Objectives To compare the risk factors of self-reported abortion in St Petersburg, Estonia and Finland, which are neighbouring areas having different abortion rates.

Methods Data from four population-based questionnaire surveys (Finland 1992 and 1999; St Petersburg 2003; Estonia 2004) were used. With the exception of the 1992 Finnish survey (based on interviews) all were postal surveys. There were 1070 respondents in Finland (78% and 52% response rates), 1147 (68%) in St Petersburg, and 5190 (54%) in Estonia.

Results The prevalence of self-reported abortions was highest among women in St Petersburg and among the two oldest age groups of Russian-speaking Estonians. In all areas women with a history of abortion were more likely to have low education, children, a history of multiple partners and to have had their first intercourse when younger than 18 years. Insufficient use of reliable contraception, both at first and last intercourse, was the only risk factor that was more common in St Petersburg and in Estonia than in Finland. In Estonia, more Estonian than Russian-speaking women used reliable contraceptives.

Conclusion The comparison of three areas suggests that high abortion rates are related to low contraceptive use and not to other risky sexual behaviour.