Résumé
INTRODUCTION: It is reported that analytical precision in maternal serum screening tests for Down's syndrome has a direct effect on the precision of the risk estimation. Recently, an automatic immunoassay analyzer, which can measure the alphafetoprotein (AFP), chorionic gonadotropin (CG) and unconjugated estriol (uE3) was introduced, and we evaluated the analytical characteris-tics and defined the median value in healthy pregnant women. METHOD: We measured the AFP, CG and uE3 with Access(R) (Beckman Coulter, Fullerton, CA, USA) and evaluated the precision, the low detection limit, the linearity and we defined the median value in the women who were in 15-20 weeks of pregnant. RESULT: Between-run precisions of AFP, CG, uE3 were 1.12%, 2.01%, and 2.59%, respectively. The lower detection limit of AFP, CG, uE3 was 0.08 ng/mL, 0.16 mIU/mL, and 0.015 ng/mL, respec-tively. All three items passed the lack of fit test of the linear regression. Median values for the gesta-tional period (15- 20 week) of AFP, CG, uE3 were 37.47- 69.01 ng/mL, 41.44- 29.10 IU/mL, and 0.871- 2.008 ng/mL, respectively. CONCLUSION: The automatic immunoassay analyzer used for screening for Down's syndrome was satisfactory for the analytical features and showed median values similar to that of the Wald's. We conclude that Access(R) could be used for screening pregnant women for Down's syndrome with better precision and convenience.