Thymus size in preterm infants evaluated by ultrasound - A preliminary report

Purpose: To sonographically evaluate the thymic size in preterm infants. Material and Methods: In 6 healthy infants, born in gestational weeks 34-37 , and 6 infants born in weeks 24-32, the thymic volume estimate (the thymic index) was assessed. The measurements were compared to the estimates calcu lated from the prediction model for neonates. Results: The slightly preterm infants fit the prediction model. In cases wh ere the results failed to fit into the model, it was adjusted in order to c over lower birth rates. The extremely preterm infants initially had a very low thymic index but, when healthy, they reached the normal range. Conclusion: With the knowledge of the birth weight it is now possible to pr edict the thymic size in healthy infants weighing 2,070 g or more.