals, Bordeaux, France
- University Victor Segalen Bordeaux 2, Bordeaux, France
H. Dessuant
- Department of Cytogenetics, Biomnis Laboratory, Paris, France
F. Vandenbossche
- Fetal Medicine Center, University Hospitals, Bordeaux, France
J. Horovitz
- Fetal Medicine Center, University Hospitals, Bordeaux, France
- University Victor Segalen Bordeaux 2, Bordeaux, France
R. Saura
- Fetal Medicine Center, University Hospitals, Bordeaux, France
- University Victor Segalen Bordeaux 2, Bordeaux, France
- Corresponding author at: Service de génétique médicale – Maternité Pellegrin, CHU de Bordeaux, Place Amélie Raba-Léon, 33076 Bordeaux cedex, France. Tel.: +33 5 56 79 55 58; fax: +33 5 56 79 48 15.

Received 17 August 2009; received in revised form 12 November 2009; accepted 11 December 2009. published online 28 December 2009.

Abstract

Objectives

To examine the reliability of interphase FISH analysis of the main aneuploidies performed on mesenchymal core when prenatal diagnosis was performed on pregnant women with first-trimester fetal abnormalities on ultrasound.

Study design

386 first-trimester prenatal examinations were investigated from chorionic villus samplings for increased nuchal translucencies or other fetal ultrasound abnormalities. Interphase fluorescence in situ hybridization (FISH) for the main aneuploidies (trisomies 13, 18, 21 and gonosomal aneuploidies) was performed on the mesenchymal core of villi. Molecular cytogenetic results were always complemented by conventional cytogenetic results on long-term cultured villi (LTC-villi). Short-term cultured villi (STC-villi) preparations were retrospectively performed only when a chromosomal abnormality was observed with interphase FISH and/or LTC-villi.

Results

88 chromosomal abnormalities (88/386=22.8% of first-trimester diagnoses) which could discuss subsequent abortions were observed after LTC-villi preparations. All cases possibly detectable by interphase FISH were detected. Thus, 85 aneuploidies (85/386=22.0% of first-trimester diagnoses; 85/88=96.6% of chromosomal abnormalities) were detected by interphase FISH, allowing early abortion by curettage before week 14 amenorrhea. No discrepancy occurred between interphase FISH and LTC-villi results for the aneuploidies studied. Three false-negative results (3/386=0.77% of first-trimester diagnoses; 3/88=3.41% of chromosomal abnormalities) were observed with STC-villi.

Conclusion

We observed a high rate of false-negative results on cytotrophoblast cells. Conversely, interphase FISH of the main aneuploidies on the mesenchymal core provided rapid and reliable results, and therefore should be preferred to STC-villi in first-trimester prenatal diagnosis performed on pregnant women with fetal abnormalities on ultrasound.

Keywords: Cytogenetics, Chorionic villus sampling, Mesenchymal core, Interphase fluorescence in situ hybridization, False-negative results