Distribution of Biochemical and Ultrasound Markers Values in the First Trimester Screening Program in Timisoara

The aim of our study was to analyze the distribution of biochemical markers (free- hCG and PAPP-A) and nuchal translucency (NT) values and their deviation from expected median in our screening program. NT, free- hCG and PAPP-A values were measured in first trimester sera of 1313 singleton pregnant women. The age (mean standard deviation) of pregnant women at the time of screening was 28.94 4.95 years and the gestational age was 87.66 4.74 days. The value of NT (median standard error of mean) was 0.87 0.01 multiple of median corrected (MoMc), of free-b hCG was 1.07 0.02 MoMc and of PAPP-A was 1.06 0.01 MoMc. Since the huge majority of pregnant women carried a healthy fetus it was assumed that the median value of measurements was equal to 1 MoMc and the deviation from median was equal to null. Our results showed that the greatest deviation from the expected median (-0.13 MoMc) was recorded for the NT measurement while the deviation for the free- hCG and PAPP-A values was 0.07 respectively 0.06. In conclusion the main disturbing factor in calculating the aneuploidy risk was the measurement of NT. A systematic audit of laboratory and ultrasound measurement is necessary.