A Study on the Bone Density in Newborn Infants: Difference of the Bone Mineral Density according to the Gestational Age and the Birth Weight

Lee, Eun Sil; Shin, Son Moon; Moon, Han Ku; Park, Yong Hoon; Choi, Kwang Hae

Abstract

To study the differenced of bone mineral density according to the gestational ages and the birth weight and get a reference data for the diagnosis of metabolic bone diseases in the newborn infants, bone mineral densities of the lumbar vertebrae were measured in fifty-three newborn infants bone at Yeungnam University Hospital from March 1, 1995 to February 28, 1997, whose gestational ages were between 28+3 and 41+3 weeks and who had no intrauterine growth retardation, using dual energy X-ray absorptiometry (X-R 26, Norland, USA) within seven days of life. 1. There was no sexual difference in bone mineral density. The bone density increased significantly as gestational age increased from 0.149+/-0.009 g/cm2 at 28-30wks to 0.229+/-0.034 g/cm2 at 39-41wks of gestational age (p<0.05), but there was no significant difference between bone mineral density at 33-34wks and 35-36wks. There was positive linear correlation netween gestational age and bone mineral density (Y=7.5?10-3X-0.082, r=0.7018, p<0.001). 2. The bone mineral density increased significantly as the birth weight increased from 0.158+/-0.020 g/cm2 in 1,000-1,499 g to 0.251+/-0.021 g/cm2 in 3,500-4,000 g of the birth weight (p<0.05), but there was no significant difference between bone mineral densities in 1,000-1,499 g and 1,500-1,999 g of the birth weight. There was positive linear correlation between the birth weight and the bone mineral density (Y=3.9?10-5X+0.093, r=0.7296, p<0.001). There were positive correlations between the bone mineral density and gestational age, and between the bone mineral density and the birth weight. It can be used as a reference data for the further study on the bone mineral metabolism in the newborn infants including preterm babies.