ESPE Abstracts

Background: Using ultrasound to examine the glandular breast tissue is a promising method for staging pubertal breast development. However, breast ultrasound for this purpose has not been explored in a large sample of healthy girls in different developmental stages, and normative data have been unavailable.

Objective: To present novel pubertal references for breast ultrasound stages, Tanner breast (B) and pubic hair (PH) stages, and menarche for girls living in Norway.

Materials and Methods: A cross-sectional sample of 703 girls (6.1- 16.2 years) living in Bergen, Norway, were measured and included into the study (Bergen Growth study 2) in 2016-17. All girls were examined with ultrasound to determine the pubertal breast developmental stage (USB). Tanner B and PH stages were assessed clinically. The girls were also asked about menarche. Ages at entering USB, Tanner B and PH pubertal stages 2-5, and menarche were estimated using a generalized linear and a generalized additive models. Pubertal breast staging with USB and Tanner B were compared using kappa statistics with linear weights and Spearman's correlation.

Results: Median age (p3, p97) at onset of breast development was 10.2 (7.81, 12.62) years for USB 2, and 10.38 (8.18, 12.58) for Tanner B2. For PH2 and menarche, estimated median ages at onset were 10.88 (8.61, 13.15) and 12.67 (11.04, 15.88) years, respectively. Significant correlation was found between USB and Tanner B breast development stages (r=0.95, P<0.001), and were in very good agreement (kappa 0.87; 95% confidence interval: 0.85, 0.88).

Conclusion: Staging of pubertal breast development done with ultrasound provided similar ages at pubertal onset compared to traditional Tanner B staging. The estimated ages at onset of breast development, PH and menarche in our study are in accordance with recent European studies.