Comparison of Menarche Age between Two Generations

Abstract

Background: During the past century, the mean age at menarche among the North West Iranian girls has decreased. The aim of this study was to compare the age of menarche between two generations and to determine the effect of BMI on the menarche age. Materials and Methods: This cross –sectional study was carried out on 2029 girls of 9-17 years of age during September 2012 to May 2014 in North-West of Iran. Participants were selected by multistage random cluster sampling from school students in urban and rural areas. After measuring their height and weight, relevant data were collected through a questionnaire. Data were analyzed by chi-square, independent-t test and Pearson bivariate correlation Coefficients, using SPSS 16. Results: Out of 2029 girls’ age 9-17 years, the 1600 who were menstruating included in the study. The mean age of menarche in daughters and their mothers were 12.58±1.3 and 13.22±1.22 years, respectively. There was a significant positive correlation between mothers’ and daughters’ menarche age (r = 0.33, P= 0.001). However, a negative significant relation was observed between menarche age and BMI (r= 0.24 P< 0.001). Conclusion: We found that the mean age of menarche was different in comparison with the previous generations. The age at menarche of obese girls is significantly earlier normal weight.