The conception data supplied by the Office for National Statistics (ONS) are derived by combining birth registration data and abortion notifications. It includes the number of conceptions, the rate of conceptions per 1,000 females and the proportion of conceptions that result in an abortion.
For the purposes of measuring progress against the Government's Teenage Pregnancy Strategy, the under-18 conception rate is used. This is expressed as a rate per 1,000 females aged 15-17. Using rates rather than numbers takes account of changes in the 15-17 female population size and therefore provides a more accurate picture of the proportion of the under-18 population that became pregnant in a given year.
Conception data can be disaggregated to ward level, allowing local areas to target their local strategies in high-rate neighbourhoods. Ward-level data are combined over three years, to comply with ONS's confidentiality rules which do not permit abortion numbers of less than 10 to be published, in order to protect patient confidentiality.
We do not have any plans to change these data collection arrangements.
Between 1998 (the baseline year for the Teenage Pregnancy Strategy) and 2007 (the latest year for which data are available), the under-18 conception rate has fallen by 10.7 per cent; within the overall decline in under-18 conceptions, teenage births have fallen by 23.3 per cent. to their lowest level for over 15 years.