[Associated factors related to first spermatorrhea and menarche among high and primary school students, in Chongqing].

Objective To understand the status and correlative factors on menarche and first spermatorrhea among children and adolescents, in Chongqing, in order to provide theoretical basis for carrying out sex and health education in this population. Methods By random stratified and cluster sampling, 10 498 students (5 372 boys and 5 126 girls), 5 to 18 years old and living in Chongqing urban districts, were enrolled. General situation and physical features of the population were studied. Statistics analysis system included logistic regression methods, t-test and chi-square test. Results For urban kids, first experience of spermatorrhea was 0.218 years later than those living in the rural areas (Z=-73.287,P 0.05). However, significant difference appeared in average family income (χ2=6.175,P=0.046) between two groups of girls. Data from the logistic analysis showed that BMI, hip circumference, height, weight, number of children in the family, time of sleep and the diet structure were associated with menarche. Correlative factors of boys' first spermatorrhea would include: high-energy snacks, hip circumference, weight, height, school type and mother' s education level (P<0.05). Conclusion First spermatorrhea and menstruation of boys and girls were closely related to environment of the family, diet and the time of sleep. Key words: Emission; Menarche; Related factors