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Head circumference, height, bone age and weight in 103 children with congenital hypothyroidism before and during
Insights
Congenital hypothyroidism can cause increased head circumference and delayed bone age. Early thyroid hormone therapy normalizes growth, while late treatment may lead to persistently larger head size and shorter stature.
Area of Science:
- Pediatric Endocrinology
- Developmental Biology
- Neonatal Screening
Background:
- Congenital hypothyroidism (CH) is a condition affecting thyroid hormone production from birth.
- CH can impact growth and development, including head circumference, height, bone age, and weight.
- Early diagnosis and treatment are crucial for optimal outcomes in children with CH.
Purpose of the Study:
- To investigate the effects of thyroid replacement therapy on head circumference, height, bone age, and weight in children with congenital hypothyroidism.
- To compare outcomes based on the age at which thyroid hormone therapy was initiated.
- To determine the long-term growth trajectory and normalization potential following treatment for CH.
Main Methods:
- A longitudinal study of 103 children with congenital hypothyroidism.
- Patients were categorized into four groups based on the age of treatment initiation (neonatal screening, 1-3 months, 4-12 months, >1 year).
- Measurements of head circumference, height, bone age, and weight were recorded before and up to 8 years of thyroid replacement therapy.
Main Results:
- Children diagnosed via neonatal screening (treated <2 weeks) showed normalization of head circumference, bone age, height, and weight.
- Late-treated groups (>1 month) exhibited initially normal or increased head circumference, with catch-up growth in height, bone age, and weight.
- Late-treated children (>1 year) had persistently larger head circumference and remained shorter than normal even after 8 years of therapy.
Conclusions:
- Congenital hypothyroidism is associated with altered head growth, often increased head circumference relative to stature.
- Early thyroid hormone therapy (<1 year) is essential for normalizing head growth and achieving complete catch-up growth in children with CH.
- Delayed treatment initiation in CH can lead to irreversible effects on head size and linear growth.
Abstract:
Head circumference, height, bone age and weight were studied in 103 children with congenital hypothyroidism before and up to 8 years of thyroid replacement therapy. The patients were divided into 4 groups according to the age at start of treatment: group I (diagnosed by neonatal screening): less than 2 weeks (n = 55); group II: 1-3 months (n = 7); group III: 4-12 months (n = 15); group IV: greater than 1 year of age (n = 26). Before treatment, group I showed a head circumference significantly larger than normal and a delay in bone maturation in the presence of normal length and weight. In the other groups length as well as bone age were significantly lower than normal, head circumference, in contrast, was normal (groups II and III) or even increased (group IV). During therapy, head circumference and bone age of group I became normal as were length and weight from the beginning. In the other groups, therapy led to a further increase of head size resulting in a mean head circumference significantly larger than normal during 8 years of observation in group IV. There was a catch-up of height, bone age and weight in groups II, III and IV; mean height of late treated children (group IV), however, remained significantly lower than normal even after 8 years of therapy. - Our study shows that congenital hypothyroidism is associated with increased head circumference, either absolutely or in relation to stature. Thyroid hormone therapy resulted in a normalization of head growth when treatment was initiated early, and in a further increase when treatment was started late. There was a catch-up of height, bone age and weight; complete normalization, however, occurred only in those children treated before one year of age.