ESPE Abstracts

Background: Transient neonatal hypothyroidism (T N HT) is a rare entity important to recognize. It is due to placental transfer of antibodies antirécepteurs of pituitary TSH. It is distinguished from permanent congenital forms of hypothyroidism, because it requires only limited substitution treatment in time.

Objective and hypotheses: Report the observations of 6 children who presented T N HT.

Method: This is a retrospective study of six children(with two brothers) hospitalized for suspiscion of hypothyroidism. All children underwent a complete clinical examination with questioning of the parents, hormonal exploration (FT4, TSH, AC Anti-TPO), and cervical ultrasound. Once the diagnosis established, treatment with levothyroxine is undertaken. Regular reassessments were performed.

Results: The average age at diagnosis is 3 months (20 days-5 months). Sex ratio F/G is 4/2. Hypothyroidism was diagnosed in front of clinical signs in four cases, persisting neonatal jaundice in two cases. Biological assessment confirmed hypothyroidism: FT₄ average 6.5 pmol/l, mean TSH 35 μ/l. TPO antibodies (TPO) were found in all cases (mean 30 ng/ml). Questioning the parents revealed an autoimmune thyroiditis in mothers. Clinical and radiological examinations did not show any malformation. LT₄ replacement therapy undertaken was screeching halt after 4.85 months (3–6). Hormonal reassessments showed no abnormalities and anti TPO were négatives. Growth stature and psychomotor development were normal.

Conclusion: T N HT is very rare. It must be recognized precociously, to avoid inadequate diagnostic and therapeutic measures.