Analyzing false-negative results detected in low-risk non-invasive prenatal screening cases

The non-invasive prenatal screening (NIPS) has been introduced into clinical practice with a high sensitivity and specificity. Although the false-negative

Our results revealed that mosaicism contributes to a major cause of false negative in NIPS, and highlighted the importance of ultrasound in identifying these false-negative results.

NIPS was performed using whole-genome massively parallel shotgun sequencing for screening common trisomies, rare autosomal aneuploidies, and subchromosome copy number variants. All the NIPS cases with a low-risk result performed in our center in 2017 were followed-up using medical records and telephone interview at 3 months after delivery. Fetal ultrasound

By following-up 10,975 low-risk results, we found 166 NIPS cases with adverse pregnancy outcomes, in which eight cases had diagnostic testing. Among them, four false-negative cases were confirmed, including one trisomy 18 caused by placental mosaicism, one mosaic tetrasomy 12p, and 2 microdeletion/microduplication cases.