National Estimates of the Pubertal Milestones Among Urban and Rural Chinese Girls
Journal of Adolescent Health, 04/03/2012
Sun Y et al. – This study presented up–to–date data on female pubertal timing in a national sample of Chinese Han ethnicity girls and separately for urban and rural areas.Methods
- Girls of Chinese Han ethnicity from grade 1 in elementary schools through grade 12 in junior high schools in eight regions participated in China Puberty Research Collaboration from October 2010 to May 2011.
- At examination, stages of breast and pubic hair development were assessed by trained physicians.
- Data on menses were collected through questionnaire survey.
- A total of 15,388 girls aged 6.0–18.9 years participated in this collaboration study.
- Among them, approximately 53.5% (8,238) came from rural areas.
- The median ages at stage 2 of breast development of Chinese girls were 9.18 (95% confidence interval: 8.91–9.44) years and at stage 2 for pubic hair growth were 11.65 (95% confidence interval: 11.41–11.90) years.
- Girls with body mass index <85th percentile had earlier age for B2 (Tanner stage 2 for breast development), B3 (Tanner stage 3 for breast development), PH2 (Tanner stage 2 for pubic hair development), PH3 (Tanner stage 3 for pubic hair development), and menarche compared with girls with body mass index < 85th percentile.
- Urban girls achieved PH2, PH3, and menarche at a much earlier age than rural girls, except for B2 and B3 attainment.