Same-day prenatal diagnosis of common chromosomal aneuploidies using microfluidics-fluorescence in situ hybridization

Abstract

Rapid molecular prenatal diagnostic methods, such as fluorescence in situ hybridization (FISH), quantitative fluorescence-PCR, and multiplex ligation-dependent probe amplification, can detect common fetal aneuploidies within 24 to 48 h. However, specific diagnosis or aneuploidy exclusion should be ideally available within the same day as fetal sampling to alleviate parental anxiety. Microfluidic technologies integrate different steps into a microchip, saving time and costs. We have developed a cost-effective, same-day prenatal diagnostic FISH assay using microfluidics. Amniotic fluids (1-4 mL from 40 pregnant women at 15-22 weeks of gestation) were fixed with Carnoy's before loading into the microchannels of a microfluidic FISH-integrated nanostructured device. The glass slides were coated with nanostructured titanium dioxide to facilitate cell adhesion. Pretreatment and hybridization were performed within the microchannels. Fifty nuclei were counted by two independent analysts, and all results were validated with their respective karyotypes. Of the 40 samples, we found three cases of fetal aneuploidies (trisomies 13, 18, and 21), whereas the remaining 37 cases were normal. Results were concordant with their karyotypes and ready to be released within 3 h of sample receipt. Microfluidic FISH, using 20-fold less than the recommended amount of probe, is a cost-effective method to diagnose common fetal aneuploidies within the same day of fetal sampling.