Residual risk of noninvasive prenatal screening in pregnancies with ultrasound anomalies.

OBJECTIVES

To discuss the residual risk (RR) of noninvasive prenatal screening (NIPS) for the mothers with fetal ultrasound abnormalities.

METHODS

880 pregnant women with fetal ultrasound abnormalities accepted prenatal diagnosis by chromosomal microarray analysis (CMA) after amniocentesis. Furthermore, the detection efficiency of NIPS was evaluated and calculated based on our previous studies and other literatures. The RR of the chromosome abnormality results was then analyzed.

RESULTS

A total of 103 cases were confirmed as fetal chromosome abnormalities, including 65 (63.1%) of aneuploidies and 38 (36.9%) of clinical significant copy number variations (CNVs). Of which, based on the estimated NIPS efficacy, 87 cases could also be detected by NIPS. The detection rate (DR) was 84.5%, while 16 cases would be missed. The total of RR of NIPS in the fetuses with ultrasound anomalies was 2.0% (16/793), approximately one in 51. The top three RR of fetal ultrasound abnormalities were echogenic bowel (5.9%), multiple systems of structural anomalies (4.5%), and nervous system anomalies (4.2%).

CONCLUSION

The overall residual risk of NIPS in the fetuses with ultrasound anomalies was approximately 2.0%, especially in echogenic bowel, multiple systems of structural anomalies and nervous system anomalies.