Quantitative ultrasound assessment of bone tissue in premature newborn twins

Abstract

Multiple pregnancy is associated with a high risk premature newborn twins (PNT) birth and the formation of low bone mass. Determining the state of bone tissue (BT) after birth is important for understanding the dynamics of its changes in the PNTs’ growth. Aim: to conduct and analyze the results of quantitative ultrasound assessment of BT in PNT. Materials and methods. In the early neonatal age, 24 pairs of twins and 39 children from singleton pregnancies (SP) born at gestational age (GA) of 30–36 weeks were examined. Pair of twins with a difference in body weight of 5% or more were involved. BT status was determined with an ultrasonic densitometer “Sunlight Omnisense 9000”, measuring SOS, m/s. Results. In GA up to 34 weeks SOS of BT in both twins did not differ from each other or from newborns from SP of the corresponding GA. In PNT, from 34 weeks of gestation and more, SOS increased (P < 0.05) in siblings with lower body weight compared to bigger one – 2925 (2887; 3036) m/s and 2866 (2801; 2895) m/s, respectively. According to correlations, the body weight of PNT was not determined as a significant factor influencing the state of BT. SOS in PNT had a weak positive correlation (R = 0.29, P < 0.05) with their GA in contrast to the strong direct correlation (R = 0.78, P < 0.05) in newborns from SP. Among the factors influencing the state of BT according to SOS in PNT, the inverse correlations with the factor of increasing the number of pregnancies (R = -0.59, P < 0.05) and with birth from monochorionic multiple pregnancies (R = -0.57, P < 0.05) were determined. Conclusions. SOS in children born in GA of 34 weeks and older was 2925 (2887; 3036) m/s in PNT with lower body weight in pairs. This value was higher (P < 0.05) than in bigger siblings and PNT born in GA less than 34 weeks. SOS in PNT had a weak correlation (P < 0.05) with their GA in contrast to children born in the same GA from SP and had no correlation with the body weight of twins. The average correlation (P < 0.05) between low SOS in PNT and the number of previous pregnancies, as well as with birth from monochorionic multiple pregnancies.