Factors associated with teenage pregnancy in the Scandinavian countries.

Aims: Teenage pregnancy may have negative consequences for the mother and the infant. The aim of the study was to examine whether selected individual factors occurring early in life were associated with teenage pregnancy.

Methods: In a population-based, cross-sectional questionnaire study among 34,455 women from Denmark, Norway, and Sweden aged 20-45 years, who had first sexual intercourse (FSI) at age 13-19 years, we assessed the association between early smoking and drinking initiation (i.