Thyroid axis impairment in short children with intrauterine growth retardation (IUGR).

KESELMAN A; CHIESA A; VIEITES A; HEINRICH JJ; GRUÑEIRO-PAPENDIECK L.

Rotterdam Holanda

Congreso; 45 Annual Meeting of the European Society for Pediatric Endocrinology; 2006

ESPE

IUGR is a common cause of short stature. Around 85 % of this children experiment catch-up during the first 2 or 3 years of age, while the remaining 15% does not. Thyroid  evaluation is included when assessing causes of  short stature. Thyroid function  was analysed in 51 short IUGR children (29 females), aged ( X±SD) 5.96 ± 3.75 years (range 1,3 -15) with a mean height SDS of -2.7 ± 0.73, and birth weight and length of 1854 ± 536 gr and 43.7 ± 3.5 cm. respectively. TSH, free T4 or total T4, antythyroid antibodies and a TRH stimulation test up to 90 minutes had been performed. 4/51 patients (8.5%) had circulating levels of antythyroid antibodies, only one with associated hypothyroidism. The remaining 47 patients, were grouped according to basal TSH levels in G1: (n:23) TSH <5mU/l (X±SD 3.41± 1.16 mU/l) and G2 : TSH (n:24) TSH >5 mU/L(X±SD 7.31 ± 2.1mU/l). An abnormal TRH-TSH test was found in 4/23 children of G1 and 21/23 of  G2 . No statistical significant differences were found in chronological age, gestational age , birth weight or height between groups . FT4 ( ng/dl) (1.29±0.20 vs 1.30± 0.26) and T4 ( ug/dl) (9.84±2 vs 9.05± 2) weren’t different either. In conclusion, 32/51 (62.7%)  of the evaluated IUGR patients showed thyroid  abnormalities. Of these, 12.5% had thyroid autoimmunity and the other 87.5% exhibited abnormal TSH levels and/or TSH/TRH abnormalities  suggesting central hypothyroidism, affecting either the TSH molecule or the storage and secretion of TSH. As intrauterine growth retardation may permanently influence the endocrine system by affecting its programming during development, further follow-up is required to confirm these findings and to assess their natural evolution and clinical impact.