The Replacement of Cytogenetic Analysis by Direct Chorionic Villi Sampling Preparation with Quantitative Fluorescence PCR

AIM: The aim of this study is to assess the replacement of chromosomal analysis of chorionic villi (CV) direct preparation samples (DIR) by quantitative fluorescence PCR (QF-PCR) and to determine its advantages in routine prenatal diagnosis. METHODS: From a total of 4,020 CV samples, rapid results were obtained either by conventional cytogenetic analysis of DIR in 2,770 samples, or by QF-PCR analysis in 1,250 samples. The final results were given after long-term culture (LTC). RESULTS: The frequencies of unbalanced fetal karyotypes were not significantly different, being 4.8% by DIR-LTC and 4.3% by QF-PCR-LTC. No false-negative or false-positive results were obtained from either approach. CONCLUSION: QF-PCR can replace chromosomal analysis of CV-DIR in most cases during routine prenatal diagnosis, requiring smaller CV samples and being more labor effective. Coupled with LTC, it is a robust diagnostic approach with high predictive value for the most frequent fetal trisomies.