7349 Identifying the Onset of Puberty in Boys Born Small for Gestational Age (SGA)

Abstract Disclosure: S.M. Suco: None. A.C. Keselman: None. M.G. Ballerini: None. M.E. Rodriguez: None. M.G. Ropelato: None. S. Rosenbrock: None. D. Braslavsky: None. R.A. Rey: None. R.P. Grinspon: None. Introduction: Some children born SGA have an earlier pubertal onset and more rapid progression. Therefore, it is essential to identify the onset of puberty to proceed in a timely and appropriate manner. As it has also been suggested that there may be some gonadal dysfunction, the classic markers of pubertal onset, for example, testicular volume ≥ 4ml, may not be appropriate in these cases. Objective: To describe the clinical and biochemical characteristics of pubertal maturation in boys born SGA and determine parameters that best identify pubertal onset. Methods: We perform a retrospective, descriptive study of a cohort of boys born SGA with longitudinal follow-up, at a tertiary pediatric public hospital in Buenos Aires, Argentina. The subjects were selected from 1997 to 2023. Main outcome measures were serum levels of LH and AMH and testicular volume (TV). Additionally, height velocity, bone age, IGF1 and HOMA-IR were also collected to analyze its association with puberty. Pubertal onset was defined as serum LH ≥ 0.3 U/L and/or a decrease in serum AMH ≥ 30%. Results: The cohort included 25 boys born SGA, 24% were born prematurely and 60% were referred for short stature. In 18 boys (72%) AMH decline occurred with testicular volume < 4ml, at a median age of 9.8 yr (IQR 8.3 – 11 yr), and with median TV of 2ml. In 5 boys, LH was ≥ 0.3 U/L when AMH decline >30%. In 14 boys (56%) TV was <4ml when serum LH was ≥ 0.3 U/L. The median age for LH ≥0.3 was 11.3yr (IQR 10.4 – 12.2 yr), with a median TV of 3ml. In 3 boys the decrease in AMH occurred concomitantly with the increase in LH, while in 6 it occurred before.Alongside with the AMH decline, acceleration of bone age was observed in 35%, increase in growth velocity in 29%, increase in IGF1 concentrations in 24% and an increase in HOMA-IR in 26% of the boys. Concomitantly with an LH ≥0.3 U/L, acceleration of bone age was observed in 19%, increase in growth velocity in 25%, increase in IGF1 concentrations in 30% and an increase in HOMA-IR in 50% of the boys. Conclusion: The increase in testicular volume to 4ml, a classic parameter used as a marker of pubertal onset, may not be appropriate in a subgroup of children born SGA. Probably other parameters such as the increase in serum LH or the decrease in AMH should be considered. Presentation: 6/1/2024