Clinical features

Clinical features are often subtle with most newborn infants not diagnosed at birth (due to the presence of maternal thyroid hormones which crossed the placenta) (1).
Presenting features include:

• coarse facies, with macroglossia
• umbilical hernia
• cold or mottled skin
• hoarse cry
• hypotonia
• hypothermia
• prolonged jaundice
• poor feeding
• constipation
• presence of a palpable goitre suggests a goitrogen aetiology
• the posterior fontanelle remains open, and closure of the anterior fontanelle is delayed
• the infant may be anaemic
• if untreated mental retardation may develop (1)

An increased risk of congenital malformations are seen to be associated with congenital hypothyroidism e.g. - a study of 1420 infants with congenital hypothyroidism revealed that 8.4% had extra thyroidal congenital malformations of which majority were cardiac malformations (1).

Reference:

• (1) Rastogi MV, LaFranchi SH. Congenital hypothyroidism. Orphanet J Rare Dis. 2010;5:17