Analysis of the effect of expanded non-invasive prenatal testing in prenatal screening population during pregnancy / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical effect of expanded non-invasive prenatal testing (NIPT-plus) for prenatal screening.@*METHODS@#The screening result, prenatal diagnosis and pregnancy outcome of 3700 pregnant women who volunteered NIPT-plus screening at our center from September 2018 to December 2019 were reviewed.@*RESULTS@#Among the 3700 pregnant women, 74(2.0%) were scored positive for clinically significant fetal chromosomal abnormalities and underwent NIPT-plus screening. Sixty three women with a high risk underwent invasive prenatal diagnosis, among whom 19 were diagnosed, which yielded a positive predictive value (PPVs) of 30.2% (19/63). Statistical analysis showed that NIPT-plus has higher PPVs for common aneuploidies and low-to-medium PPVs for sex chromosome aneuploidies and microdeletion/microduplication syndromes.@*CONCLUSION@#As a screening technique, NIPT-plus has broader applications compared with conventional techniques, and has reference value for clinicians and pregnant women during pregnancy.

Is it necessary to choose NIPT-plus for pregnant women who opt for non-invasive prenatal testing? A study of 50 cases / 中华医学遗传学杂志

OBJECTIVE@#To explore whether it is necessary to choose NIPT-plus for the prenatal screening of pregnant women.@*METHODS@#The results of NIPT and NIPT-plus sequencing data, fetal DNA concentration, prenatal diagnosis and pregnancy outcome of 50 pregnant women were compared.@*RESULTS@#Compared with NIPT, NIPT-plus attained similar fetal DNA concentration and a 4.4-fold increase in sequencing data. NIPT was able to detect 4 cases of 21-trisomy, 2 cases of 18-trisomy, and 9 cases of sex chromosome aneuploidies (SCAs) signaled by NIPT-plus, but missed one 18-trisomy, and failed to detect rare chromosome aneuploidies (RCAs) and microdeletion/microduplication syndromes (MMS). The PPVs of NIPT-plus for 21-trisomy, 18-trisomy, SCAs, MMS and RCAs were 100%, 100%, 44.4%, 30.4% and 0%, respectively. And those of NIPT for 21-trisomy, 18-trisomy, and SCAs were 100%, 100%, and 44.4%, respectively.@*CONCLUSION@#It is necessary for pregnant women to select NIPT-plus to improve the detection rate of common trisomies, SCAs and disease-specific MMS, therefore reduce the occurrene of birth defect.

Results of non-invasive prenatal testing for 2473 women with twin pregnancy / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of non-invasive prenatal testing (NIPT) for the detection of fetal chromosomal aneuploidies in women with twin pregnancy.@*METHODS@#A total of 2473 women with twin pregnancy underwent the NIPT test to assess the risk for fetal chromosomal aneuploidies from January 2016 to September 2019. Those with a high risk by NIPT were confirmed by amniocentesis or chorionic villus sampling. All cases were followed up to evaluate the positive prediction value of NIPT for twin pregnancies.@*RESULTS@#Among the 2473 women, the NIPT test has identified 31 cases (1.25%) with a high risk for fetal chromosomal aneuploidies, which included 5 cases of trisomy 21, 1 case of chromosome 21 deletion, 4 cases of trisomy 18, 7 cases of sex chromosome abnormality and 14 cases of microdeletion and microduplication. By invasive prenatal diagnosis or chromosomal karyotyping analysis of neonates, 5 cases of trisomy 21, 3 cases of trisomy 18, 1 case of sex chromosome abnormality, and 2 cases of microdeletion and microduplication were confirmed, which yielded a positive predictive value of 100%, 75%, 25% and 25%, respectively.@*CONCLUSION@#NIPT can be used for the screening of fetal chromosomal aneuploidies in women with twin pregnancy with high accuracy. The method is non-invasive, safe and effective for the screening of fetal chromosomal aneuploidies, in particular trisomy 21.