Abstract:

Objective To investigate the relationship between different types of fetal congenital heartdisease（CHD）and chromosomal abnormalities，and to evaluate the value of low⁃depth CNV sequencing in fetalCHD，provide evidence to clinical consultation and assess fetal. Methods A total of 181 pregnant women whowere diagnosed as fetal CHD with or without extracardiac abnormalities by prenatal ultrasound in Liuzhou Maternaland Child Health care Hospital of Guangxi from January 2017 to May 2019. They were divided into two groupswhich one group included 146 pregnant women with independent cardiac malformation groups and another included35 cases with extracardiac abnormalities.we used karyotype analysis and CNV⁃seq analysis to statistically analyzethe chromosomal aberrations of CHD in different types of fetuses，and to follow up the pregnancy outcome andneonatal status of all cases. Results The anomaly detection rate was 11.0%（20/181）by karyotype analysis，and43 cases（43/181，23.8%）CNVs were detected by CNV⁃Seq，of which 28 cases（28/181，15.5%）were pathogenic；Compared with the traditional chromosome karyotype analysis，an additional 8.4% chromosome aberrations weredetected.It was statistically significant in CHD group with extracardiac abnormality compared with independentCHD group（40.0% vs. 9.6%，P < 0.05）. There were 117 live births（64.6%，117/181），62 pregnancy terminations，and 2 intrauterine still births. Conclusion CNV⁃seq improves the detection rate of CHD fetal chromosomal aberra⁃tion，is benefit to the evaluation of fetal prognosis in prenatal clinical consultation，provides more evidence forpregnant women to continue pregnancy，and contributes to the optimization of maternal and infant outcomes. It isalso an effective supplementary detection method for chromosome karyotype analysis，providing a more clinicallyapplicable detection technique for prenatal diagnosis of CHD fetus.

Key words: fetal congenital heart disease, prenatal diagnosis, low depth copy number variation sequencing, copy number variation, prognosis