Experience in neonatal screening for congenital hypothyroidism

Area of Science:

• Neonatal screening
• Endocrinology
• Public health

Background:

• Congenital hypothyroidism (CH) is a common endocrine disorder in newborns.
• Early diagnosis and treatment are crucial to prevent intellectual disability.
• Neonatal screening programs are essential for timely intervention.

Purpose of the Study:

• To evaluate the effectiveness of a neonatal screening program for congenital hypothyroidism.
• To determine the incidence and epidemiological characteristics of CH.
• To assess the impact of early treatment on neurodevelopmental outcomes.

Main Methods:

• Screening of 91,683 neonates for thyroid-stimulating hormone (TSH) levels between November 1986 and June 1991.
• Utilized chemical luminoimmunoassay (CLIA) and time-resolved fluoroimmunoassay (DELFIA) for TSH measurement.
• Confirmed cases with elevated TSH through further serum testing (T4, T3, TSH) and initiated treatment.

Main Results:

• Twenty cases of congenital hypothyroidism were confirmed, yielding an incidence of 1:4584.
• A female to male ratio of 3:2 was observed.
• Treated infants showed normal physical growth and intellectual ability, with no false negatives or missed cases identified.

Conclusions:

• The implemented neonatal screening program for CH was effective in identifying affected infants.
• Early thyroid hormone replacement therapy (equivalent to L-thyroxin 5-7.5 micrograms/kg/day) is vital for preventing developmental deficits.
• Close observation is recommended for infants with fluctuating T4 and TSH levels, but treatment initiation before 3 months of age is critical.