Age at Pubertal Development in a Hispanic-Latina Female Population: Should the Definitions Be Revisited?

STUDY OBJECTIVE

To assess pubertal events in a Hispanic female population and to create normograms of puberty.

DESIGN

Longitudinal.

SETTING

University facility.

PARTICIPANTS

Five hundred forty-nine girls from the Growth and Obesity Chilean Cohort study.

INTERVENTIONS

Follow-up twice a year beginning at age 6 years.

MAIN OUTCOME MEASURES

Breast development, pubic hair development, and age. Breast development (B2, B3, and B4) and pubarche (P2) were determined. Age at menarche was obtained from the adolescents and their mothers. Age and growth velocity at peak height velocity were calculated.

RESULTS

In girls, B2, B3, and B4 occur at median ages of 9.2, 10.2, and 10.9 years, respectively. The median age at P2 was 9.7 years. The mean age at peak height velocity and the growth velocity were 10.6 years (SD = 1.1) and 8 cm/y, respectively. The mean age at menarche was 11.9 years (SD = 1.1); only 2.8% (15 /530) of girls experienced menarche after 14 years and 1.9% before 10 years. The mean interval time between B2 and menarche was 2.5 ± 1.0 years. Transient thelarche occurred in 8.6% of girls.

CONCLUSION

This longitudinal cohort shows that thelarche occurred 1.2 months later than previously reported in cross-sectional studies. Conversely, we found that pubic hair appeared 12 months earlier and menarche occurred 9 months earlier than previously reported. These findings are important in setting normalcy data and avoiding unnecessary clinical consultations.