Study On The Relationship Between Fetal Ventriculomegaly And Chromosome Abnormality

Objective:Explore the correlation between fetal ventriculomegaly(VM)and chromosomal abnormalities.Methods: We collected 237 cases of fetuses with ventriculomegaly of singleton pregnancy in the outpatient clinic of Shengjing Hospital from January 2018 to April2020.According to different classification methods,the collected cases were divided into mild group(10-12mm),moderate group(13-15mm)and severe group(≥ 15mm),according to the degree of broadening of lateral ventricle.According to whether or not with other structural abnormalities,they were divided into isolated ventriculomegaly(IVM)(no other structural abnormalities except VM),non-isolated ventriculomegaly(NIVM)(with other structural abnormalities except VM),unilateral group and bilateral group according to laterality.The chromosome abnormalities of fetuses with VM in different groups were analyzed.For the collected cases,the samples were obtained by amniocentesis,and the chromosome abnormalities were detected by CNV-Seq.The results of chromosome copy number variation were analyzed by DECIPHER(Database of Genomic Variation and Phenotype in Humans using Ensembl Resources),DGV(Database of Genomic Variants),OMIM(Online Mendelian Inheritance in Man)database and so on.Through telephone follow-up to understand the development of children.Results: The overall detection rate of chromosomal abnormalities in fetuses with VM was 12.24%(29/237).The collected cases were classified and studied according to different classification methods.(1)Mild group,moderate group and severe group.The detection rates of pathogenic chromosomal abnormalities in the three groups were10.6%(15/ 142),12.7%(8/ 63)and 18.8%(6/ 32)respectively P= 0.440).(2)There were 179 cases of IVM and 58 cases of NIVM.The detection rate of pathogenic chromosomal abnormalities in the NIVM and IVM are 10.3(6 / 58),12.8%(23 /179)(P= 0.613).(3)There were 113 cases of bilateral VM and 124 cases of unilateral VM.The detection rate of pathogenic chromosomal abnormalities in the bilateral VM and unilateral VM are 13.3%(15/113),11.3%(14/124),(P=0.642).Telephone follow-up was successful in 106 cases,including mild group(n = 57),moderate group(n =28)and severe group(n = 21).The rates of chromosome abnormalities in induced fetuses were 90%(9/10),75%(2/3)and 40%(4/10),respectively.There were 3 cases whose development was obviously behind that of the same age infants.One case was non-isolated mild unilateral VM,one case was nonisolated moderate unilateral VM,and one case was isolated moderate bilateral VM.Conclusion:The risk of pathogenic chromosome abnormalities in fetuses with VM is increased.CNV-Seq detection has important clinical significance in prenatal diagnosis of fetuses with VM.For fetal VM,prenatal examination should be carried out closely during pregnancy,prenatal diagnosis should be carried out in time,and follow-up should be strengthened after delivery.