Objective: The aim of this study is to determine our region’s median values of first trimester screening used in pregnancy and to compare the test results calculated regarding the median values in prenatal test programme. Material and Method: The biochemical parameters of first trimester screening measured in 565 pregnants who applied Education and Research Hospital in the years of 2016 and 2017 for first trimester screening were retrospectively examined. Multiple of Median (MoM) values, calculated in regard to the weekly median values in the used first trimester screening programme, were compared to the MoM values, calculated in regard to our region’s median values and furthermore the weekly median values in the used programme were compared to our region’s median values.

Results: In this study, it was found out that both free ß-human Chorionic Gonadotropin (ß-hCG) and Pregnancy Associated Plasma Protein-A (PAPP-A) median values were lower in the 11th, 12th, and 13th weeks in comparison to the median values of the used programme. Conclusion: We consider that it would be more appropriate for every city or region to evaluate trimester screening by finding median values, which are specific to its own population, and for each laboratory to interpret trimester screening in regard to its own median values. Furthermore, we are of the view that evoking consciousness by sharing specific median values with clinicians might be better than today’s applications.

Prenatal diagnosis Down syndrome Trisomy Prenatal screening