Chromosomal microarray analysis in prenatal diagnosis of women with isolated adverse pregnancy history / 中华围产医学杂志

ABSTRACT

Objective:To investigate the abnormal results of chromosomal microarray analysis (CMA) in the subsequent pregnancy of women with adverse pregnancy history, and explore the applicability of CMA in women with different genetic etiology.Methods:Out of 5 563 pregnant women who received CMA test in Nanjing Drum Tower Hospital during June 2014 and July 2020, 169 cases that underwent prenatal diagnosis due to isolated adverse pregnancy history were retrospectively collected in this study. All the participants were divided into three groups based on the etiology type of probands, genetic origin and expected CMA outcome: high-risk group ( n=19, including 11 cases with inherited pathogenic copy number variations and eight cases with inherited chromosomal abnormalities), low-risk group ( n=113, including six cases with negative whole exome sequencing and/or CMA findings, 31 cases with confirmed monogenic disease, 47 cases with de novo pathogenic copy number variations and 29 cases with de novo chromosomal abnormalities), and unknown risk group ( n=40, none of the cases underwent genetic testing). Descriptive statistical analysis was used to summarize the abnormal detection of each group. Results:There were 169 mothers with 172 fetuses finally enrolled, including two twins and one woman with two singleton pregnancies. A total of nine cases of abnormal fetuses were detected by CMA, accounting for 5.2% (9/172). Among them, eight were in the high-risk group, which were all caused by parental abnormalities, and one case in the low-risk group was detected with a de novo 22q11.22q11.23 microduplication, which was arr[GRCh37]22q11.22q11.23(22,997,928-25,002,659)×3. No abnormality was detected in the 40 patients of unknown risk group. Conclusions:Clarifying the etiology of isolated adverse pregnancy history is crucial to the rational application of CMA. Monogenic disease, unknown cause or negative finding of CMA in probands may not be an indication for prenatal diagnosis of CMA.