Generally, menarche is considered an indicator of girls' sexual maturation. In Thailand, this study on the menarcheal age in female pupils was conducted in Bangkok, and the central, northern, northeastern and southern regions of Thailand, which differ in their geography, tradition and customs. In carrying out the research, 8,200 questionnaires were distributed to female pupils aged 10-17 years. The result was that the mean menarcheal age was 12.3 years. For the length of menstrual period, it was found that 83.7 per cent had a period of less than 7 days and 75.7 per cent used 2-4 pieces of sanitary napkins per day. For the regularity of menstrual period, 48.5 per cent had a regular period and 41.8 per cent had a period once within 2 months. For the persons whom these female pupils needed for advice about menarche, the study indicated that mothers were mostly needed. For the mean menarcheal age reported in each region, it was found that in the central region the mean menarcheal age was 12.5 years, the North was 12 years, the Northeast was 12.4 years and the South was 12.7 years. These data prove to be statistically significant, that is the lowest menarcheal age of female pupils was in the North while the highest was in the South. In terms of nature and characteristics of female pupils' menstruation in 4 regions there was no difference. When comparing the BMI value of female pupils already having a period in each region, the result was that there was no difference. The BMI value of those already having a period was higher than those not having had a period; and in the latter group, the BMI value of female pupils in the North was the highest while that in the Central region was higher than in the Northeast and the South.
PIP: Generally, menarche is considered an indicator of girls' sexual maturation. In Thailand, this study on the menarcheal age in female pupils was conducted in Bangkok, and in the central, northern, northeastern, and southern regions of Thailand, which differ in their geography, traditions, and customs. 8200 questionnaires were distributed to female pupils aged 10-17 years. Mean menarcheal age was found to be 12.3 years. Concerning the menstrual period, it was found that 83.7% had a period of less than 7 days and that 75.7% used 2-4 sanitary napkins per day. Concerning the regularity of the menstrual period, 48.5% had a regular period and 41.8% had their period once within 2 months. Concerning the persons from whom these female pupils sought advice about menarche, the study indicated that mothers were most frequently consulted. Concerning mean menarcheal age, it was found that in the central region it was 12.5 years, in the north it was 12 years, in the northeast it was 12.4 years, and in the south it was 12.7 years. These data prove to be statistically significant; that is, the lowest menarcheal age was found in the north while the highest was found in the south. In terms of the nature and characteristics of female pupils' menstruation in the four regions, there was no difference. When comparing the BMI value of female pupils already having periods in each region, no difference was found. The BMI value of those already having periods was higher than those who had not yet had a period; and, in the latter group, the BMI value of female pupils in the north was the highest, while that in the central region was higher than that in the northeast and the south.