Age at onset of menarche in apparently healthy urban school children- a cross sectional study

Objective: To study the relationship between anthropometric indices and age at onset ofmenarche in urban school girls.
Methods: Apparently normal 249 adolescent girls between age group of 11 to 15 years studying from class 6 to 10th were taken for study. Girls with prolonged medication and chronic diseases were excluded. Height, weight were measured and BMI was calculated. Age at menarche was determined by status quo method.
Results: Among 249 adolescent girls, 188(75.5%) attained menarche and 61 girls (24.5%) had not yet attained menarche. Median age at onset of menarche is 12 years in girls and 15 years in mothers. Majority of the girls attained menarche at 12yrs (40.42%).Mean (SD) BMI in menstruated and non-menstruated girls were 21.32 (4.5) and 18.6 (3.7) .There was a positive co-relation between BMI and age at menarche (p = 0.001). Girls with higher BMI attained menarche at early age. Daughters attained menarche earlier than the mothers which is significant by Kruskal Wallis test with p value of 0.038.
Conclusion: Menarche occurs earlier in daughters than their mothers.Higher BMI is associated with lower menarche age.