Decrease in menarcheal age from 1966 to 1983 in Denmark.

Mean age at menarche was estimated by the status quo method in the same region of Denmark in 1965-66 and 1982-83 in 983 and 1 591 girls, respectively. During that period menarcheal age decreased by 4 months from 13.40 to 13.03 years, subsequent to a similar decrease from 1949-50 (2) to 1965-66. Comparison with recent data from the other Nordic countries, except Norway, indicates that age at menarche is now close to 13 years, and a halt in the trend towards earlier menarche is not evident.