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

Abstract

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.

Transient hypothyroidism in the newborn: to treat or not to treat

“…Recent studies have advocated that the course of CH is transient in many premature babies where discontinuing thyroxine supplementation is possible before 3 years of age (55,56). A recent study showed that infants with CH requiring lower L-thyroxine doses (<3.25 µg/kg) are likely to have transient CH, and thus might be re-evaluated at 12 or 24 months rather than 3 years of age (57).…”

Higher Incidence Rates of Hypothyroidism and Late TSH Rise in Preterm Very-Low-Birth-Weight Infants at a Tertiary Care Center

“…The majority of VLBW patients diagnosed with hypothyroidism were weaned off treatment by 24 months of age in some studies [35, 36]. All our patients were on treatment at discharge from NICU.…”

“…These results warrant further research to better understand the underlying causes of this high incidence and whether our single-center experience is reflective of the rates of hypothyroidism in VLBW infants across Lebanon. Although most of those newborns may prove to have transient hypothyroidism [35, 36], vigilance in screening and in obtaining second sample screenings is necessary in this high-risk population.…”

Screening and management of thyroid dysfunction in preterm infants

“…Re-evaluation is possible before 3 years of age in preterm infants. Lim et al [57] and Jung et al [58] reported that discontinuation of thyroxine supplementation is possible at the age of ≤2 when low doses of levothyroxine administration could be successfully maintained.…”