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

Background/aims: Preterm newborns with a very low birth weight (VLBW) of < 1,500 g have an atypical form of hypothyroidism with a delayed rise in TSH, necessitating a second newborn screening specimen collection. The aims of this study were to survey the compliance with second newborn screening to detect delayed TSH rise in VLBW preterm infants at a tertiary care center, and to determine the rate of atypical hypothyroidism.

Methods: Retrospective review of the records of 104 preterm VLBW infants.