title: Preterm birth with antenatal corticosteroid administration has injurious and persistent effects on the structure and composition of the aorta and pulmonary artery.
abstract: BACKGROUND
  Preterm birth affects 8-12% of live births and is associated with the development of elevated arterial blood pressure and aortic narrowing in later life; this suggests that preterm birth may alter the development of arteries. Our objective was to determine the effects of preterm birth, accompanied by antenatal corticosteroid administration, on the structure of the aorta and pulmonary artery, which experience different alterations in pressure flow at birth.
  
  
  RESULTS
  At 11 wk, preterm lambs had significantly thicker aortic walls and a smaller lumen, whereas the morphometry of the pulmonary artery was unaffected. Elastin deposition was markedly increased in the aorta and pulmonary artery and smooth muscle content was reduced in the aorta only. In preterm lambs we found injury in the aorta only; controls were unaffected.
  
  
  CONCLUSIONS
  We conclude that moderate preterm birth after antenatal betamethasone can cause injury and persistent alterations in the structure and composition of the aorta, with lesser effects in the pulmonary artery. Our findings suggest that preterm birth may increase the risk of atherosclerosis and aortic aneurysms in later life.
  
  
  METHODS
  Using an established ovine model of preterm birth, lambs were born at 0.9 of gestation and underwent necropsy at 11 wk after birth; controls were born at term.
authors.affiliation: Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Monash University, Clayton, Australia.
authors.forename: Jonathan Guy
authors.initials: JG
authors.lastname: Bensley
authors.forename: Robert
authors.initials: R
authors.lastname: De Matteo
authors.forename: Richard
authors.initials: R
authors.lastname: Harding
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: Black
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000633:toxicity*; D000737:Androstenols; D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D001623:Betamethasone / Q000008:administration & dosage / Q000633:toxicity*; D002318:Cardiovascular Diseases / Q000209:etiology / Q000473:pathology; D003094:Collagen / Q000378:metabolism; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D004549:Elastin / Q000378:metabolism; D005260:Female; D005865:Gestational Age; D011247:Pregnancy; D047928:Premature Birth / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D011651:Pulmonary Artery / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D012756:Sheep
chemical_list: D000305:Adrenal Cortex Hormones; D000737:Androstenols; C046855:epostane; D003094:Collagen; D004549:Elastin; D001623:Betamethasone