Young age at first intercourse and subsequent risk-taking behaviour: An epidemiological study of more than 20,000...

First intercourse at the age of 14 years or younger is usually considered high-risk behaviour for sexually transmitted infections (STIs). It has been linked to other types of risky behaviour in women, while conflicting results have been obtained for men. The aim of the study was to estimate the prevalence of first intercourse at a young age in various birth cohorts of men and to determine any association with later risky behaviour.

We studied 22,979 randomly selected men aged 18-45 years from the Danish general male population who responded to a self-administered questionnaire. Multiple sexual partners over a lifetime, multiple new sexual partners within the past 6 months, intercourse with a commercial sex worker, having an STI, binge drinking and current smoking were considered risky behaviour.

First intercourse at the age of 14 years or younger was more prevalent in younger (14%) than in older (10%) birth cohorts and among men with shorter schooling. Young age at sexual debut was associated with a more than twofold increase in the risks for subsequent risky behaviour.

More than 10% of Danish men first had sex at an early age, and this was closely related to subsequent risk-taking behaviour.