Targeted Levothyroxine Dosing in Infants With Congenital Hypothyroidism

This is a clinical study comparing targeted levothyroxine dosing based on thyroid anatomy as visualized on ultrasound (normal vs. ectopic/sublingual vs. athyreosis) to empiric levothyroxine dosing in infants with congenital hypothyroidism. Patients enrolled in the study for targeted dosing will be compared to controls obtained by retrospective chart review. The main outcome is to determine if there is a difference in the frequency of over-treatment and under-treatment during the first 6 months of therapy.

Patients in this arm will receive targeted levothyroxine dosing based on thyroid anatomy on ultrasound as follows: 10 mcg/kg for normal gland, 12 mcg/kg for ectopic gland, 15 mcg/kg for athyreosis.

Levothyroxine dose will be adjusted at the first clinic visit based on thyroid anatomy on ultrasound.

Thyroid labs (TSH and fT4/T4) will be monitored per standard care: 2 weeks after initiation of levothyroxine and once monthly during the first 6 months of treatment. The number of dose adjustments required per participant during the first 6 months of treatment were recorded.

Number of Adjustments Due to Overtreatment in Subjects With Athyreosis, Ectopic and Eutopic Thyroid Glands Compared With Controls

Inclusion Criteria: Newborns diagnosed with congenital hypothyroidism (CH). Newborns with CH who are treated by a pediatric endocrinologist at Riley Hospital for Children or satellite location. Newborns with CH who have thyroid imaging performed (thyroid ultrasound or technetium scan) at diagnosis. Exclusion Criteria: Newborns who do not have CH. Newborns with CH who have not had thyroid imaging performed at diagnosis.