Application of ROC curve for evaluation of the effect of prenatal screening during second trimester of pregnancy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To develop a method for evaluating the feasibility of prenatal screening using local median value and determining the cut-off value.</p><p><b>METHODS</b>With receiver operating characteristic curve (ROC) analysis, results of second trimester prenatal screening calculated by a local median value in a new model and the built-in median value in 2T software were compared. The cut-off value was set by serial analysis of true and false positive rates and other relevant data.</p><p><b>RESULTS</b>The ROC curve has accurately estimated the difference in the screening efficacy between a local median value and that embedded in the 2T model, and established a reasonable cut-off value for the laboratory based on false positive rate and detection rate.</p><p><b>CONCLUSION</b>The method of ROC curve can be used to evaluate the performance of local median value in prenatal screening and to test the rationality of cut-off value established in the laboratory. As the result, a better cut-off value may be derived.</p>

Establishment of median values for second trimester maternal serum biomarkers in Weihai region / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish the median values for second trimester biomarkers in Weihai region, and to assess its value for improving the performance and efficiency of prenatal screening.</p><p><b>METHODS</b>Maternal serum alpha-fetoprotein (AFP) and free beta human chorionic gonadotropin (Free beta-hCG) were determined for 24 400 pregnant women at 105 to 146 gestational days. A regression equation was derived after adjusting for different gestational ages. The median values were further adjusted with body weight.</p><p><b>RESULTS</b>The median values of AFP and Free beta-hCG were respectively 6% and 24% higher than those embedded in a 2T software. After adjusting with gestational age and weight, there is a significant difference in multiple of the median (MoM) of serum biomarkers between local population and that embedded in the 2T model.</p><p><b>CONCLUSION</b>To establish the median values for different gestational ages for local region may help to improve the efficiency of prenatal screening.</p>