Clinical significance of secondary results from non-invasive prenatal testing / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the accuracy of copy number variations (CNVs) detection by non-invasive prenatal testing (NIPT) in addition to its routine targets and clinical significance of such CNVs for the reduction of fetuses born with chromosomal microdeletion/duplication syndromes.</p><p><b>METHODS</b>From October 2014 to October 2015, 14 235 pregnant women volunteered to participate in the study. Fifteen cases detected with chromosomal CNVs by the NIPT decided to undergo prenatal diagnostic procedures including amniocentesis, G-banded karyotyping and chromosomal microarray analysis (CMA). All such cases were routinely followed up after birth.</p><p><b>RESULTS</b>Among the 14 235 subjects underwent NIPT, 18 cases were detected with Down syndrome, 4 with trisomy 18, and 2 with trisomy 13, in addition with 24 cases of CNVs. For the latter, 15 (including 11 cases with microdeletions and 4 cases with microduplications) participated in further prenatal diagnosis. In 13 cases (86.7%), the results of CMA were consistent with those of NIPT. On the other hand, only 7 out of the 15 cases showed a positive result with karyotyping, suggesting a rather high rate of missed diagnosis (46.2%). Of note, karyotyping has identified partial inversion of chromosome 9 in one case.</p><p><b>CONCLUSION</b>As a screening tool, NIPT has a high accuracy for the detection of CNVs. However, as this method is still under improvement, it is more of a reminder rather than a diagnostic tool with full capability.</p>

A feasibility study of coelocentesis in prenatal diagnosis / 中国医师杂志

Objective To explore the feasibility of coelocentesis in prenatal diagnosis.Methods Coelocentesis were applied on 58 women scheduled for at 6～12 weeks of gestation,and fetal heart rate before the procedure and 1,5,30 minutes afterwards and hemorrhage of amnionic cyst was observed.Y gene of sex-determining region was detected by polymerase chain reaction,and compared with chorionic villi sample.Results The total achievement ratio of coelocentesis was 96.6% of all cases in five minutes.The coelomic fluid was successfully aspirated at first attempt in 93.2% at 7～10 week's gestation,25.0% at 6～7weeks and 50.0% at 10 ~ 12 weeks.There was no significant difference in FHR between before coelocentesis and afterwards (P＞0.05).The detection accurate rate of SRY was 91.1%,all female fetus were matched with those observation by chorionic villi sampling,and only 5 male fetus were not matched,the accurate rate was 80.8%.Conclusion Coclocentesis has the advantage of simple procedure,safe and high feasibility.The optimal time of coclocentesis is in the 7th to 10th week of gestation.