The high failure rate in last year's maths AS-level - double that of other subjects - has led to a slump in the numbers taking the full A-level.
Results day will show pupils have opted for "easier" A2 qualifications in a bid to keep their grades up. This shift can be seen as a natural consequence of the Government's A-level reforms which encourage pupils to study subjects for a year before narrowing their choice.
The provisional national figures, released on Thursday, are also expected to show a drop in the overall number of A-level entries. The reason for the decline is unclear, but it could mean some students are taking two, rather than three, A-levels and completing an extra AS in upper sixth to raise their point score.
The waiting will be over for about half a million teenagers next week when around 1.6 million results are published. However, research by Nottingham University, due out on Monday, shows that many of them feel their achievements are undermined by claims by some commentators that exams are getting easier.
Last year, the debate reached fever pitch when retired chief examiner Jeffrey Robinson chose the week of the GCSE results to claim record pass rates were "fixed". Teachers and pupils complained that their big day had been ruined by Mr Robinson's allegations.
The Government's exam watchdog is pushing for the national results to be kept secret next year until weeks after students receive theirs, so their celebrations are not overshadowed.
Sir William Stubbs, Qualifications and Curriculum Authority chairman, is in favour of the move. He said students should receive results even earlier, while national pass rates are made public much later, "after students have gone through their personal ups and downs".
George Turnbull, spokesman for exam board AQA, said: "It is a serious problem. What is reported in August does not give a true picture."
However, one exam board insider said delaying the date of publication could encourage even more speculation about the national figures and leave ministers open to accusations of media manipulation.
Concerns have been raised that some students could be facing incomplete results next week because schools and colleges entered students late or failed to get coursework marks in before the deadline.
Tony Higgins, chief executive of the Universities and Colleges Admissions Service, said the results process was going to schedule, but some exam boards had warned of missing grades for some students.
"Edexcel said two weeks ago that they might have no results or late results for these candidates," he said.
More than 2,500 Scottish higher entries will have incomplete grades when the results are released north of the border on Tuesday.
Late results mean universities cannot confirm offers and students could risk losing their places on undergraduate degree courses.