ESPE Abstracts

Purpose: Recent reports indicate that being small for gestational age could be a risk factor for delayed thyroid stimulating hormone (TSH) elevation (dTSH) in preterm infants. Very few studies have investigated the development of delayed thyroid stimulating hormone elevation in small-for-gestational-age late-preterm infants with a gestational age of 34–36 weeks.

Methods: We retrospectively included 70 small-for-gestational-age (SGA) infants and 86 sex- and gestational age-matched controls who presented with normal results on initial thyroid function testing.

Results: Small-for-gestational-age infants had a significantly higher prevalence of delayed thyroid stimulating hormone elevation (15.7% vs. 3.5%, P=0.009) and increased likelihood of receiving levothyroxine treatment (11.9% vs. 2.3%, P=0.008) compared to appropriate for gestational age infants. In SGA infants, the mean age at the time of dTSH was 24 days. Development of dTSH was associated with being SGA and medical treatment with dopamine or furosemide. After adjusting for confounding factors, multiple logistic regression analysis showed that being SGA was a significant risk factor for the development of delayed thyroid stimulating hormone elevation (odds ratio: 4.81, 95% confidence interval 1.1–21.7, P=0.041).

Conclusion: SGA infants may be at risk for dTSH and may consider a second thyroid screening test around the age of 1 month.