Validity of chromosomal aneuploidies testing during pregnancy: A comparison of karyotype, interphase-FISH and QF-PCR techniques

Prenatal diagnosis of chromosomal abnormalities is an important challenge for pregnancy management has relied on conventional cytogenetic analysis of cultured amniotic fluid, chorionic villi, or fetal blood for a long time. New molecular methods included FISH and QF-PCR on uncultured amniotic fluid or chorionic villi have been applied recently for the rapid aneuploidies detection in chromosomes 13, 18, 21, X and Y. Both molecular methods are quicker than Karyotype as conventional cytogenetic technique. The advantages of QF-PCR include detection of trisomy, mosaicism and maternal cell contamination. This technique is more cost effective, less labor-intensive and more suitable for large sample numbers in comparison to FISH. FISH is a robust method and extensively validated. It detects mosaicism and trisomy. Herein we aimed to assess prenatal diagnosis of aneuploidies in chromosomes 13, 18, 21, X and Y. For this aim, amniotic fluid samples have collected for analysis of common chromosomal aneuploidies using Karyotype, FISH and QF-PCR methods. 69 samples have obtained by amniocentesis from 15th-18th week of pregnancies and subjected for comparative analysis by three techniques: FISH, QF, and Karyotype with the same accuracy concerning the detection of trisomy 13, 18, 21, and sex chromosomes X and Y. We conclude that molecular techniques are rapid-reliable methods for analysis of chromosome number in uncultured amniotic fluid. Nevertheless, QF-PCR and FISH are an alternative option, if timing is a limiting factor. This report in line with previous studies emphasizes the importance of molecular techniques for the prenatal identification of the numerical chromosomal abnormalities and ultimately management of pregnancies saving patients from anxiety.