Earlier Age of Menarche Is Not Associated with Earlier Age at First Sexual Intercourse

Previous cross-sectional and retrospective studies suggest early menarche is associated with earlier age of first sexual intercourse (FSI). These investigators used data from the Western Australia Pregnancy Cohort Study to prospectively examine this association. Extensive information was collected at ages 1, 2, 3, 5, 8, 10, 14, 17, and 20 years for 2868 live-born children (1405 girls).

A total of 554 girls provided 17-year follow-up information and valid sexual activity data. By age 17 years, 50% had initiated sexual activity. Median age of FSI for the entire cohort was 16 years. FSI by age 16 years was reported by 56% of girls with early menarche (age <12 years), 50% with average menarche (ages 12-13 years), and 41% with later menarche (age…