Association of puberty timing with parental age at childbirth among primary and secondary students in Beijing

Abstract

ObjectiveTo explore the relationship between puberty timing and parental age at childbirth among primary and secondary students and in Beijing, and to provide a reference for further comprehending puberty development of children and adolescents. MethodsUsing a self-designed questionnaire and the Puberty Development Scale (PDS), we conducted a survey among 3 441 students recruited with stratified cluster sampling at 16 primary and secondary schools in urban and rural regions of Fangshan district of Beijing during October 2012. Multivariate logistic analysis was adopted to investigate the relationship between parental age at childbirth and puberty timing among the students. ResultsAmong 3 113 students (1 602 boys and 1 511 girls) with complete information, the prevalence of early and delayed puberty were 14.73% and 9.61% in the boys; but in the girls, the prevalences were 12.84% and 10.99% respectively. After adjusting confounding factors such as overweight and obesity, low birth weight, and family economic condition and taking the students with the parental ages of 20 – 24 years as the controls, multivariate logistic analyses showed following results: (1) the boys with the paternal age of ≥ 35 years at childbirth were at an increased risk of early puberty (odds ratio [OR] = 2.36, 95% confidence interval [95% CI]: 1.05 – 5.32); (2) the boys with the paternal age of 30 – 34 years at childbirth were at a decreased risk of delayed puberty (OR = 0.42, 95% CI: 0.18 – 0.97); (3) the girl students with elder parental age at childbirth were at an increased risk of early puberty (for paternal age of 30 – 34 years: OR = 1.87, 95% CI: 1.10 – 3.19; for paternal age of ≥ 35 years: OR = 5.20, 95% CI: 2.68 – 10.08; for maternal age of 30 – 34 years: OR = 2.21, 95% CI: 1.32 – 3.70; for maternal age of ≥ 35 years: OR = 4.14, 95% CI: 1.79 – 9.53); and (4) after further adjusting paternal/maternal age at childbirth, the girl students with the paternal age of ≥ 35 years were at an increased risk of early puberty (OR = 4.18, 95% CI: 1.73 – 10.13). No significant correlation was observed between delayed puberty timing and paternal/maternal age at childbirth in girl students. ConclusionThe elder paternal age at childbirth is an independent risk factor for earlier or later puberty timing among primary and secondary boy students, and the elder paternal age is also an independent risk factor for earlier puberty among primary and secondary girl students. The results suggest that childbearing at an appropriate age should be promoted in young couples.

Keywords

• parental age at childbirth
• primary and secondary students
• pubertal development