ESPE Abstracts

Background: Congenital hypothyroidism (CH) is a treatable thyroid hormone deficiency that causes intellectual disabilities and growth deficiency if not detected and treated early.

Material and Methods: We retrospectively analyzed the medical records of 22 patients, 13 (59%) females and 9 (41%) males, with positive CH screening at birth and confirmed by TSH & FT4 serum concentrations measurements, thyroid ultrasound and physical examination. In unclear cases, a second ultrasound was performed at 6 months of age. The average follow-up period was 19 months. The evolution and compliance under levothyroxine treatment were analysed. TSH & FT4 values and levothyroxine dosage during the follow-up were collected.

Results: The average age of CH diagnosis was 29 days (3-90 d.). Ultrasound detected: thyroid dysgenesis in 16 (72.7%) & dyshormonogenesis in 6 (27.2%) patients. Among dysgenesis: 14 cases (63.6%) of agenesis, one case each of hemiagenesis (4.5%) and hypoplastic thyroid gland (4.5%). L-T4 starting daily dose varied between 7-15 µg/kg (median 10.2 µg/kg); The maintenance dose was adjusted according to body weight, TSH and FT4 values. During the follow-up, at 12 months mean L-T4 dose was 3 µg/kg/day. Presented below is the average monthly dose in the first 12 months:

We found an association between the normalization of TSH and the L-T4 dose: the higher the starting dose, the faster TSH normalised.

Conclusions: We want to highlight the benefits of CH screening: early detection and treatment of CH through neonatal screening prevent irreversible neurodevelopmental delay. L-T4 treatment should be started as soon as possible with a starting dose of up to 15 µg/kg/day, adjusted to the whole spectrum of CH.