| In recent years,with the improvement of assisted reproductive technology and the opening of the two-child policy,the incidence of twin pregnancy has increased.There are more risk factors in twin pregnancy,and the incidence of chromosomal aneuploidy is higher than that of single pregnancy,making the screening of twin chromosomal aneuploidy a hot topic in the field of prenatal testing.The current prenatal screening methods for chromosomal aneuploidy in twin pregnancy are ultrasound and serological screening,and the detection results of these two methods are not ideal.Pregnancy screening with non-invasive prenatal testing(Non-invasive Prenatal Testing,NIPT)technology is mainly aimed at screening for chromosomal aneuploidy,especially for the relatively high incidence of three types of chromosomal trisomy diseases: T21,T18 and T13.However,it is not yet clear how the NIPT technique can be used to detect twin pregnancies.In order to clarify the actual efficacy of NIPT in detecting chromosomal aneuploidy in twin pregnancy,this topic summarized the research data of multiple research units in the early stage,and carried out a systematic analysis on this basis.In addition,there are currently no NIPT screening guidelines for twin pregnancies.On the basis of confirming the effectiveness of NIPT screening,this study will use the big data of BGI’s NIPT twin detection to analyze the potential risks of chromosomal trisomy in twin pregnancy and the detection time window,and provide it for twin pregnancy subjects More targeted pre-pregnancy care and prenatal screening guidelines.Methods:Relying on Google,Pub Med,and CNKI database platforms to retrieve and screen out non-repetitive cases related to T21,T18,and T13 and with verification of pregnancy outcome results.Analyze the sensitivity,specificity,positive predictive value(PPV)and negative predictive value(NPV)of NIPT in detecting T21,T18 and T13.Subsequently,based on the NIPT test data of 31997 twins from January 2015 to January 2019,the influence of factors such as age,BMI,and test time window on the results of twin pregnancy tests was analyzed.Results:The study included 10 valid research literatures,and the total number of 5,217 test persons whose pregnancy outcome had been conformed.69 data about T21 have been concluded in the study.The 10 studies have a risk of bias in selecting patients,testing indicators,reference standards,procedures and testing schedules,among which patients have the greatest risk of deviation.Sensitivity was 98.2%(95% CI,0.832-0.998);specificity was 99.95%(95% CI,0.997-0.999);positive predictive value(PPV)and negative predictive value(NPV)were 98.55%(68 / 69)and 99.92%(5144/5148).The detection rate of the 10 studies included and the heterogeneity evaluation results of false positives were 0.021 and 0.013.20 data about T18 have been concluded.The sensitivity of NIPT to detect T18 was 88.9(95% CI,0.648–0.972);the specificity was 99.97(95% CI,0.997–1.000).The positive predictive values PPV and NPV were 95%(19/20)and 99.99%(4040/4141).Summarizing the detection rate and the false positive heterogeneity evaluation results among the 10 included studies were 0.008 and 0.003.Only 4 positive T13 cases have been concluded,the data is too small to perform statistical evaluation of efficacy.There are 9489 results have been included in the research.Compared to the normal BMI group(0.24%),the positive rate of the BMI high group(0.19%)or low group(0.15%)has no significant difference,p> 0.05.The positive rate of 26 to 29 years old twin pregnancy population was 0.10%,significantly higher than that of singleton 0.02%.There is little difference in the positive rate between the twins and singletons in the 30-34 age group.Early pregnancy detection rate is higher than the positive detection rate in the second and third trimesters.The positive test rates at 12 weeks(0.69%)and 13 weeks of pregnancy(0.51%)were significantly higher than those at 16 weeks(0.10%)and 17 weeks(0.11%)P <0.05.Conclusions:In this study,NIPT detection of trisomy 21,in twin pregnancies was confirmed to be accurate and T18 detect specific good as well.More study need to be performed to evaluate the accuracy of NIPT detection T13.It is also recommended to advance the NIPT prenatal screening time to 26 years old more early age.Reproductive age is a risk factor for the occurrence of chromosomal aneuploidy in twin pregnancy,while the pre-pregnancy weight is not.Twin pregnancies are advised to undergo NIPT testing in the first trimester,with 12 weeks and 13 weeks as the best.It is recommended that the NIPT test be used simultaneously with other screening methods,which can provide a comprehensive judgment basis for the implementation of clinical diagnosis and intervention measures... |
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