Changing patterns of teenage pregnancy: population based study of small areas.

OBJECTIVES To measure the impact of socioeconomic deprivation on rates of teenage pregnancy and the extent of local variation in pregnancy rates in Scotland, and to examine how both have changed over time. DESIGN Population study using routine data from hospital records, aggregated for small areas. SUBJECTS Female teenagers resident in Scotland who were treated for pregnancy in an NHS hospital in either 1981-5 (62 338 teenagers) or 1991-5 (48 514) and who were aged 13-19 at the time of conception. MAIN OUTCOME MEASURES Pregnancy rates per 1000 in age group and the proportions of pregnancies resulting in a maternity (live birth or stillbirth) in teenagers aged 13-15, 16-17, and 18-19. RESULTS From the 1980s to the 1990s pregnancy rates increased differentially according to levels of local deprivation, as measured by the Carstairs index. Among teenagers aged less than 18 the annual pregnancy rate increased in the most deprived areas (from 7.0 to 12.5 pregnancies per 1000 13-15 year olds and from 67.6 to 84.6 per 1000 16-17 year olds), but there was no change, on average, among teenagers in the most affluent areas (3.8 per 1000 13-15 year olds and 28.9 per 1000 16-17 year olds). Among 18-19 year olds the pregnancy rate decreased in the most affluent areas (from 60.0 to 46.3 per 1000) and increased in the most deprived areas (from 112.4 to 116.0 per 1000). The amount of local variation explained by deprivation more than doubled from the 1980s to the 1990s. The proportion of pregnancies resulting in a maternity was positively associated with level of deprivation, but the effect remained similar over time. CONCLUSION From the 1980s to the 1990s the difference in rates of teenage pregnancy between more affluent and more deprived areas widened. This has implications for allocating resources to achieve government targets and points to important social processes behind the general increase in the number of teenage pregnancies in Scotland.