Quantitative ultrasound measurements in premature infants at 1 year of age: the effects of antenatal administered corticosteroids.

The aim of this study was to evaluate the effects of antenatally administered glucocorticoids on bone status of preterm infants at 1 year corrected age. The study population consisted of 32 preterm infants with a gestational age of 24-34 weeks. The infants were divided into two groups according to antenatal exposure to corticosteroids. Quantitative ultrasound (QUS) assessment of bone was performed in the study infants at the corrected age of 1 year. Blood levels of carboxy-terminal propeptide of type I procollagen (PICP) and carboxy-terminal telopeptide of type I collagen (ICTP) were measured at birth and at 1 year corrected age. Levels of PICP and ICTP were significantly lower at birth in corticosteroid-exposed neonates (P < 0.05). At corrected age of 12 months ICTP levels remained significantly lower in corticosteroid-exposed infants, but we found no significant difference in levels of the bone-formation marker PICP between corticosteroid-exposed and nonexposed infants. In the majority of participant preterm infants bone speed of sound (SOS) was within age-adjusted normal values of full-term infants. There was no significant difference in bone SOS between exposed and nonexposed infants at corrected age of 12 months. There was no correlation between SOS and levels of bone markers. The results of our study indicate that, despite the suppression of fetal bone turnover at birth in corticosteroid-exposed infants, antenatal glucocorticoid treatment seems to have no long-term impact on bone status of preterm infants assessed by QUS complementary to measurement of bone-turnover markers at 1 year corrected age.