The congenital central hypothyroidism (CCH) incidence is estimated at 1:18,000-30,000 neonates and most are included in multiple pituitary deficiencies (MPD). Clinical depend on the etiology, the deficit severity; other associated hormonal alterations and the age of diagnosis. Neonatal screening (NS) for congenital hypothyroidism that includes T4 facilitate its diagnosis.
Objetives: To evaluate the characteristics of patients with CCH in the Basque Country.
To evaluate the success of T4 in our NS for the early diagnosis of MPD.
Material and Methods: Retrospective study of 20 CCH controlled by pediatric endocrinologists of the Basque Country in the last 21 years [1997-2009: 426,174 live newborns]. The results of the NS performed at 48 hours of life, including T4 and TSH on filter paper, as well as clinical, hormonal and image data have been collected. The lower cut-off point for T4 in NS is 6 μg/dL. The patients were classified into 3 subgroups according to [T4]:<6 μg/dL (n=4), 6-8 μg/dL (n=8) and>8 μg/dL (n=6). MPD was diagnosed with affectation ≥2 hormonal axes. Adrenal insufficiency (AI) detected in the first year of life was considered determinant of severity. Two cases without T4 levels were excluded.
Results: The CCH incidence is 1/22,308 live newborns. All patients (61% males) had MPD and pituitary malformation; The mean gestational age was 39 weeks (range:33-41) and the mean birth weight 3,175 g (range:2,300-4,100). 11/18 patients had AI and their average [T4] in NS was lower [AI:6±2.8 μg/dL versus non-AI:8.9±3.5 μg/dL;U-Mann-Whitney P=0.03].
Four patients had [T4]<6 μg/dL in NS. Three of them were diagnosed of AI in the first month of life but the fourth maintains adrenal function at 5 years. 7/8 of patients with [T4] between 6-8 μg/dL were diagnosed of AI before 12 months of age, associating clinical symptoms, alterations of the pituitary and/or other hormonal deficits. Only 1/6 of patients with [T4]>8 μg/dL was diagnosed with AI.
Conclusions: 1. The determination of T4 in the NS allowed an early diagnosis of 25% of the CCH, as well as the suspicion of MPDs.
2. Most of the MPDs including AI were diagnosed in the first year of life. In all of them, the [T4] in the NS was ≤8 μg/dL. Just considering a clinical point of view, we think it could be interesting to increase the lower cut-off of T4 in our NS.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology