Trisomy 21 screening based on first and second trimester in a Taiwanese population.

Objective: This study investigates the performance of first- and second-trimester screening tests for detecting fetal trisomy 21 in a Taiwanese population.

Materials And Methods: This multicenter study 29,137 cases enrolled the chromosomal abnormality screening between 2013 and 2014 two years period from Taipei city. There were 23,990 was done the first trimester screening using a combination of fetal nuchal translucency, maternal serum β-human chorionic gonadotropin, and pregnancy-associated plasma protein-A between 11 and 13 weeks of gestation age.