[Follow-up of fetuses with de novo copy number variations of unknown significance detected by chromosomal microarray analysis].

Objective: To analyze the prognosis of fetuses identified with de novo variants of unknown significance (VOUS) by chromosome microarray analysis (CMA).

Methods: A total of 6 826 fetuses who underwent prenatal CMA detection at the Prenatal Diagnosis Center of Drum Tower Hospital from July 2017 to December 2021 were selected as the study subjects. The results of prenatal diagnosis, and outcome of fetuses identified with VOUS of de novo origin were followed up.

Results: Among the 6 826 fetuses, 506 have carried VOUS, of which 237 were detected for the parent-of-origin and 24 were found to be de novo. Among the latters, 20 were followed up for 4 to 24 months. Four couples had opted elective abortion, 4 had developed clinical phenotypes after birth, and 12 were normal.

Conclusion: Fetuses with VOUS should be continuously follow-up, in particular those carrying de novo VOUS, in order to clarify their clinical significance.