OBJECTIVE: To assess the usefulness of triple-marker screening for Down syndrome 
in Venezuela.
METHOD: Maternal serum concentrations of alpha fetoprotein (AFP), beta human 
chorionic gonadotropin (beta-hCG), and unconjugated estriol (uE3) were measured 
weekly in 3895 women from the 15th to the 20th week of pregnancy. 
Population-specific likelihood ratios were determined and used to calculate the 
risk of fetal Down syndrome for each pregnancy.
RESULTS: The median multiple of the median values for AFP, beta-hCG, and uE3 
concentrations were 0.69, 2.10, and 0.67 for the affected pregnancies. The 
likelihood ratio for a positive result was 1:19. The detection and 
false-positive rates were 69.23% and 5.8%.
CONCLUSION: These findings were consistent with reported data and therefore 
confirmed triple-marker serum screening as effective and suitable for prenatal 
care in Venezuela. Latin American governments and Health Agencies should 
recommend offering this screening method to all pregnant women.