ESPE Abstracts

Background: The average age at pubertal onset is declining worldwide which has received a lot of scientific and public attention. This secular trend is accompanied by an increasing number of children diagnosed with precocious puberty in many countries worldwide. However, there is less focus on the secular changes in the upper and lower boundaries (+/- 2 standard deviation (SD)) for pubertal onset and very little is known about whether a secular trend in the incidence of delayed puberty exists.

Aim: To assess the incidence of delayed puberty in Denmark and evaluate if the incidence of delayed puberty is changing over time.

Methods: This population-based, 20-year cohort study used national registry data for all youth in Denmark registered with an incident diagnosis of delayed puberty (E 30.0) in the Danish National Patient Registry from 1998 to 2017 using the International Classification of Diseases, Tenth Revision (ICD-10). We applied the minimum diagnostic age limit for delayed puberty (girls > 13 years, boys > 14 years).

Results: Overall, a total of 1139 children (827 [73%] boys) were registered in Denmark (1998-2017) with an incident diagnosis of delayed puberty. The 20-year mean annual incidence rates were 2.3 per 10 000 boys and 0.8 per 10 000 girls, corresponding to an average yearly number of 41 boys and 16 girls per year in Denmark.

Conclusion: In our nationwide study we report low incidence rates for delayed puberty (equal to > 2 SD) compared to the expected incidence of 2.5% of the population. We found that a diagnosis of delayed puberty is much more frequent among boys compared to girls (3:1), with no apparent secular changes in the incidence despite changes in puberty timing in the general population.