Adult height of children born small for gestational age treated with growth hormone and gonadotropin-releasing hormone analogs in Southern Brazil.

Abstract

Objective: To evaluate adult height and identify the factors contributing to its achievement in patients born small for gestational age (SGA) treated with recombinant human growth hormone (rhGH).

Subjects and methods: This retrospective study includes data of SGA children treated at a pediatric endocrinology center. Inclusion criteria were SGA birth (birth length and/or weight < -1.28 standard deviation score (SDS), absence of catch-up growth by the age of four years, rhGH treatment for more than 12 months, and recorded adult height. Birth size SDS was calculated using Intergrowth-21st (gestational age ≥ 33 weeks) or Fenton (<33 weeks) standards. Patients with uncontrolled chronic diseases, genetic syndromes, or growth hormone deficiency were excluded. An increase of 0.6 SDS or more was considered a positive response.

Results: Twenty-four patients (14 boys) were included, with an average gestational age of 38.0 (range: 33.0-40.0) weeks, birth weight of -1.3 ± 0.9 SDS, and birth length of -2.4 ± 0.7 SDS. They were treated with rhGH starting at an average age of 10.3 ± 2.6 years for a duration of 5.4 ± 2.3 years. Height SDS increased from -2.6 ± 0.4 SDS to -1.2 ± 0.6 SDS, which was comparable to the target height SDS (-1.3 ± 0.9; p = 0.3). Although 18 children were classified as good responders, 6 did not achieve a final height SDS > -2.0. Adult height was correlated with the increment in height SDS and growth velocity during the first year of treatment. No significant differences were observed between children classified as SGA by birth weight or length < 10th percentile and those by weight or length < -2.0 SDS.

Conclusion: In this cohort of children born SGA with short stature, rhGH treatment effectively improved adult height. Given the diverse causes of being born SGA, the response to rhGH therapy may vary.