Feasibility of an Early Discontinuation of Thyroid Hormone Treatment in Very-Low-Birth-Weight Infants at Risk for Transient or Permanent Congenital Hypothyroidism.

Background/aims: This prospective study was conducted to investigate the feasibility of an early discontinuation of thyroid hormone treatment in very-low-birth-weight (VLBW) infants with congenital hypothyroidism (CH).

Methods: We enrolled VLBW infants between January 2011 and December 2012. The infants were divided into the hypothyroid and normal thyroid function groups according to the results of a thyroid function test. We performed an early off-therapy trial at 24 months of age.

Results: Of the 182 VLBW infants enrolled, 15 were lost to follow-up and 167 were finally enrolled. In total, 24 infants (14.4%) were assigned to the hypothyroid function group and were treated with thyroid hormone. Younger gestational age and a lower birth weight were associated with hypothyroid function. In the hypothyroid function group, hypothyroidism (HT) and hyperthyrotropinemia (HTT) were observed in 13 and 11 infants, respectively. There were no differences in the clinical characteristics between the HT and HTT groups. Overall, 24 infants discontinued thyroxine medication at 24 months of age after normal results had been confirmed by radiologic work-ups, including thyroid ultrasonography and technetium-99m scans. All infants were successfully weaned off thyroxine and maintained euthyroid function.

Conclusion: Early discontinuation of thyroid hormone replacement therapy is possible in the majority of VLBW infants with CH.