Background
To investigate the detectability of non-invasive prenatal testing (NIPT) after prenatal screening to detect foetal chromosomal abnormalities in pregnant women at high risk, and the number of foetal abnormalities could be missed by NIPT.
Conclusions
NIPT could miss 30.0% of the chromosomal abnormalities detected by amniocentesis and cytogenetic testing. This proportion will likely decrease in the future due to further development of NIPT.
Methods
From January 2009 to March 2018, 3,099 pregnant women at high risk for trisomy 21 and 18 according to the
Results
In all, 177 (5.7%, 177/3,099) chromosomal abnormalities were identified. These included 129 (72.9%) abnormal numbers of chromosomes, 6 (3.4%) chromosome structural abnormalities, and 42 (23.7%) other abnormalities, including copy number variation, inversions, and chromosome additions/deletions. Of the 177 (70.0%) chromosomal abnormalities, 124 were detected and 53 were missed by NIPT. Conclusions: NIPT could miss 30.0% of the chromosomal abnormalities detected by amniocentesis and cytogenetic testing. This proportion will likely decrease in the future due to further development of NIPT.