Comparison Of Different Serum Screening Tests For Aneupolyhaploid In Second-trimester Of Pregnancy

Objective:To compare and analyse different serum screening tests for Down's Syndrome and other major chromosome abnormalities tested by Time-Resolved Fluorescence ImmunoAssay and ChemiLuminescence ImmunoAssay,and to preliminarily evaluate Double,Triple and Quadruple Serum tests from a cost-effectiveness perspective.Materials and Methods:Serum samples of 888 second-trimester singleton pregnancies were collected from prenatal screening and diagnosis center of Peking Union Medical College Hospital from Jan.2007 to May.2008.For All the samples AFP, TotalβHCG,uE3,DIA concentrations were measured by CLIA,and AFP,free-βHCG and uE3 concentrations were measured by TR-FIA.Risk values of double,triple and Quadruple test were calculated respectively in LifeCycle and CLIA Risk Calculation Software.Multiple of Medians(MoM) of each marker tested by CLIA were calculated. Descriptive statistic and regression analysis were used to obtain gestational age-specific Medians and weight adjustments.False positive rate of double,triple and Quadruple test measured by CLIA,double and triple test measured by TR-FIA were compared respectively.FPR Comparison of the same marker combination in between CLIA and TR-FIA and a cost-effectiveness analysis were also taken.Results:1.Serum sample of 888 second-trimester singleton pregnancies were collected,of which 876 were obtained all four markers(AFP,totalβhCG,uE3,DIA) values measured by CLIA and 870 were obtained three markers(AFP,free-βhCG,uE3) values measured by TR-FIA,and 860 by both.2.Four markers' values of quadruple test were measured by CLIA and 21 and 18 trisomy risks were calculated.Muliple of Medians of each marker were obtained and corrected by two different sets of weight adjustment formula.There were significant differences between each pair of them analysed by paired-sample T test.There was poor linear of inverse regression for Median MoMs of DIA to weights.The False Positive Rate under the same detection rate of double,triple and quadruple test were 9.84%,7.67%and 5.49%respectively.FPR would decrease around 2%when a new marker were introduced.3.Three markers' values of triple test were measured by TR-FIA and 21 and 18 trisomy risks were calculated in LifeCycle.The False Positive Rate under the same detection rate of double,triple test were 8.97%and 2.91%respectively.4.FPRs of double test measured by CLIA and TR-FIA were similar(9.84%,8.97%), but TR-FIA was more superior in triple test.(7.67%compared to 2.91%).5.The costs of one double,triple or quadruple test was estimated around 100～120RMB,150～180RMB or 250～300RMB respectively.Conclusions:1.Screening performance was increased by adding new markers when measured by CLIA.2.Triple test performed better than double test when measured by TR-FIA.3.The screening performance of double test measured by CLIA was similar to TR-FIA,but TR-FIA was more superior in triple test.4.Second -trimester double-marker serum test was more cost-effective in China, and triple/quadruple test was suitable to be selectively used in well developed cities.