Full data on teen pregnancies for 2007 will be published by the Office for National Statistics (ONS).
Figures from the first three-quarters of the year showed a rise among under-18s.
From January to March 2007, the teen pregnancy rate was 42.6 girls per 1,000 and it was 42.7 for the period April to June.
For July to September, the rate was 39.9.
Overall figures for 2006 showed that 41 girls in every 1,000 fell pregnant in that year.
The Government has pledged to halve teenage pregnancy rates among girls under 18 by half by 2010 but is widely expected to miss that target.
A 2004 aim to cut the rates by 15 per cent from the base year of 1988 was missed.
Gill Francis, chair of the Teenage Pregnancy Independent Advisory Group, said the expected rise today was "challenging".
She said the Government's strategy to drive down teen pregnancy rates was working in areas where it was fully implemented.
For example, in Blackburn in the north west, measures to talk to young girls and support them and their parents were having an effect.
"But in other areas they have not been holding it together in the same way and they may be doing just a bit of it.
"Teen pregnancy is a complex issue but we do know what needs to be done."
Ms Francis said measures such as working with young people, sex education and encouraging parents to talk to their children all had an effect.
Also, young new mothers could be helped to assess whether it was a good idea to go on and have a second baby.