Influence of copy number variation of unknown significance on the pregnancy outcomes.

To investigate the influence of VUS on pregnancy outcome and fetuses. 132 VUS CNVs were identified in 3657 fetal amniotic fluid specimens by CNV-Seq. Parent-of-origin testing was subsequently analyzed to determine whether the CNV was inherited or de novo. Pregnancy outcomes of the pregnant women were tracked, and clinical assessments were performed to determine the evidence of any disease in the newborns between 1 and 2 years of age. Pregnant women with VUS in their fetuses were more likely to choose to continue with the pregnancy (105 out of 118, 88.98%). However, only a small number (2 out of 14, 14.29%) of pregnant women with de novo VUS chose to terminate the pregnancies. Additionally, out of the 115 live births, 3 fetuses carrying VUS were born with abnormalities, that could not be definitively linked to VUS. The majority of CNVs classified as VUS are likely to have non-disease outcomes in the fetuses. Therefore, it is important to establish a VUS fetal database, adopt dynamic tracking and follow-up. This will provide more powerful clinical evidence, based on the results of fetal ultrasound and the source of VUS; which will ultimately facilitate better clinical pregnancy management decisions and reduce anxiety for pregnant women.