title: Thymus size and its relationship to the respiratory distress syndrome.
abstract: Thymic size can be affected by both exogenous and endogenous glucocorticoids. The risk of respiratory distress syndrome is reduced after maternal steroid administration. To find whether fetal lung maturity correlates with size of the thymus, the cardiothymic:thoracic ratio was measured in 167 newborn infants with and without RDS. Mean CT/T was significantly greater (0.40 vs 0.35; P less than 0.001) in those babies with RDS. This relation was independent of gestational age, although an increase in CT/T with advancing gestational age was shown. Prepartum maternal steroid administration did not result in significant involution of the cardiothymic shadow when compared with control infants with and without RDS. The CT/T may be of use in predicting which premature babies are more likely to develop RDS.
mesh_terms: D005260:Female; D005333:Fetus / Q000033:anatomy & histology; D005865:Gestational Age; D006321:Heart / Q000033:anatomy & histology; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000000981:diagnostic imaging / Q000209:etiology*; D011247:Pregnancy; D011859:Radiography; D012127:Respiratory Distress Syndrome, Newborn / Q000209:etiology*; D013950:Thymus Gland / Q000033:anatomy & histology*