First trimester detection of trisomy 16 using combined biochemical and ultrasound screening

Abstract

What's already known about this topic? Four previously reported cases of trisomy 16 have shown reduced levels of pregnancy‐associated plasma protein‐A during first trimester screening for trisomy 21. Isolated increases in free β human chorionic gonadotrophin and nuchal translucency were observed in these four cases.What does this study add? During first trimester screening for aneuploidy, we observed a further 28 cases of trisomy 16, all of which had reduced levels of pregnancy‐associated plasma protein‐A consistent with previous reported cases. Increased free β human chorionic gonadotrophin and increased nuchal translucency were not a consistent finding in our 28 cases.