Influence of Initial Levothyroxine Dose on Neurodevelopmental and Growth Outcomes in Congenital Hypothyroidism

Seventy-two neonates detected by the neonatal screening program for congenital hypothyroidism were randomly assigned to receive one of the two initial L-T4 replacement dose: Group A received an initial replacement dose of 10-12.5 mcg/kg/die and Group B received an initial replacement dose of 12.6-15 mcg/kg/die. The adequacy of treatment were monitored closely by clinical evaluation and regular measurement of FT4 and TSH. Cognitive development were evaluated through the Griffiths Mental Development Scales at the the age of 2 yeas. Cognitive and behavioural assessment at the age of 4 years were performed using the Wechsler Preschool and Primary scale of Intelligence. Growth were evaluate at the enrolment and at each visit. Skeletal maturation were evaluated at diagnosis and at the age of 1 and 4 years. At the age of 4 years a quantitative ultrasound measurements and cardiovascular evaluation were performed.