[36] Congenital Hypothyroidism Flashcards
What is congenital hypothyroidism?
A condition of thyroid hormone deficiency present at birth
Why is congenital hypothyroidism important to detect in neonatal screening?
- Relatively common
- Preventable cause of severe learning difficulties
What is the most common cause of sporadic congenital hypothyroidism?
Maldescent of the thyroid and athyrosis
What normally happens to the thyroid during early fetal life?
The thyroid migrates from a position at the base of the tongue to its normal site below the larynx
What happens to the thyroid in maldescent?
The thyroid remains as a lingual mass or a unilobular small gland
What is the reason for the failure of formation or migration of the thyroid?
Not well understood
Other than maldescent of the thyroid and athyrosis, what are the causes of congential hypothyroidism?
- Dyshormonogenesis
- Iodine deficiency
- Hypothyroidism due to TSH deficiency
What is dyshormonogenesis?
An inborn error of thyroid hormone synthesis
What is hypothyroidism due to TSH deficiency usually associated with?
Pituitary dysfunction
What is the significance of hypothyroidism due to TSH deficiency being associated with pituitary dysfunction?
The pituitary dysfunction usually manifests in other ways before hypothyroidism is evident
What are the risk factors for dyshormonogenesis?
More common in ethnic groups with consanguineous marriage
What is the problem with the early diagnosis of congenital hypothyroidism?
They are difficult to differentiate from normal in the first month of life
What happens to the clinical features of congential hypothyroidism with age?
They become more prominent
What are the clinical features of congential hypothyroidism?
- Feeding problems
- Constipation
- Faltering growth
- Prolonged jaundice
- Pale, cold, mottled dry skin
- Coarse facies
- Large tongue
- Hoarse cry
- Goitre
- Umbilical hernia
- Delayed development
How are most infants with congenital hypothyroidism picked up?
Routine neonatal biochemical screening
