Multiple of the median correction of Down's syndrome serum markers with pregnant body weight / 中华检验医学杂志

ABSTRACT

Objective With Pregnant women weight correction for serum marker Multiple of Median (MoM) of First trimester and second-trimester,integrated screen-ing for Down's syndrome (DS),can reduce the false positive rate.Methods The same pregnant woman were taken venous blood vessels with sterile vacuum during the first trimester (11-13 W(+ 6) d) and the second trimester (15-20 W(+ 6) d),Alpha-fetoprotein (AFP),serum free beta-human chorionic gonadotrophin (Free beta hCG) and pregnancyassociated protein-A (PAPP-A) of three kinds of serum marker screening indicators were assayed by Using Time-resolved fluoroimmunoassay (TRFIA).Screening for risk assessment software was used to calculate serum marker Multiple of Median,To assess the risks of 7 997 cases of local pregnant women DS,To construct the weight equation of local population using nonlinear weighted regression method,With maternal weight correction for serum marker Multiple of Median (MoM) of local pregnant women,Comparing the changes of screening index MoM before and after correction,chi square test to compare the detection rate and false positive rate.Results MoM values of three kinds of serum markers (al-pha-fetoprotein,free beta subunit of human chorionic gonadotropin,pregnan-cy-associated plasma protein A) decreased with the weight increasing,Screening index MoM after correction weight equation,the screening of false positives for crowd from 4.12％ down to 3.86％ (x2 =0.021,P ＞ 0.05).Setting threshold (cut-off) at 1/270,and no change detection rates were 71.4％ the local population before and after correction weight equation.Conclusion Maternal weight may affect the results of Down's syn-drome sereening.When screening proposal to set up,it is worth making weight cor-rections for serum maker multiple of median in order to get accurate risk calculation results.