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.