Effect of Prolonged Discontinuation of L-Thyroxine Replacement in a Child with Congenital Hypothyroidism

Table 1

Initial and follow-up laboratory studies.

	Initial	6 weeks	4 months	7 months	16 months
TSH (mIU/L)	1620	5.2	2.84	20.93	0.79
Free T4 (ng/dL)^1	<0.10 (<1.29)	1.41 (18.15)	1.5 (19.30)	1.1 (14.16)	1.7 (21.88)
Prolactin (ng/mL)^2	27.9 (1,213.04)	10.1 (439.13)	5.1 (221.74)	—	—
Thyroglobulin (ng/mL)^3	<0.5 (<0.5)	—	—	—	—

Values in Systeme International (SI) units are in parentheses.
¹To convert to pmol/L multiply by 12.87.
²To convert to pmol/L multiply by 43.478.
³To convert to μg/L multiply by 1.