It may prevent your getting onto one of the mentored pilot schemes some airlines offer (via OAT/CABAIR/CTC/FTE etc..) as it would appear you'll only have a single A-Level in ICT(unless you are doing other A-levels), but it won't prevent you from obtaining a pilots license via self sponsorship I'm assuming you achieved a good GCSE grade in maths to get onto a maths A-Level course anyway.