New GCSE 'guinea pigs' in Blaenau Ffestiniog worried
The introduction of new, Wales-only GCSEs in September will lead to the curriculum here becoming overcrowded, a teaching union has warned BBC Wales.
Year 10 pupils from September will be the first to follow new English-language, Welsh and maths courses.
The ATL union said it would have an impact on optional subjects like French, geography and history.
The education minister said the Welsh government had worked with schools to advise on creating timetables.
Pupils from Ysgol y Moelwyn in Blaenau Ffestiniog, Gwynedd, had some concerns, while teacher Sharon Davies said the changes would help improve standards.