title: Association of increased cardiothoracic ratio and intrauterine growth retardation.
abstract: Clinical observation suggested an association between an increased cardiothoracic ratio (CT) and growth retardation (IUGR) in the premature neonate. To investigate this hypothesis, a case-control study was performed. Study subjects included 23 cases (IUGR) and 55 control (appropriate for gestational age [AGA]) premature infants with birthweights 2000 gm or less; Apgar scores greater than 5 at 5 minutes; no congenital heart disease; no polycythemia; no toxoplasmosis, rubella, cytomegalovirus, or herpes infection. In random order, the first chest radiograph of each infant (less than 24 hours) was reviewed by a single radiologist, unaware of the infant's growth status. The CT ratio was computed after measuring the widest internal width of the bony thorax and the cardiac diameter. Mean birthweight (+/- 1 SD) of the IUGR infants was 1161 +/- 289 g and of AGA infants was 1401 +/- 401 g (p less than 0.002); the mean gestational ages (+/- 1 SD) were 33.2 +/- 2.8 and 30.8 +/- 2.5 weeks (p less than 0.001). Mean CT for IUGR infants was 0.57 +/- 0.07 (+/- 1 SD) versus AGA infants, 0.51 +/- 0.04 (+/- 1 SD), p less than 0.001. When the infants were stratified by growth status and CT ratio, 11 of 23 IUGR and 1 of 55 AGA infants had an increased CT ratio p less than 0.0001. When birthweight and gestational age were covaried, growth status remained the best predictor of CT, p = 0.005. There is a strong association of increased CT and growth retardation in premature infants with birthweights 2000 gm or less.
authors.affiliation: Department of Pediatrics, University of Michigan Medical Center, Ann Arbor 48109-0254.
authors.forename: M E
authors.initials: ME
authors.lastname: Bozynski
authors.forename: F H
authors.initials: FH
authors.lastname: Hanafy
authors.forename: R J
authors.initials: RJ
authors.lastname: Hernandez
mesh_terms: D001724:Birth Weight; D016022:Case-Control Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology*; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D011247:Pregnancy; D013909:Thorax / Q000033:anatomy & histology*