Immunoassay biomarkers of first and second trimesters: a comparison between pregnant Syrian refugees and Turkish women

Background: It was aimed to investigate maternal serum hormone values used for aneuploidy screening, demographic characteristics and fetal measurements in the population of pregnant Syrian refugees (PSRs) and to compare with data from pregnant Turkish women (PTW). Material and methods: The study assessed data from 2697 pregnant who underwent triple and double screening tests, including 1738 Turkish and 959 Syrian women. The maternal serum biomarkers, demographic characteristics and fetal sonography measurements were compared and biases were calculated. By multivariate linear regression analysis, group-specific regression coefficients were estimated. Results: Mean total age and weight were found to be significantly different and lower in PSRs in all gestational ages evaluated (p < 0.001; p < 0.001). The first trimester, median biases for f beta-hCG were found to be higher by 38% and 24.5% for weeks 11 and 13, respectively. In the second trimester, median values of t beta-hCG showed negative biases of 11.8% and 21.2% on weeks 16 and 19 in PSRs, respectively ( p < 0.001). It was considered that ethnicity has a stronger effect on first trimester hormone biomarkers than second trimester. The ethnic diversity showed the greatest effect on f beta-hCG. Conclusion: Race/ethnicity-specific regression coefficients and median values based on validated risk estimations should have to be used for fetal aneuploidy risk reports.