江苏地区孕中期唐氏综合征筛查母血清标志物中位倍数标化方法的探讨

Evaluating the applicability of MoM in second trimester maternal serum to screening for Down＇ s syndrome in Jiangsu province

目的探讨我国唐氏综合征产前筛查时应用国外软件MultiCalc作内嵌参数估计的适用性。方法通过构建血清指标中位浓度与孕龄间的回归关系，选取最优模型得到指标中位浓度。并对中位倍数（multiple of the medlian, MoM）与体重的关系进行探讨，选取最优模型得到体重调整后的MoM值。结果在未经体重校正的条件下，江苏地区孕中期孕妇的甲胎蛋白（alpha fetal protein, AFP）平均水平比MultiCalc软件内嵌参数源人群（欧洲白人）A即平均水平要高出16％，而游离β-人绒毛膜促性腺激素（β-human chori onic gonadotrophin, β-hCG）要高出14％。经过体重校正后，MultiCalc软件计算的表达成MoM值的AFP平均水平为0．99，游离β-hCG平均水平为1．02，而模型标化的血清标志物的MoM中位数均为1．00。结论江苏地区孕中期妇女的血清指标平均水平与MultiCalc软件内嵌参数源人群没有差别，MultiCalc软件适合于江苏省孕妇的唐氏综合征筛查。

Objective To study the applicability of MultiCalc software to prenatal sereening of Down＇ s syndrome in Jiangsu province, China. Methods The gestational age-specific median of maternal serum marker was calculated by means of regression method. Regression functions for adjustment of Multiple of the Median （MoM） by weight were established for our own population. Results Before the adjustment by weight, the average level of alpha fetal protein（AFP） was 16% higher and the free β-human chorionic gonadotrophin （β-hCG） was 14% higher than those of the Caucasian in MultiCalc software respectively. But when the AFP and free β-hCG results were converted to weight-adjusted MoM levels, the values were 0.99 and 1.02 respectively. The median of MoM of AFP and the free β-hCG were 1.00 through the regression model of gestational age and weight adjustment. Conclusion There was no difference of average weight-adjusted MoM levels between the Jiangsu population and the Caucasian, and the MultiCalc software was applicable to maternal serum screening for Down＇ s syndrome of Jiangsu.