Age at menarche in northwest Indian females and a review of Indian data.

Data on menarcheal age were collected by a status quo method on a sample of 709 girls drawn from an urban Punjabi population of Chandigarh. Probit analysis provided a median age at menarche of 13.2 +/- 0.04 years with a standard deviation of 1.09. Menarche occurred in all cases between 10 and 16 years. Comparison with other Indian populations shows that populations at higher altitude and in peninsular India have a later maturation than the present sample.