The proportion of A-level entries receiving the highest grades has fallen this summer, with the share getting the top A* grade dropping to a six-year low.
Entries achieving a grade of A or above were also down, plummeting by nearly a percentage point compared with last year.
This year 7.8 per cent of all UK entries received an A* – a 0.2 percentage-point fall on 2018, and the lowest percentage since 2013.
The fall was bigger for entries receiving an A or above – this accounted for 25.5 per cent of all entries, compared with 26.4 per cent in 2018.
However, the overall pass rate – the proportion of entries receiving an A*-E grade – remained unchanged, at 97.6 per cent.
The drop in top grades could be because a larger proportion of 18-years-olds sat A levels this year.
A-level results day 2019: More girl entries in sciences
While overall entries were down 1.3 per cent, this was smaller than the 2.9 per cent reduction in the size of the 18-year-old population, meaning that the proportion of the cohort taking A levels increased slightly.
This year saw a further closing of the gap between boys and girls when it comes to the top grades. While a higher proportion of male entries scored the A* (8.2 per cent compared with 7.5 per cent of female entries), girls overtook boys for entries receiving an A grade or better (25.5 per cent of female entries, compared with 25.4 per cent of male entries).
And for the first time, total female entries in the sciences overtook male entries.
Philip Wright, director-general of the Joint Council for Qualifications, which represents exam boards, said: “All students across the UK receiving their A-level results today should be proud of their achievements.
“They’ve worked hard over the last two years and it is a moment for them, together with their teachers, families and friends, to celebrate.
"This year’s pass rate is stable across A levels, and it is particularly encouraging to see the rise in young women being inspired to take science A levels. This year, for the first time, female entries have overtaken male entries in the sciences. We have also seen a rise in entries for subjects such as history, geography, computing and political studies. I wish all students success in their future courses, study and careers.”