Evaluation of Bone Mineral Density with Quantitative Ultrasonography in Small for Gestational Age Preterm Infant

Aim: To compare serial tibial speed of sound (SOS) values of small-for-gestational age (SGA) versus appropriate-for-gestational age (AGA) preterm infants. Material and methods: Clinical and laboratory data of preterm newborns born at 24-35 gestation week and assessed by serial tibial SOS from postnatal week 1 were retrospectively reviewed. Results: A total of 67 preterm infants, of which 44 were AGA and 23 were SGA, were included in the study. There were also serial tibial SOS measurements of the third week of 50 of these newborns and of the sixth week of 31. The mean birth weights of SGA and AGA groups were similar (1341 +/- 299 g and 1359 +/- 457 g, respectively, p = 0.59); however the mean gestational ages of SGA group were higher (33.8 +/- 2.6 weeks and 29.8 +/- 3.weeks, respectively, (p<0.001). The effects of being SGA-AGA and gestation week on tibial SOS values were calculated by univariate analysis. The tibial SOS values in the SGA and AGA groups were found to be the first week of (3051 +/- 169 m/s and 2915 +/- 116 m/s, respectively, p = 0.09), the third week of (3017 +/- 180 m/s and 2906 +/- 124 m/s, respectively, p = 0.57) and the sixth week of (2977 +/- 152 m/s and 2882 +/- 103 m/s, respectively, p = 0.38). Conclusion: Tibial SOS values at postnatal first, third and sixth week were similar in AGA and SGA preterm newborns. In order to obtain a clear conclusion about this issue, there is a need for prospective studies in which the number of samples is appropriate and serial tibial SOS measurements were compared between preterm SGA and AGA neonates matched in terms of prenatal risk factors.