Factors contributing to early menarche in school girls

To assess the average age of menarche in Pakistani girls from different socioeconomic backgrounds. This was a cross sectional study design carried out on female students studying in different schools of Karachi in 2014. Girls aged 10-14 years age were included. Schools from all three socio economic strata were selected through random sampling technique from a list of schools having health care services. Data was collected through a self-administered questionnaire translated in Urdu where required. Height and Weight was measured through calibrated instruments. Sample size was n=385 based on maximum proportion of 50%. Analysis was done on SPSS version 20. Chi-square and ANOVA was applied after checking data for normality. The total sample size was 275 after excluding poorly filled questionnaires. The mean age of menarche in our sample population was 11.73±1.2 years. Out of the total participants 127 (46%) students had reached the age of menarche. It was found that mean age of menarche was highest in participants of Kashmiri origin 14.5±0.1 years and lowest mean age was observed in those of Gujrati origin at 11.0±0.1 years (p 0.036). When mean age of menarche was compared with socioeconomic class highest mean age was observed in lower class 12.13 ±0.1 (p 0.268). Our study reveals a decline in the mean age of menarche of at least 2 years in girls aged 10-14 years.