Common chromosomal aneuploidy testing using non-invasive trophoblast retrieval and isolation from the cervix (TRIC) in pregnant women.

Purpose: Non-invasive prenatal diagnosis (NIPD) for aneuploidy has been developed to overcome the limitations of non-invasive prenatal testing (NIPT). NIPT, which analyzes cell-free fetal DNA (cffDNA) in the maternal blood, can only detect a few aneuploidies, such as trisomies 13, 18, and 21. Trophoblast retrieval and isolation from the cervix (TRIC) is an alternative method that separates trophoblasts from endocervical cells using a Papanicolaou smear for NIPD. Here, we report the application of fetal cells obtained from the uterine cervix using a non-invasive cervical cytobrush during the first trimester of pregnancy for diagnosing trisomies 13, 18, and 21, and sex chromosome anomalies.

Methods: Trophoblast cells were isolated from the cervical fluid samples of nine pregnant women diagnosed with aneuploidy between the 5th and 20th weeks of gestation using magnetic nanoparticles with a human leukocyte antigen-G antibody.

Results: Fluorescence in situ hybridization analysis of the isolated trophoblast cells identified aneuploidies in all nine samples, which was consistent with conventional prenatal genetic testing. The proportion of trisomic cells was between 14.35 and 23.8%, indicating that the isolated cells comprised some maternal cells.

Conclusions: In summary, we successfully identified aneuploidies using TRIC, suggesting its potential as a non-invasive prenatal genetic testing method. However, the efficiency of recovering trophoblast cells from TRIC remains to be elucidated.