Risk Taking Behaviour Lay Summaries

Younger age at first menstrual period is not a risk factor for younger age at first sexual intercourse

Keywords: risk factors, menarche, sexual intercourse, adolescent

What is already known about this subject:

  • Girls who have their first sexual intercourse at an early age often engage in more risky sexual behaviour (such as unprotected sex, multiple partners and inconsistent use of contraceptives), with far-reaching consequences including teenage pregnancy, sexually transmitted infections and lower educational attainment.
  • It is thought that girls who reach reproductive maturity early are more likely to engage in sexual intercourse at a younger age, but this has not yet been properly tested.

What this Raine study adds:

  • Age at menarche (first menstrual period) and age at first sexual intercourse data from female Raine participants revealed that a younger age at menarche does not increase the likelihood of early first sexual intercourse.
  • The results were consistent whether age at first sexual intercourse was measured using calendar age or as time since menarche.
  • Health interventions targeting early age at first sexual intercourse need to consider indicators other than just age at menarche.

Marino, J. L., Skinner, S. R., Doherty, D. A, Rosenthal, S. L., Cooper Robbins, S. C., Cannon, J., & Hickey, M. (2013). Age at menarche and age at first sexual intercourse: a prospective cohort study. Pediatrics, 132(6), 1028-36. doi:10.1542/peds.2012-3634. [publink]