ESPE Abstracts

Background: Few studies have investigated in detail how the pubertal breast maturation in girls is related to the pubertal growth spurt in a longitudinal setting. The golden standard for assessment of secondary sex characteristics for girls includes breast development (B1-B5)¹. The different maturation stages follow the increasing estradiol production from the ovaries also giving rise to the pubertal growth spurt. The QEPS-growth model makes it possible to conduct detailed analyses of pubertal growth and separate total growth into specific pubertal (P-function) height gain and basal/prepubertal growth (QES-functions) ^{2, 3}.

Objective: To investigate the relationship between the development of breast maturation in healthy girls and their pubertal growth spurt. To visualize the individual variation in the relation between breast maturation and the attained specific pubertal height gain.

Method: The study group included 32 healthy girls who were longitudinally followed during puberty with 1-4 yearly visits, including height measurements and assessments by trained paediatric endocrinologists of breast maturation, by the method of Tanner¹. Maturation was assessed 2-9 times for each girl. Analyses of growth patterns were done with the QEPS-growth model^{2, 3}. Pubertal heights were expressed in both cm and by QEPS-growth estimates, i.e. how many % of the specific P-function-pubertal growth that was attained at each visit. Breast maturation was related to % of the specific P-function-pubertal gain attained (P%).

Results: As expected, with increasing stages of breast maturation the specific P-function-pubertal height gain increased, and each girl followed an individual trajectory. However, the individual variation was considerable as seen by the range in the Table below:

Conclusion: The specific pubertal gain in height has for the first time been analysed and visualized in relation to breast maturation during puberty in girls. We found a clear relation between breast maturation and specific pubertal height gain, demonstrating the validity of the QEPS-model in this new research question. Each girl followed her trajectory, with broad inter-individual variation in breast maturation versus P%, of the specific P-function-pubertal height gain.

References: 1.Marshall WA, Tanner JM. Arch Dis Child 1969 Jun;44(235): 291-303

2.Nierop AFM, et.al. J.Theoretical.Biology,406(2016): 143–165

3.Holmgren A, et.al. BMC.Pediatrics,2017;Apr19;17(1): 107