Genetic Characteristic And Prognosis Of The Fetuses With Aortic Arch Abnormalities

Objective:To explore the genetics charecteristics and prognosis among fetuses with aortic arch abnormalities(AAA)and to provide evidence-based genetic counseling and clinical decision for these fetuses.Methods:This was a cross-sectional study.A range of data were recorded for each patient between January 2014 and June 2021,including age of pregnancies,fetal echocardiograms,screening ultrasound,genetic results,pregnancy outcomes and neonatal prognosis.Excel software was used to recorded these data.Results:1.A total of 243 cases of AAA were included.The average age of pregnancies was 28.54 years old(range 18 to 42 years old).Among them,24 pregnancies had advanced maternal age(≥35 years old),accounting for 9.9%.2.Classification of AAA:There were 151 cases(62.1%)of aberrant right subclavian artery(ARSA).80 cases of right aortic arch(RAA).Out of them,49 cases(20.2%)combined with left subclavian artery(RAA-ALSA),31 cases(12.8%)combined with mirror-image branching(RAMI).Twelve cases(4.9%)of double aortic arch(DAA).RAMI was often associated with other cardiac malformations,especially the conotruncal defects.3.Amniocentesis was performed in 82 fetuses.Karyotype analysis results were available for all 82 cases.and chromosome microarray analysis(CMA)results were available for 53(out of 82)cases.In total,chromosomal abnormalities were detected in 4.0%(6/56)of fetuses with ARSA,4.4%(2/45)and 36.4%(4/11)for isolated and non-isolated ARSA,respectively.There was a significant difference between the two groups in terms of frequency(P=0.011).Similarly,chromosomal abnormalities was detected in 21.7%(5/23)of fetuses with RAA(including RAA-ALSA and RAMI),18.8%(3/16)and 28.6%(2/7)in isolated RAA and in non-isolated RAA respectively.There was no statistically significant(P=0.621).4.Pregnancy outcomes:There were 189 cases of isolated AAA.13 out of 189 underwent induction of labor,the remaining 176 cases were born alive.2 out of 132 cases(1.5%)of ARSA cases occasionally had mild respiratory and/or gastrointestinal symptoms;33 cases of RAA-ALSA,2 cases of them(6.1%)underwent surgical treatment due to vascular ring compression with respiratory and/or gastrointestinal symptoms;5 cases of RAMI,were asymptomatic;There were 6 cases of DAA,3 cases of them(50%)underwent surgical treatment because the trachea was oppressed by vascular rings.There were 54 cases of non-isolated AAA,37 cases underwent induction of labor and 17 cases were born alive,all of these 17 cases had no symptoms of vascular ring compression.Conclusion:1.ARSA is the most common type of AAA.When ARSA combined with other ultrasound malformations or soft ultrasound markers,the risk of fetal chromosomal abnormalities increased significantly.Therefore,to provide evidence-based genetic counseling,other congenital malformations and soft ultrasound markers should be carefully scanned for when ARSA was detected.2.The frequency of chromosomal abnormalities is low in ARSA cases,but it may be the underlying ultrasonic indication for chromosomal detection.There are significant challenges to balance the risks of fetal loss due to invasive procedure and have fetuses with chromosomal abnormalities.In addition,CMA is recommended for isolated ARSA rather than karyotyping.3.The incidence of chromosomal abnormalities in RAA fetuses is high.Whether isolated or not,prenatal invasive procedure is recommended.4.RAMI is often associated with other intracardiac malformations,especially conotruncal congenital heart defects.If RAMI is detected,further echocardiography should be performed to rule out other cardiac structural abnormalities.5.The prognosis of isolated AAA is mainly related to the presence,the shape and compression degree of vascular ring.The prognosis of non-isolated AAA is mainly determined by the concomitant malformations.