The effects of season on fetal bone development: a study from Chinese newborn infants

This study compared bone status in infants at birth born in different seasons. Bone status was evaluated by tibial speed of sound (SOS) with a quantitative ultrasound (QUS) sonometer in 267 Chinese newborn infants. Significant differences in SOS were found in infants born in different seasons (F= 6.505, P <0.001). Infants born in summer had the lowest SOS and infants born in winters had the highest SOS. The tibial SOS of infants born in winters was 2.0% higher than those born in summers after adjustment. The effects of season on fetal bone development were discussed.