Figure showing age at menarche

Cumulative percentage of girls reporting menarche with increasing age.
Participants with imputed month of menarche omitted from plot

Age of menarche in contemporary British teenagers and those born between 1950 and 1965

Reference and region	No of participants	Date of birth	Median age of menarche (95% CI)
Tanner,⁴ London	7000	1950-7	13.0 (12.9 to 13.1)
Roberts et al,^w1 north east England	1307	1954-9	13.3 (13.2 to 13.4)
Billewicz et al^,w2 north east England	699	1962	13.4 (13.3 to 13.5)
Roberts et al^,w3 north west England	1274	1960-5	13.3 (13.2 to 13.4)
Current study
Region:
Southern England	575	1982-6	13.1 (12.8 to 13.2)
North west England	358		12.9 (12.7 to 13.2)
South Wales	233		12.9 (12.6 to 13.2)
Ethnicity:
European	1068		13.0 (12.8 to 13.2)
South Asian	79		13.1 (12.5 to 13.3)
Other*	19
Parent's occupation:
Non-manual	448		12.9 (12.7 to 13.2)
Manual	375		13.1 (12.8 to 13.2)
Unclassified	343		13.1 (12.7 to 13.2)
Overall	1166		12.9 (12.8 to 13.1)