Estimation of median second trimester screening test values at a single hospital

INTRODUCTION: The aim of this study was to determine the median values of the maternal serum triple screen test components, beta human chorionic gonadotropin (β-hCG), alpha-fetoprotein (AFP), and unconjugated estriol (uE3), at a single hospital in order to enhance prenatal diagnostic ability and to report fetal anomaly risks more accurately and reliably.
METHODS: The triple test results of 692 pregnant women were evaluated retrospectively. The median values specific to a single laboratory were determined and compared with those of a fetal risk assessment software program.
RESULTS: The laboratory estimated β-hCG medians according to gestational week were higher than those of the 14th and 16th week generated by the software program and lower in the other weeks. The serum estimated medians for AFP were higher than those of the program in all weeks except the 14th week. The difference between weeks 15, 16, and 17 was significant (p<0.001). For uE3, the estimated medians were lower than the software results and the difference was significant at weeks 15, 16, 17, and 18 (p<0.001).
DISCUSSION AND CONCLUSION: The determination of regional median values would provide more accurate and reliable results for prenatal screening tests.