The Clinical Application Of Late Amniocentesis

Background:The purpose of the study was to evaluate the indications,complications,results of chromosomal microarray analysis and pregnancy outcomes of late amniocentesis at the Prenatal Diagnosis and Fetal Medicine Center of the Third Affiliated Hospital of Guangzhou Medical University.Methods:The study included females who received amniocentesis between 24+0 to 39+0weeks(late amniocentesis group)from January 1,2014 to December 31,2022.The aim was to compare their indications,complications,results of chromosomal microarray,and pregnancy outcomes with patients who had amniocentesis at 16+0 to23+6 weeks(routine amniocentesis group).Information was retrieved from patient medical records,checked by research staff,and analyzed.Results:This study analyzed 1348 pregnant women(1380 fetuses)who underwent late amniocentesis,as well as a control group of 2170 pregnant women(2207 fetuses).In the amniocentesis group,ultrasound abnormalities detected in late pregnancy were the most common indication for the procedure,and the proportion was higher than that in the routine amniocentesis group(88.41% vs.46.67%,P<0.001),followed by abnormal prenatal screening results(8.04%,111/1380)and abnormal diagnostic test results(0.72%,10/1380).The overall incidence of complications in the late amniocentesis group was 4.15%(56/1348),included preterm birth and fetal intrauterine death,with incidence of 2.60%(35/1348)and 1.48%(20/1348),respectively.The overall complication rate of the routine amniocentesis group was3.32%(72/2170),which was not significantly different from that of the late amniocentesis group(P=0.209).In the late amniocentesis group,chromosomal microarray analysis was performed on 1380 cases,with 66 cases showing aneuploidy,67 cases with pathogenic copy number variants,and 62 cases with uncertain results.In the routine amniocentesis group,chromosomal microarray analysis was performed on 2207 cases,with 271 cases showing aneuploidy,83 cases with pathogenic copy number variants,and 91 cases with uncertain results.In the late amniocentesis group,58.84% of the fetuses were live birth and 34.06% were terminated.In the routine amniocentesis group,57.59% of the fetuses were live birth and 34.53% were terminated.Conclusions:Late amniocentesis is a safe and reliable method to detect late-onset fetal abnormalities with advanced genetic technologies.Chromosomal microarray analysis may result in uncertain findings,including variants of uncertain significance,which underscores the importance of comprehensive and informed prenatal genetic counseling.