Age (years)

19 ± 4

Age at menarche (years)

12 ± 2

Regular menstrual cycles

15 (62.5%)

Length of menstrual cycles (days)

5 ± 2 (range 2 - 10)

Menstrual blood flow

・ normal

・ heavy

・ scant

13 (54%)

8 (33%)

3 (13%)

Severe dysmenorrhea

・ constant

・ frequent

18 (75%)

6 (25%)