| Objective:1.To understand the attitude,awareness rate and interpretation of antenatal screening practitioners and pregnant women towards NIPT,and to provide basis for improvement in key areas such as NIPT-related knowledge education and norms of pre-test counseling;2.To strengthen the understanding of the status quo of screening for aneuploidy in twin pregnancy at home and abroad,and to clarify the application value and potential risks of NIPT in screening for aneuploidy in twin pregnancy;3.To understand the detection status of NIPT in twins in our hospital in recent years and the optimization effect after enrichment of fetal free DNA,so as to provide the basis for further clinical promotion and implementation of NIPT.Methods:1.Questionnaire survey was adopted to design questionnaires according to relevant technical standards and to conduct a questionnaire survey among relevant practitioners in several medical units of different levels and antenatal screening and diagnosis centers in guilin;2.Through the retrieval,screening and evaluation of clinical studies on screening aneuploidy of twin pregnancy using fetal free DNA in pregnant women’s plasma published before December 2020,10 high-quality studies were included for Meta-analysis;3.Retrospective analysis of non-invasive prenatal screening of peripheral blood samples of pregnant women with twin pregnancy using semiconductor sequencing platform in the Obstetrics Clinic of *** Maternal and Child Health Hospital from 2017 to 2020,and evaluation of the effect.Results:1.A total of 721 questionnaires were collected,of which 674 were valid,with an effective rate of 93.48%.Among them,278 were filled by medical personnel and 443 were filled by pregnant women.93.62% of respondents believed that NIPT should be provided to women with twin pregnancies,and the vast majority of respondents believed that providing NIPT for twin pregnancies was risky.Prenatal screening practitioners did not know enough about NIPT in twin pregnancies,and prenatal diagnostic physicians and laboratory staff had a higher awareness rate of NIPT than obstetricians(P=0.000).Only 6.50% of clinicians believed that individual genetic counseling for twins was comprehensive and detailed.Pregnant women are less informed about NIPT and rely on physician consultation and instruction.Compared with single pregnancy women,pregnant women with twin pregnancies have a stronger willingness to accept NIPT and are more likely to refuse prenatal diagnosis.2.A total of 10 valid research literatures were included in this study,and a total of 5,217 cases were included including pregnancy outcome verification results.The 10 studies all had the risk of bias in the selection of patients,test indicators,reference standards and procedures,and test schedule,among which the risk of bias was the greatest in the selection of patients.Sixty-nine samples with positive T21 validation results were included,with a sensitivity of 98.2%(95%CI,0.832-0.998).The specificity was 99.95%(95%CI,0.997--0.999);PPV and NPV were 98.55%(68/69)and 99.92%(5144/5148),respectively.Heterogeneity evaluation results of each study were 0.021 and0.013,respectively,indicating low heterogeneity among groups.Twenty samples with T18 positive results were included,with a sensitivity of 88.9(95%CI,0.648--0.972).The specificity was 99.97(95%CI,0.997--1.000).PPV and NPV were 95%(19/20)and 99.99%(4040/4141),respectively.Heterogeneity evaluation results were 0.008 and 0.003,respectively,with low heterogeneity among each group.The total number of subjects with positive validation results in testing T13 was 4,and statistical evaluation of efficacy could not be conducted.3.NIPT was used to detect the fetal free DNA in peripheral blood of12～22+6 weeks pregnant women.The sensitivity,specificity,false positive rate and positive predictive value of NIPT detection for trisomy 21 and trisomy 13 were 100%,100% and 100%,respectively.The positive predictive value of NIPT detection for trisomy 21 and Trisomy 13 were 100% and 50%,respectively.(In this study,there was no T18 case.)Conclusion(s):1.The key to the rational and correct application of NIPT lies in how clinicians interpret NIPT and how pregnant women understand it.Currently,clinicians and pregnant women with twins have little or no in-depth understanding of NIPT,so standardized management,personnel training,education and follow-up should be strengthened to help pregnant women make informed choices to a greater extent.2.In twin pregnancy,the efficacy of NIPT in screening trisomy 21 in twin pregnancy is similar to the results reported in single pregnant women,superior to early pregnancy combined screening and middle pregnancy combined screening,and the accuracy is close to the gold standard.Due to the small number of cases of trisomy 18,it is not possible to give an accurate assessment.3.NIPT has a high accuracy in detecting chromosomal aneuploidy in twins,but it cannot determine the number and location of abnormal fetuses,which must be confirmed by prenatal diagnosis. |
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